jo documentaion

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ContentsDeveloper Guide:

About

Philosophy

Summary

Building

Directory Map

Quick StartClass Hierarchy

Class Patterns

Data Driven Controls

Observer Pattern

Supported Platforms

Release Notes

License

API Reference:

Core

Data Layer

UI Widgets

Index:

Keywords

Jo JavaScript Framework for HTML5

Jo HTML5 Mobile App Framework Documentaion http://joapp.com/docs/index.html

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About

Jo is a lightweight JavaScript framework designed for HTML5 apps.

jo does:

Embrace JavaScript's object model and loosely typed nature

Leverage CSS3 to handle as much of the pretty presentation and animation as

possible

Provide a consistent and modular event model between objects

Wrap DOM and device-specific events into a cohesive gesture system

Insulate developers from different persistent storage solutions

Play nicely with other libraries like PhoneGap

jo doesn't:

Use a lot of resources

Depend on other frameworks

Have a lot of browser dependent code

Require detailed knowledge of the DOM

Force you to deeper into its framework than you want to go

Use $ and other arcane looking symbols in place of proper identifiers

Author:

Dave Balmer: davebalmer.wordpress.com , follow @balmer on Twitter , or email

[email protected]

Downloads:

Version 0.4.1 is the latest stable release, check the Release Notes for details.

Available from GitHub as a git repo or a zip file .

Philosophy

If you want to jam an existing web page into an application framework, jo probably isn't for you. jo


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is designed to create applications. While it will play nicely with a mixture of new and old web

development techniques, it uses HTML5 as a development stack and does not require direct DOM

manipulation.

Application Stack:

JavaScript Application

jo

PhoneGap (optional)

joView joEvent joDataSource

CSS3 Canvas DOM Events XHR SQLite Device OS

Documentation

All documentation for the framework is based on Markdown and provides a simple, natural and

flexible way to document the code. This simple set of perl scripts has become its own tool called

joDoc.


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Summary

Jo is a JavaScript framework for HTML5 capable browsers and devices. It was originally designed

to work on mobile platforms as a GUI and light data layer on top of PhoneGap. Since its creation, Jo

has also been tested successfully as a lightweight framework for mobile browsers, newer desktop

browsers, and even Dashboard widgets.

Building

It's pretty easy to build on your own, but to get the most out of it you'll want to get a minifier like

jsmin or the YUI Compressor. Minified and gzipped, Jo weighs in around 9K with no other

JavaScript library dependancies.

Mac OSX, Linux & BSD:

cd jo

./build

Windows:

cd jo

build.bat

If you're not up for building the library yourself, there's nothing wrong with downloading the latest

stable release, all built and ready to plug in from: jo /downloads">GitHub Downloads

Directory Map

Important files in the directory tree are:

js/jo_min.js

This is the jo library bundled and minified, ready to drop into your project. You will

need to build the library to make this file (as well as the un-minified version jo.js

which is useful for debugging).


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css/aluminum

This is a CSS3 bundle ready to ship your app with. Also serves as a good example of

modern HTML5 styling capabilities. Looks pretty bad in IE up through version 8.

css/jo.css

This is a newer base CSS theme for Jo, preferred over Aluminum for now. Built with

Less CSS compiler.

docs/*.mdown

These are supplimental doc files which are used by joDoc to build out the developer

guide portions of the documentation.

Quick Start

index.html:

The complete jo library is small, so in most cases you'll just want to pull it all in, like this:

<html>

<head>

<link rel="stylesheet" type="text/css" href="css/aluminum.css">

<link rel="stylesheet" type="text/css" href="css/webkit.css">





</head>

<body>





<script src="jo_min.js"></script>



<script src="hello.js"></script>

</body>

</html>

If you're using jo to create all the UI for your application, you won't need any content or tags in

your index.html file.


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Since the framework is highly dependent on CSS, your mileage may vary across platforms. In

particular, Internet Explorer before 9 will have limited eye candy and no animated transitions.

You can also completely skin your app with your own CSS, or augment the basic jo CSS to suit

your purposes.

Since jo is geared for HTML5 applications, I recommend you develop and test your apps with

Safari or Chrome before moving to mobile devices. In fact, this makes the code/test/debug cycle

go very quickly.

hello.js:

jo has some initialization which should only be done when your browser is ready to have its DOM

fiddled with, so you may want to wrap your code in a function that's called when your page loads,

or your device signals that your app is ready to go.

The simplest UI would be something like:

// initialize jo

jo.load();

// define a wrapper for document.body

var scn = new joScreen();

// setup your UI

scn.alert("Hello, Jo!", "This is a simple alert.");

Something more interesting would look like:

// initialize jo

jo.load();

// setup a stack and screen

var stack = new joStackScroller();

var scn = new joScreen(stack);

// create our view card

var card = new joCard([

new joTitle("Hello"),

new joCaption("Hello World!"),

new joDivider(),

new joButton("OK").selectEvent.subscribe(function() {

stack.hide();

})

]);


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// put the card on our view stack

stack.push(card);

Notice above that jo supports "chaining", meaning you can make successive calls inline to a given

object (see the joButton line above for an example).

Of course, it is recommended you use more robust OOP coding patterns to make a proper

application. While there's nothing illegal about putting everything in global space in a single

JavaScript file, but if you're looking to build something big or more easy to maintain, I recommend

you check out "JavaScript: the Good Parts" by Doug Crockford (O'Reilly Press).

Class Hierarchy

The following is a class hierarchy for the framework, organized by general function.

User Interface:

joView

joContainer

joCaption

joCard

joDialog

joFlexcol

joFlexrow

joFooter

joForm

joGroup

joNavbar

joPopup

joScreen

joScroller

joShim

joStack

joStackScroller

joTitle

joToolbar

joControl


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joButton

joBackButton

joCaption joExpando

joSelect

joHTML

joInput

joDateTime

joPasswordInput

joTextarea

joLabel

joList

joMenu

joSelectList

joTabBar

joTable

joKnob

joSlider

joToggle

joOption

joDivider

Data:

joDatabase

joDataSource

joFileSource

joProperty

joRecord

joSQLDataSource

joYQL

joFile

joScript

Events:

joEvent

joSubject

joGesture


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Processing:

joChain joDefer

joWait

Utility:

joDOM

joInterface

joJSON

joLocal joString

joTime

Debugging:

joLog

Application:

jo

joClipboard

joDevice

joFocus

joPreference

joUser

Class PatternsInstead of a complex set of pseudo-class methods, jo uses a few simple coding patterns: singleton,

base class, subclass, and module. All of these are found in modern JavaScript implementations. A

good reference to have while developing your app is JavaScript: The Good Parts by Douglas

Crockford (O'Reilly Press)

Singleton:

The pattern for creating a singleton is really just an object literal. For example:


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MyApp = {

init: function() {

// some sort of initialization code goes here

},

mymethod: function() {

// some custom method

},

// properties can also be declared inline

myproperty: true

};

Base Class:

Prototypal inheritance does well with "fat" base classes which do most everything you anticipate a

subclass would want. This type of inheritance benefits greatly from shallow/wide prototypes for a

number of reasons. A base class looks something like:

MyClass = function(x) {

// constructor

this.x = x;

};

MyClass.prototype = {


// some method

},

myothermethod: function() {

// another method

}

};

Subclass:

Strictly speaking, JavaScript doesn't have classes and subclasses. But it does know how to make

copies of an object, and keeps track of "inheritance" through its prototype chain. A subclass in jo

looks something like this:

MySubclass = function(x, y) {

//constructor

this.y = y;

// call to our "superclass" constructorMyClass.call(this, x);


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};

MySubclass.extend(MyClass, {

mynewmethod: function() {

// this subclass has its own new method

}

});

A couple things to note. jo augments the Function object in JavaScript to have an extend() method.

This is just some syntactic sugar which makes it easier to extend an object, giving us a pseudo-

subclass with syntax that's not too awkward. The advantage here is we're using JavaScript's natural

object model behind the scenes. We're not creating any extra fluff, just automating the process

somewhat.

Note that objects created using prototypal inheritance also get the benefit of using JavaScript's

built-in instanceof operator which works up the prototype chain. For example:

// given this new subclass

var someobject = new MySubclass(1, 2);

// both of these tests are "true"

joLog(someobject instanceof MySubclass);

joLog(someobject instanceof MyClass);

You may also notice a "call to super" comment in our MySubclass constructor. This is a convenient

coding pattern which makes it easier to create subclasses, with methods that augment the

superclass' functionality. Like this:

MySubclass.extend(MyClass, {

mynewmethod: function() {

// this subclass has its own new method

},


this.x += 5;

// call super's mymethod() with this object's context

MyClass.prototype.mymethod.apply(this, arguments);

}

});

It may look slightly odd at first, but this approach gives us more of the benefits of subclassing

you'd find in other languages without having to step outside of JavaScript's natural object model.


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Data Driven Controls

Jo isn't just a pretty face with some DOM fiddling and standard DOM events. It also has a versatile

application-level event model (see Observer Pattern). In addition, Jo has a simple event-driven layer

for asynchronous data storage and retrieval using extensions of joDataSource.

As a matter of convenience, all children of joControl (which includes most list or widget-driven UI

elements) can be easily tied to data.

The most convenient for most purposes is joRecord. This class wraps a property list, which can be

used to save or load using whatever your application requires. In addition, this class allows you tolink a UI control to the data in one quick action.

For more on this, check out the joRecord docs which include an example or two.

joDoc

joDoc is a plain text code documentation scheme for JavaScript. It was created out of frustration felt

working with various documentation systems available.

Source code formatting:

/**

myClass

=======

This is my class. It rocks, and this is its _description_, which also

rocks.

Extends

-------

- someOtherClass

Methods

-------

- setName(name)

Where `name` is a `String`.

Use

---

// here is some sample code which shows how to use this class


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var x = new myClass(name);

> Note: use of the `name` reserved word is probaly a bad idea.

*/

Comment placement:

You can put your comments for your code either:

in your source code (anywhere and in as many pieces as you want) denoted with /** ...

*/ multiline-comment blocks

1.

separate markdown (*.mdown) files, probably (tho not necessarily) named to match your

JavaScript files

2.

Can't get much more flexible than that.

Comparison:

JavaScript is an extremely expressive language which is often difficult to describe in terms of meta

data and fields. Often, important information that needs to be documented just doesn't fit into a

neat, tidy spot.

jsdoc:

jsdoc in its various incarnations and some of its spawn like yuidoc take the approach that "what is

good for Java is good for JavaScript". All these flavors are based on javadoc formatting, and have

been in use for some time.

Aside from the regimented markup being a bit odd to read (admit it, even Java developers don't

love it), it suffers from an inflexibility with regard to all the coding patterns available with

JavaScript. Basically, it fails due for the same reason that all JavaScript libraries which attempt tosubvert JavaScript's natural object model fail. These solutions, while influential in the idea that some

form consistent coding approach could help us make better code, are not in the spirit of embracing

JavaScript.

Why then do so many developers continue to use a documentation tool which was born of the same

well-meaning yet misguided logic of "let's pretend JavaScript is Java"?

Natural Docs:

Excellent effort, but complex to set up and also tries to make a regimented system for documenting


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source code. It is extendable, but again, we have a documentation solution which is trying to force

JavaScript into a more limited set of features.


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Observer Pattern

jo uses a variant on this OOP pattern quite extensively for notifications between objects.

When you think about JavaScript, most of the interesting things that happen are asynchronous: XHR

calls, loading scripts, accessing at database, making device-specific system calls; even user

interactions are all asynchronous in nature.

Instead of trying to hide from this often complex-looking stuff, jo embraces it and provides a

scheme to wrap all these different use cases in a consistent interface using joSubject.

PhoneGap

This excellent, lightweight mobile application library by Nitobi neutralizes device differences and

provides a stable webkit application shell. Jo is designed to work with PhoneGap out of the box,

and it's highly recommended.

LawnChairAnother tool by Nitobi , LawnChair is a client-side storage solution which stores JSON objects (in

SQLite or whatever the device supports). It looks promising, and the jo core has a special subclass

of joDataSource called joLawn which folds Nitobi's library into the Jo event model.

Supported Platforms

Jo is built on HTML5, so anything with decent support for these emerging standards should work

with Jo. The list of devices and platforms you can distribute your apps on is growing, but here's a

list of

Mobile Apps:

Most require PhoneGap to create a native app "shell". webOS doesn't require PhoneGap, but it is

useful for some things.

iOS 3+ for iPhone, iPad, iPod Touch


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Android 2.1+

webOS 1.4+

Symbian ^ 3

It's been reported that Jo works great with newer releases of Blackberry, but I haven't done any

testing with it yet.

Mobile Browsers:

All the mobile app platforms supported by Jo will work, but note that in most cases you'll be

fighting against the browser scroller (Android and webOS, I'm looking at you), and in some cases

event and rendering bugs will make life interesting and might require some CSS fiddling.

Desktop Apps:

HTML5 is making its way into desktop applications. Both native Mac OSX and Windows require

special builds of PhoneGap.

ChromeOS

Windows

Mac OSX 10.5+

Mac OSX DashBoard Widgets

It's been reported that Jo will work with Adobe AIR, but I haven't done any testing with it.

Desktop Browsers:

In general, all modern browsers which have decent HTML5 support will work well with Jo and its

CSS3. Note that Internet Explorer and FireFox 3.x can work, but you will have to play with the CSS

to get things going.

Safari 5+

Chrome 9+

Opera 10+

FireFox 4+

Internet Explorer 8+

For browsers, you will want to include css/browser.css in your project to revert joScroller and

joStackScroller to use native scrollbars.


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Release Notes

Jo 0.4.1:

Emergency fix for joScroller on iOS, was affecting performance and tapability on

controls.

Jo 0.4.0:

Added new joSlider control and corresponding josliderthumb to CSS

Added css/browser.css for cases where you want to allow the browser to handle

scrolling purely with overflow:scroll

Tweaked joScroller, including removed the 50px fixed "bump" size (you can add it

back if you want)

Tweaked default CSS, made some controls less "roundy", thinned border on

joToggle

Changed readOnly and editable methods to setReadOnly()

Fixed some broken method chaining in joSound, joNavbar and a few other places

Important fixes in joDataSource, joRecord, joProperty and joList relating to the dataproperty

Fixed background image bug in joMenu

Fixed enable/disable methods for joButton and joControl

Fixed joEvent capture method to properly return event handler reference

Added resizeEvent to joGesture

Added clientX/clientY to joEvent

Added optional parameter passing for joCache get() method

Added pageOffsetTop and pageOffsetLeft methods to joDOM

Updated docs for joDOM, joEvent, joFileSource, jo, joControl, joSlider, joSound, joStack, joTable and joView

Jo 0.3.0:

New data methods: joFile, joFileSource, joRecord, joYQL

New widgets: joToggle, joExpando, joSelect, joOption, joNavbar

Even more improved joScroller performance, and the beginnings of horizontal and

free scroll support

Better "downgraded" scroller experience for less fancy browsers


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Changed default tags for input fields to input, etc.

New samples for file loading, YQL and a "kitchen sink" sample (which is more of a

bathroom sink; look for - more in the samples/test.html for now)New CSS default theme (built with Less CSS for those who are using our git repo)

Added joInterface, a method which will slurp HTML into Jo objects (experimental,

read the docs please)

Definitely check out the docs for joRecord as it's even easier to bind UI controls to a

data object

joPreference has been deprecated for now; see joRecord

joYield has been renamed to joDefer

CSS Skinning

jo makes extensive use of CSS for its widgets. As a result, it's extremely easy to skin and adapt

your user interface for different devices. The project will have a community-driven theme collection

to help reduce development time by choosing a stylesheet that most closely matches your

application (or device native controls).

HTML TagsOne feature jo exploits is the fact that modern browser engines treat unknown tags as -- tags. So

instead of mucking up your application's DOM and CSS space with a horde of div tags with

different CSS classes, it uses namespaced tags which are outside of your document's typical CSS

name space (except body).

Special Tag Examples:

<jocard>

<jotitle>My title</jotitle>

<jogroup>

<jolabel>Username</jolabel>

<input type="text">

<jodivider></jodivider>

<jobutton>Save</jobutton>

</jogroup>

</jocard>

One side benefit of this is that it is possible to load styled HTML content from another source and


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not have that content's CSS corrupt your application's user interface.

Bottom line here is the special UI controls you add with Jo can coexist with your standard HTML

content-driven tags without undue CSS headaches.

See joInterface and joView for more uses of direct HTML and DOM nodes which are common for

all UI elements.

License

Copyright 2010 Dave Balmer, Jr. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted

provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions

and the following disclaimer.

1.

Redistributions in binary form must reproduce the above copyright notice, this list of

conditions and the following disclaimer in the documentation and/or other materials

provided with the distribution.

2.

THIS SOFTWARE IS PROVIDED BY DAVE BALMER, JR. "AS IS" AND ANY EXPRESS OR

IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

DISCLAIMED. IN NO EVENT SHALL DAVE BALMER, JR. OR CONTRIBUTORS BE LIABLE

FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER

IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR

OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF

ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those of the authors

and should not be interpreted as representing official policies, either expressed or implied, of Dave

Balmer, Jr.


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jo

Singleton which the framework uses to store global infomation. It also is responsible for initializing

the rest of the framework, detecting your environment, and notifying your application when jo is

ready to use.

Methods:

load()

This method should be called after your DOM is loaded and before your app uses jo.Typically, you can call this function from your document's onLoad method, but it is

recommended you use more device-specific "ready" notification if they are available.

getPlatform()

Returns the platform you're running in as a string. Usually this is not needed, but can

be useful.

getVersion()

Returns the version of jo you loaded in the form of a string (e.g. 0.1.1).

matchPlatform(string)

Feed in a string list of desired platforms (e.g. "mozilla chrome ipad"), and

returns true if the identified platform is in the test list.

Events:

loadEvent

unloadEvent

These events are fired after jo loads or unloads, and can be used in your application

to perform initialization or cleanup tasks.

Function

jo extends the Function object to add a few goodies which augment JavaScript in a farily


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non-intrusive way.

Methods:

extend(superclass, prototype)

Gives you an easy way to extend a class using JavaScript's natural prototypal

inheritance. See Class Patterns for more information.

bind(context)

Returns a private function wrapper which automagically resolves context for this

when your method is called.

HTMLElement

This is a standard DOM element for JavaScript. Most of the jo views, continers and controls deal

with these so your application doesn't need to.

Methods:

Not a complete list by any means, but the useful ones for our purposes are:

appendChild(node)

insertChild(before, node)

removeChild(node)

Properties:

jo uses these properties quite a bit:

innerHTML

className

style

joCache

A singleton which makes it easy to setup deferred object creation and cached results. This is a

performance menchanism initially designed for UI views, but could be extended to handle data


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requests and other object types.

Methods:

set(key, call, context)

Defines a factory (call) for building an object keyed from the key string. The

context argument is optional, but provides a reference for this.

get(key)

Returns an object based on the key string. If an object has not been created which

corresponds to the key, joCache will call the constructor defined to create it and storethe reference for future calls to get().

Use:

Defining a view for on-demand use:

joCache.set("home", function() {

return new joCard([

new joTitle("Home"),

new joMenu([

"Top Stories",

"Latest News",

"Old News",

"No News"

])

]);

});

Displaying a view later:

mystack.push(joCache.get("home"));

// the first call to get() will instantiate

// the view, subsequent calls will return the

// view that was created the first time

// you can pass parameters into your view factory

var x = joCache.get("home", "My Title");

// note that if you want to use joCache to cache

// views which differ based on parameters passed in,

// you probably want your own caching mechanism instead.


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joChain

Class which strings asyncronous calls together.

Methods:

add(Function, context, data)

start()

stop()

next()

joClipboard

Singleton which abstracts the system clipboard. Note that this is a platform dependant interface. By

default, the class will simply store the contents in a special joPreference named "joClipboardData"

to provide clipboard capabilities within your app.

Methods:

get()

set(String)

Low level methods which use just strings. At this time, you will need to stringify

your own data when setting, and extract your data when getting.

cut(joControl)

copy(joControl)

paste(joControl)

In serious need of rework; doesn't meet original goal of sequencing these calls. This class might

also become deprecated.“ „

Even if you think you're just going to use the default behavior, it is recommended that you

never manipulate the "joClipboardData" preference directly.“ „


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High level methods which work with any joControl or subclass. If a control supports

selections, cut() will automatically remove the selection after copying its contents.

Otherwise, cut() will work the same as copy().

joDOM

Singleton with utility methods for manipulating DOM elements.

Methods:

get(id)

Returns an HTMLElement which has the given id or if the id is not a string returns

the value of id.

create(type, style)

Type is a valid HTML tag type. Style is the same as setStyle() method. Returns anHTMLElement.

// simple

var x = joDOM.create("div", "mycssclass");

// more interesting

var x = joDOM.create("div", {

id: "name",

className: "selected",

background: "#fff",

color: "#000"

});

setStyle(tag, style)

Style can be an object literal with style information (including "id" or "className") or

a string. If it's a string, it will simply use the style string as the className for the new

element.

Note that the preferred and most cross-platform method for working with the DOM

Note: this is not working yet, steer clear (or contribute some working code!)“ „


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is to use className and possibly id and put your actual style information in your

CSS file. That said, sometimes it's easier to just set the background color in the code.

Up to you.

getParentWithin(node, ancestor)

Returns an HTMLElement which is the first child of the ancestor which is a parent of

a given node.

addCSSClass(HTMLElement, classname)

Adds a CSS class to an element unless it is already there.

removeCSSClass(HTMLElement, classname)

Removes a CSS class from an element if it exists.

toggleCSSClass(HTMLElement, classname)

Auto add or remove a class from an element.

pageOffsetLeft(HTMLElement) and pageOffsetHeight(HTMLElement)

Returns the "true" left and top, in pixels, of a given element relative to the page.

applyCSS(css, stylenode)

Applies a css string to the app. Useful for quick changes, like backgrounds and other

goodies. Basically creates an inline <style> tag. This method returns a reference to

the new <style> tag, which you can use with removeCSS() and subsequent calls to

applyCSS() as the stylenode argument.

loadCSS(filename)

Works the same as applyCSS() but loads the CSS from a file instead of a string.

removeCSS(stylenode)

Removes a <style> tag created with applyCSS() or loadCSS().

joEvent

Singleton with DOM event model utility methods. Ideally, application-level code shouldn't have to


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use this, but library code does.

Methods:

on(HTMLElement, event, Function, context, data)

Set a DOM event listener for an HTMLElement which calls a given Function with an

optional context for this and optional static data. Returns a reference to the handler

function, which is required if you need to remove() later.

capture(HTMLElement, event, function, context, data)

This is the same os on(), but captures the event at the node before its children. If indoubt, use on() instead.

remove(HTMLElement, event, handler)

Removes a previously declared DOM event. Note that handler is the return value of

the on() and capture() methods.

stop(event)

Stop event propogation.

preventDefault(event)

Prevent default action for this event.

block(event)

Useful for preventing dragging the window around in some browsers, also

highlighting text in a desktop browser.

getTarget(event)

Returns the HTMLElement which a DOM event relates to.

joLog

Wrapper for console.log() (or whatever device-specific logging you have). Also could be

extended to send log information to a RESTful service as well, handy for devices which don't have

decent logging abilities.


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Use:

It's an all-in-one utility that's smart enough to ferret out whatever you throw at it and display it inthe console.

joLog("x=", x, "listdata=", listdata);

Basically, fill it up with strings, variables, objects, arrays and the function will produce a string

version of each argument (where appropriate; browser debuggers tend to display objects nicely) in

the same console line. Simple, effective, easy to use.

joSubject

Class for custom events using the Observer Pattern. This is designed to be used inside a subject to

create events which observers can subscribe to. Unlike the classic observer pattern, a subject can

fire more than one event when called, and each observer gets data from the subject. This is very

similar to YUI 2.x event model.

You can also "lock" the notification chain by using the capture() method, which tells the event to

only notify the most recent subscriber (observer) which requested to capture the event exclusively.

Methods:

subscribe(Function, context, data)

Both context and data are optional. Also, you may use the Function.bind(this)

approach instead of passing in the context as a separate argument. All subscribers

will be notified when the event is fired.

unsubscribe(Function, context)

Does what you'd think. The context is only required if you used one when you set

up a subscriber.

capture(Function, context, data)

Only the last subscriber to capture this event will be notified until it is released. Note

that you can stack capture() calls to produce a modal event heiarchy. Used in

conjunction with the resume() method, you can build an event chain where each

observer can fire the next based on some decision making.


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release(Function, context)

Removes the most recent subscription called with capture(), freeing up the next

subscribers in the list to be notified the next time the event is fired.

fire(data)

Calls subscriber methods for all observers, and passes in: data from the subject, a

reference to the subject and any static data which was passed in the subscribe()

call.

resume(data)

If you used capture() to subscribe to this event, you can continue notifying other

subscribers in the chain with this method. The data parameter, as in fire(), is

optional.

Use:

In the subject (or "publisher") object:

// inside the Subject, we setup an event observers can subscribe to

this.changeEvent = new joSubject(this);

// to fire the event inside the Subject

this.changeEvent.fire(somedata);

In the observer (or "subscriber") object:

// simple case, using Function.bind()

somesubject.changeEvent.subscribe(this.mymethod.bind());

// explicit context (this)

somesubject.changeEvent.subscribe(this.mymethod, this);

// optional data which gets passed with the event fires

somesubject.changeEvent.subscribe(this.mymethod, this, "hello");

This is a very flexible way to handle messages between objects. Each subject may have multiple

events which any number of observer objects can subscribe to.


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joTime

Time utility functions. More will be added, but only as needed by the framework. There are entire

libraries dedicated to extensive datetime manipulation, and Jo doesn't pretend to be one of them.

Methods:

timestamp()

Returns a current timestamp in milliseconds from 01/01/1970 from the system clock.

Constants:

SEC, MIN, HOUR, DAY

Convenience global constants which make it easier to manipulate timestamps.

Use:

var twoHoursLater = joTime.timestamp() + (HOUR * 2);

joDefer

Utility function which calls a given method within a given context after n milliseconds with optional

static data.

Use:

joDefer(Function, context, delay, data);

Note that delay defaults to 100ms if not specified, and data is optional.

joYield

Deprecated, use joDefer instead.


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joDatabase

Wrapper class for WebKit SQLite database.

Methods:

open(datafile, size)

datafile is a filename, size is an optional parameter for initial allocation size for the

database.

close()

now()

Deprecated convenience method which returns a SQLite-formatted date string for use

in queries. Should be replaced with a utility function in joTime.

joDataSource

Wraps data acquisition in an event-driven class. Objects can subscribe to the changeEvent to

update their own data.

This base class can be used as-is as a data dispatcher, but is designed to be extended to handle

asynchronous file or SQL queries.

Methods:

set()

get()

clear()

setQuery(...)

getQuery()

load()

refresh()

Events:

changeEvent


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errorEvent

joFileSource

A special joDataSource which loads and handles a file. This class wraps joFile.

Extends:

joDataSource

joFile

A utility method which uses XMLHttpRequest to load a text-like file from either a remote server or

a local file.

Calling:

joFile(url, call, context, timeout)

Where:

url is a well-formed URL, or, in most cases, a relative url to a local file

call is a function to call when the operation completes

context is an optional scope for the function to call (i.e. value of this). You can also

ignore this parameter (or pass in null and use Function.bind(this) instead.

timeout is an optional parameter which tells joFile to wait, in seconds, for a

Under construction, use with care.

“ „

Note that some browsers and mobile devices will not allow you to load from just any URL,

and some will restrict use with local files especially (I'm looking at you, FireFox).

If your aim is to load JavaScript-like data (also, JSON), you may want to look at joScript

instead, which uses script tags to accomplish the job.

“„


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response before throwing an error.

Use:

// simple call with a global callback

var x = joFile("about.html", App.loadAbout);

// an inline function

var y = joFile("http://joapp.com/index.html", function(data, error) {

if (error) {

console.log("error loading file");

return;

}

console.log(data);

});

joPreference

A class used for storing and retrieving preferences in your application.

The interface for this is changing. joPreference will become a specialized application-level extension of joRecord in the near future. Until then, you should use joRecord to achieve this use-case.

Extends:

joRecord

joRecord

An event-driven wrapper for an object and its properties. Useful as a data interface for forms and

other collections of UI controls.

Extends:

joDataSource

Methods:

link(property)


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Returns a reference to a joProperty object which can be used with UI controls

(children of joControl) to automatically save or load data based on user interaction.

save()

Saves the object's data. The base class does not itself save the data; you will need to

make your own action for the save method, or have something which subscribes to

the saveEvent.

load()

Loads the object's data, and fires off notifications to any UI controls which are linked

to this joRecord object. Same as thesave()

method, you will have to make thisfunction do some actual file loading if that's what you want it to do.

getProperty(property)

setProperty(property, value)

Get or set a given property. Used in conjunction with setAutoSave(),

setProprty() will also trigger a call to the save() method.

getDelegate(property)

Returns a reference to the joProperty object which fires off events for data changes

for that property. If none exists, one is created. This method is used by the link()

method, and can be overriden if you extend this class to provide some other flavor

of a joDataSource to manage events for your properties.

Use:

// setup a joRecord

var r = new joRecord({

user: "Jo",

password: "1234",

active: true

});

// bind it to some fields

var x = new joGroup([

new joLabel("User"),

new joInput(r.link("user")),

new joLabel("Password"),

new joPasswordInput(r.link("password")),


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new joFlexBox([

new joLabel("Active"),

new joToggle(r.link("active"))

])

]);

And if you want the data to be persistent, or interact with some cloud service, you'll need to do

something like this:

// make something happen to load the data

r.load = function() {

// some AJAX or SQL call here

};

// make something happen to save the data

r.save = function() {

// some AJAX or SQL call here

};

You could also make your own subclass of joRecord with your own save and load methods using

extend() like this:

var preferences = function() {

// call to the superclass constructor

joRecord.apply(this, arguments);

};

preferences.extend(joRecord, {

save: function() {

// do an AJAX or SQL call here

},

load: function() {

// do an AJAX or SQL call here

}

}

See Class Patterns for more details on this method of "subclassing" in JavaScript.

joProperty

Used by joRecord to provide an event-driven binding to properties. This class is instantiated by

joRecord and not of much use on its own.


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Extends:

joDataSource

Use:

See joRecord for examples.

joScript

Script tag loader function which can be used to dynamically load script files or make RESTful callsto many JSON services (provided they have some sort of callback ability). This is a low-level utility

function.

Calling:

joScript(url, callback, context, errorcallback, errorcontext)

url

callback is a function (supports bind, in which case context is optional)

context (usually this, and is optional)

Returns:

Calls your handler method and passes a truthy value if there was an error.

Use:

joScript("myscript.js", function(error, url) {

if (error)

console.log("script " + url + " didn't load.");

}, this);

joSQLDataSource

Need a URL with some examples of this.“ „


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SQL flavor of joDataSource which uses "HTML5" SQL found in webkit.

Methods:

setDatabase(joDatabase)

setQuery(query)

setParameters(arguments)

execute(query, arguments)

Events:

changeEvent

Fired when data is loaded after an execute() or when data is cleared.

errorEvent

Fired when some sort of SQL error happens.

Extends:

joDataSource

joYQL

A joDataSource geared for YQL RESTful JSON calls. YQL is like SQL, but for cloud services.

Pretty amazing stuff:

The Yahoo! Query Language is an expressive SQL-like language that lets you query, filter,

and join data across Web services. With YQL, apps run faster with fewer lines of code and a

smaller network footprint.

Yahoo! and other websites across the Internet make much of their structured data available to

developers, primarily through Web services. To access and query these services, developers

traditionally endure the pain of locating the right URLs and documentation to access and

query each Web service.

With YQL, developers can access and shape data across the Internet through one simple

language, eliminating the need to learn how to call different APIs.

“

„


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Yahoo! Query Language Home

Use:

A simple one-shot use would look like:

// setup our data source

var yql = new joYQL("select * from rss where url='http://davebalmer.wordpress.com'");

// subscribe to load events

yql.loadEvent.subscribe(function(data) {

joLog("received data!");

});

// kick off our call

yql.exec();

A more robust example with parameters in the query could look something like this:

// quick/dirty augmentation of the setQuery method

var yql = new joYQL();

yql.setQuery = function(feed, limit) {

this.query = "select * from rss where url='"

+ feed + "' limit " + limit

+ " | sort(field=pubDate)";

};

// we can hook up a list to display the results

var list = new joList(yql).attach(document.body);

list.formatItem = function(data, index) {

var html = new joListItem(data.title + " (" + data.pubDate + ")", index);

};

// later, we make our call with our parameters

yql.exec("http://davebalmer.wordpress.com", 10);

Methods:

setQuery()

Designed to be augmented, see the example above.

exec()

Extends:


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joDataSource


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joBusy

The idea here is to make a generic "spinner" control which you can overlay on other controls. It's

still in flux, don't use it just yet.

Extends:

joView

Methods:

setMessage(status)

You can update the status message in this busy box so users have a better idea why

the busy box is showing.

joButton

Button control.

// simple invocation

var x = new joButton("Done");

// optionally pass in a CSS classname to style the button

var y = new joButton("Cancel", "cancelbutton");

// like other controls, you can pass in a joDataSource

// which could be useful, so why not

var z = new joButton(joPreference.bind("processname"));

Extends:

joControl

Methods:

enable()

disable()


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joCaption

Basically, a paragraph of text.

Extends:

joControl

joCard

Special container for card views, more of an application-level view.

Extends:

joContainer

Methods:

activate()

deactivate()

These methods are called automatically by various joView objects, for now joStack is

the only one which does. Basically, allows you to add application-level handlers to

initialize or cleanup a joCard.

joCollectDEPRECATED use joInterface instead. This function is planned to die when jo goes beta.

joContainer

A view which is designed to contain other views and controls. Subclass to provide different layout

types. A container can be used to intantiate an entire tree of controls at once, and is a very powerful

UI component in jo.


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Use:

// plain container

var x = new joContainer();

// HTML or plain text

var y = new joContainer("Some HTML");

// HTMLElement

var w = new joContainer(joDOM.get("mydiv"));

// nested inline structure with text, HTML, joViews or HTMLElements

var z = new joContainer([

new joTitle("Hello"),

new joList([

"Red",

"Green",

"Blue"

]),

new joFieldset([

"Name", new joInput(joPreference.bind("name")),

"Phone", new joInput(joPreference.bind("phone"))

]),

new joButton("Done")

]);

// set an optional title string, used with joNavbar

z.setTitle("About");

Extends:

joView

Events:

changeEvent

Methods:

setData(data)

The constructor calls this method if you provide data when you instantiate (see

example above)

push(data)


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Same support as setData(), but places the new content at the end of the existing

content.

setTitle(string)

getTitle(string)

Titles are optional, but used with joStack & joStackScroller to update a joNavbar

control automagically.

joControl

Interactive, data-driven control class which may be bound to a joDataSource, can receive focus

events, and can fire off important events which other objects can listen for and react to.

Extends:

joView

Events:

changeEvent

selectEvent

Methods:

setValue(value)

Many controls have a value in addition to their data. This is particularly useful for

joList, joMenu, joOption and other controls which has a list of possibilities (the

data) and a current seletion from those (the value).

enable()

disable()

Enable or disable the control, pretty much does what you'd expect.

focus()

blur()


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Manually control focus for this control.

setDataSource(joDataSource)

Tells this control to bind its data to any joDataSource or subclass.

setValueSource(joDataSource)

Tells this control to bind its value to any joDataSource type.

setReadOnly(state)

Certain controls can have their interaction turned off. State is either true or false.

See Also:

joRecord and joProperty are specialized joDataSource classes which make it simple to

bind control values to a data structure.

joDialog

This is a higher level container that wraps a joPopup with a joShim.

joDivider

Simple visual divider.

Extends:

joView

joExpando

A compound UI element which allows the user to hide/show its contents. The first object passed in

becomes the trigger control for the container, and the second becomes the container which expands

and contracts. This action is controlled in the CSS by the presence of the "open" class.

Use:


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This is a typical pattern:

// normal look & feel

var x = new joExpando([

new joExpandoTitle("Options"),

new joExpandoContent([

new joLabel("Label"),

new joInput("sample field")

])

]);

Note that joExpando doesn't care what sort of controls you tell it to use. In this example, we have a

joButton that hides and shows a DOM element:

// you can use other things though

var y = new joExpando([

new joButton("More..."),

joDOM.get("someelementid")

]);

Extends:

joContainer

Methods:

open()

close()

toggle()

Events:

openEvent

closeEvent

joExpandoContent

New widget to contain expando contents. This is normally used with joExpando, but not required.

Extends:


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joContainer

joExpandoTitleCommon UI element to trigger a joExpando. Contains a stylable arrow image which indicates

open/closed state.

Extends:

joControl

Use:

See joExpando use.

joFlexrow

Uses the flexible box model in CSS to stretch elements evenly across a row.

Use:

// a simple row of things

var x = new joFlexrow([

new joButton("OK"),

new joButton("Cancel")

]);

// making a control stretch

var y = new joFlexrow(new joInput("Bob"));

Extends:

joContainer

joFlexcol

Uses the flexible box model in CSS to stretch elements evenly across a column.


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Use:

// fill up a vertical space with things

var x = new joFlexcol([

new joNavbar(),

new joStackScroller()

]);

Extends:

joContainer

joFocus

Singleton which manages global input and event focus among joControl objects.

Methods:

set(joControl)

Unsets focus on the last control, and sets focus on the control passed in.

clear()

Unsets focus on the last control.

refresh()

Sets focus back to the last control that was focused.

joFooterAttempt to make a filler object which pushed subsequent joView objects further down in the

container if possible (to attach its contents to the bottom of a card, for eaxmple).

This behavior requires a working box model to attach properly to the bottom of your container

view.“ „


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Extends:

joContainer

joGesture

Experimental global gesture handler (keyboard, dpad, back, home, flick?). This needs a lot more

fleshing out, so it's not (quite) ready for general consumption.

Events:

upEvent

downEvent

leftEvent

rightEvent

backEvent

forwardEvent

homeEvent

closeEvent

activateEvent

deactivateEvent

joGroupGroup of controls, purely visual.

Extends:

joContainer

joHTML

Note that the events setup here are for the browser or webOS. The setEvents method most

likely needs to change based on which OS you're running, although looking more deeply into

PhoneGap event layer.“ „


47 of 70 05/01/2011 11:54 PM



A simple HTML content control. One interesting feature is it intercepts all <a> tag interactions and

fires off a selectEvent with the contents of the tag's href property.

This is a relatively lightweight approach to displaying arbitrary HTML data inside your app, but it

is not recommended you allow external JavaScript inside the HTML chunk in question.

Also keep in mind that your app document already has <html>, <head> and <body> tags. When

you use the setData() method on this view, make sure you don't use any of these tags to avoid weird

issues.

Extends:

joControl

Use:

// simple html string

var x = new joHTML("<h1>Hello World!</h1><p>Sup?</p>");

// use a joDataSource like a file loader

var y = new joHTML(new joFileSource("sample.html"));

joInput

Single-line text input control. When you instantiate or use setData(), you can either pass in aninitial value or a reference to a joDataSource object which it, like other joControl instances, will bind

to.

Use:

// simple value, simple field

var x = new joInput(a);

// set up a simple joRecord instance with some default data

var pref = new joRecord({

In a future version, it is feasible to load in stylesheets references in the HTML document's

<head> section. For now, that entire can of worms will be avoided, and it's left up to you,the developer, to load in any required CSS files using joDOM.loadCSS().“ „


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username: "Bob",

password: "password"

});

// attach the value to a data structure property

var y = new joInput(pref.link("username"));

Extends:

joControl

Methods:

focus()

blur()

You can manually set focus or call the blur() method (which also triggers a data

save).

setData()

Pass in either some arbitrary value for the control, or a reference to a joDataSource if

you want to automatically bind to a storage system (e.g. joPreference).

joInterface

EXPERIMENTAL

This class parses the DOM tree for a given element and attempts to attach appropriate joView

subclasses to all the relevant HTML nodes. Returns an object with references to all elements with

the id attribute set. This method helps turn HTML into HTML + JavaScript.

Use:

// an HTML element by its ID

This utility method is experimental! Be very careful with it. NOTE that for now, this class

requires you to remove whitespace in your HTML. If you don't know a good approach offhand

to do that, then this thing probably isn't ready for you yet.“ „


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var x = new joInterface("someid");

// a known HTML element

var y = new joInterface(someHTMLElement);

// the entire document body (careful, see below)

var z = new joInterface();

Returns:

A new object with a property for each element ID found. For example:



<jocard id="login">

<jotitle>Login</jotitle>

<jogroup>

<jolabel>Username</jolabel>

<input id="username" type="text">

<jolabel>Password</jolabel>

<input id="password" type="password">

</jogroup>

<jobutton id="loginbutton">Login</jobutton>

</jocard>

Parsed with this JavaScript:

// walk the DOM, find nodes, create controls for each

var x = new joInterface("login");

Produces these properties:

x.login is a reference to a new joCard

x.username is a reference to a new joInput

x.password is a reference to a new joPassword

x.loginbutton is a reference to a new joButton

This in essence flattens your UI to a single set of properties you can use to access the controls that

were created from your DOM structure.

In addition, any unrecognized tags which have an id attribute set will also be loaded into the

properties.

Parsing complex trees:


50 of 70 05/01/2011 11:54 PM

Yes, you can make a joInterface that encapsulates your entire UI with HTML. This is not

recommended for larger or more complex applications, some reasons being:

Rendering speed: if you're defining multiple views within a <jostack> (or another

subclass of joContainer), your users will see a flicker and longer load time while the

window renders your static tags and the extra views for the stack are removed from

view.

Double rendering: again with <jostack> tags, you're going to see a separate render

when the first view is redrawn (has to).

Load time: especially if you're doing a mobile app, this could be a biggie. You are

almost always going to be better off building the app controls with JavaScript

(especially in conjunction with joCache, which only creates DOM nodes for a given

view structure on demand).

If you really want to use HTML as your primary means of defining your UI, you're better off

putting your major UI components inside of a <div> (or other tag) with display: none set in its

CSS property. Like this:



<div class="hideui" id="cards"><jocard id="about">

<jotitle>About this app</jotitle>

<johtml>

This is my app, it is cool.

</johtml>

<jobutton>Done</jobutton>

</jocard>

<jocard id="login">

... etc ...

</jocard>

</div>

Then in your JavaScript:

// pull in all our card views from HTML

var cards = new joInterface("cards");

Definitely use this class judiciously or you'll end up doing a lot of recatoring as your application

grows.

Flattening UI widget references:


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This is both good and bad, depending on your coding style and complexity of your app. Because

all the tags with an ID attribute (regardless of where they are in your tag tree) get a single

corresponding property reference, things could get very messy in larger apps. Again, be smart.

joLabel

Label view, purely a visual presentation. Usually placed in front of input fields and other controls.

Extends:

joView

joList

A widget class which expects an array of any data type and renders the array as a list. The list

control handles DOM interactions with only a single touch event to determine which item was

selected.

Extends:

joControl

Events:

selectEvent

Fired when an item is selected from the list. The data in the call is the index of the

item selected.

changeEvent

Fired when the data is changed for the list.

Methods:

formatItem(data, index)

When subclassing or augmenting, this is the method responsible for rendering a list

item's data.


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compareItems(a, b)

For sorting purposes, this method is called and should be overriden to support

custom data types.

// general logic and approriate return values

if (a > b)

return 1;

else if (a == b)

return 0;

else

return -1

setIndex(index)

getIndex()

DEPRECATED USe setValue() and getValue() instead, see joControl.

refresh()

setDefault(message)

Will present this message (HTML string) when the list is empty. Normally the list isempty; this is a convenience for "zero state" UI requirements.

getNodeData(index)

getLength()

next()

prev()

setAutoSort(boolean)

joMenu

Simple menu class with optional icons.

Extends:

joList


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Methods:

setData(menudata)

See the example below for the format of the menu data.

Use:

// simple inline menu; you can always setup the menu items (or change

// them) but using the `setData()` method, same as any joView

var menu = new joMenu([

{ title: "About" },

{ title: "Frequently Asked Questions", id: "faq" },

{ title: "Visit our website", id: "visit", icon: "images/web" }

]);

// simple inline function event handler

menu.selectEvent.subscribe(function(id) {

switch (id) {

case "0":

// the "About" line; if no id, the index of the menu item is used

stack.push(aboutCard);

break;

case "faq":

stack.push(faqCard);

break;

case "visit":

stack.push(visitCard);

break;

}

});

Advanced Use:

This could actually be called "more consistent and simple" use. If your menus are static, you couldalways setup an id-based dispatch delegate which pushes the appropriate card based on the menu

id selected.

You could use the id in conjunction with view keys you create with joCache. The handler would

then be something like:

menu.selectEvent.subscribe(function(id) {

mystack.push(joCache.get(id));

});


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joNavbar

Floating navigation control. Usually tied to a joStack or joStackScroller. Will handle display of a

"back" button (controllable in CSS) and show the title string of the current view in a stack (if it

exists).

Use:

// make a stack

var stack = new joStackScroller();

// new navbar

var x = new joNavbar();

// link to a stack

x.setStack(stack);

Methods:

back()

Signals the associated stack to move back in its stack (i.e. calls the stack's pop()

method).

setStack(joStack or joStackScroller)

Links this control to a stack.

joBackButton

A "back" button, which can be made to be shown only in appropriate platforms (e.g. iOS, Safari,

Chrome) through CSS styling.

See joNavbar for more information.

Extends:

joButton


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joOption

This controls lets the user select one of a few options. Basically, this is a menu with a horizontal

layout (depending on your CSS).

Use:

// simple set of options

var x = new joOption([

"Red",

"Blue",

"Green"

]);

// set the current value

x.setValue(2);

// or, associate the value with a joRecord property

var pref = new joRecord();

var y = new joOption([

"Orange",

"Banana",

"Grape",

"Lime"

], pref.link("fruit"));

// you can even associate the list with a datasource

var fruits = new joDataSource( ... some query stuff ...);

var z = new joOption(fruits, pref.link("fruit"));

Extends:

joMenu

joPasswordInput

Secret data input field (e.g. displays ****** instead of secret).

Extends:


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joInput

joPopup

A simple popup control. Pass in the UI contents as you would any other subclass of joContainer

(e.g. joCard).

Methods:

show()

hide()

These do what you'd expect.

Extends:

joContainer

Events:

showEvent

hideEvent

joScreenAbstraction layer for the device screen. Uses document.body as its DOM element and allows other

controls to be nested within (usually a joStack or other high-level containers or controls).

Methods:

alert(title, message, buttons)

Simple alert box. The buttons parameter is optional; a simple "OK" button is added

if nothing is specified.

Note that this requires CSS3 which is known not to be currently supported in Opera or

Internet Explorer.“ „


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showPopup(joView)

hidePopup(joView)

These methods allow you to do a completely custom modal joPopup. Pass in either a

joView, an array of them, or and HTMLElement or a string, the same as you would

when you create a joCard or other child of joContainer.

Extends:

joContainer

Use:

var x = new joScreen([

new joNav(),

new joStack(),

new joToolbar()

]);

// show a simple alert dialog

x.alert("Hello", "This is an alert");

// a more complex alert

x.alert("Hola", "Do you like this alert?", [

{ label: "Yes", action: yesFunction, context: this },

{ label: "No", action: noFunction, context: this }

]);

// a completely custom popup

x.showPopup(myView);

Events:

resizeEvent

menuEvent

activateEvent

deactivateEvent

backEvent

forwardEvent

joScroller


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A scroller container. Ultimately, mobile webkit implementations should properly support scrolling

elements that have the CSS overflow property set to scroll or auto. Why don't they, anyway?

Until some sanity is adopted, we need to handle this scrolling issue ourselves. joScroller expects asingle child to manage scrolling for.

Use:

// make a scroller and set its child later

var x = new joScroller();

x.setData(myCard);

// or define things inline, not always a good idea

var y = new joScroller(new joList(mydata));

// you can dump a big hunk of HTML in there, too

// since jo wraps strings in a container element, this works

var z = new joScroller('Some giant HTML as a string');

Extends:

joContainer

Methods:

scrollBy(position)

scrollTo(position or joView or HTMLElement)

Scrolls to the position or the view or element. If you specify an element or view,

make sure that element is a child node, or you'll get interesting results.

setScroll(horizontal, vertical)

Tells this scroller to allow scrolling the vertical, horizontal, both or none.

// free scroller z.setScroll(true, true);

// horizontal z.setScroll(true, false);

// no scrolling z.setScroll(false, false);

joSelect


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Multi-select control which presents a set of options for the user to choose from.

Methods:

setValue(value)

Set the current value, based on the index for the option list.

getValue()

Returns the index of the current selected item.

Extends:

joExpando

Consumes:

joSelectTitle

joSelectList

Properties:

field

Reference to the value field for this control.

list

Reference to the joSelectList for this control.

Use:

// pass in an array of options

var x = new joSelect([ "Apples", "Oranges", "Grapes" ]);

// pass in a current value

var y = new joSelect([ "Apples", "Oranges", "Grapes" ], 2);

// respond to the change event

y.changeEvent = function(value, list) {

console.log("Fruit: " + list.getNodeValue(value));

});


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joSelectTitle

joSelect flavor of joExpandoTitle.

Extends:

joExpandoTitle

joSelectList

A selection list of options used by joSelect.

Extends:

joList

joShim

A simple screen dimmer. Used mostly for popups and other modal use cases.

Methods:

show()

hide()

These do what you'd expect.

Extends:

joView

Events:

showEvent

hideEvent


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joSlider

Slider control, horizontal presentation (may be extended later to allow for vertical and x/y).

Extends:

joControl

Methods:

setRange(min, max, snap)

Where min/max is a number, either integer or decimal, doesn't matter. If max and min are integers,

then snap defaults to 1, otherwise it is set to 0 (no snap, which allows free movement).

The optional snap value adjusts the granularuty of choices. Set to 0 for free-floating, or any other

positive number. Any snap that is less than 0 or greater than the total range of possible values will

be ignored.

Use:

// basic slider, will allow any decimal value

// between 0 and 1, defaults to 0

var x = new joSlider();

// custom range and default value set

var y = new joSlider(0).setRange(-10, 10);

// percent slider, with 5% snap

var z = new joSlider(0).setRange(0, 100, 5);

// responding to change events

var r = new joSlider().changEvent.subscribe(function(value) {

console.log(value);

}, this);

joSound

Play preloaded sound effects using the HTML5 Audio object. This module could be wildly

different for various platforms. Be warned.


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Methods:

play()

pause()

rewind()

stop()

Basic sound controls.

setLoop(n)

Tell the joSound to automatically loop n times. Set to -1 to loop continuously until

pause().

setVolume(level)

Level is a decimal value from 0 to 1. So, half volume would be 0.5.

Events:

endedEvent

errorEvent

joStack

A UI container which keeps an array of views which can be pushed and popped.

The DOM elements for a given view are removed from the DOM tree when popped so we keep the

render tree clean.

Extends:

joView

Methods:

push(joView | HTMLElement)

Pushes a new joView (or HTMLELement) onto the stack.


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pop()

Pulls the current view off the stack and goes back to the previous view.

home()

Return to the first view, pop everything else off the stack.

show()

hide()

Controls the visibility of the entire stack.

forward()

back()

Much like your browser forward and back buttons, only for the stack.

setLocked(boolean)

The setLocked() method tells the stack to keep the first view pushed onto the stack

set; that is, pop() won't remove it. Most apps will probably use this, so setting it as a

default for now.

Events:

showEvent

hideEvent

homeEvent

pushEvent

popEvent

Notes:

Should set classNames to new/old views to allow for CSS transitions to be set (swiping in/out,

cross fading, etc). Currently, it does none of this.

Also, some weirdness with the new forward() and back() methods in conjuction with push() --

need to work on that, or just have your app rigged to pop() on back to keep the nesting simple.


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joStackScroller

What happens when you mix joStack and joScroller? You get this class. Use exactly as you would

joStack, only it automatically puts a scroller in the stack as needed. At some point, this might get

folded into joStack, but for now it's a special class.

It also handles the scrollTo() and scrollBy() methods from joScroller.

Extends:

joStack joScroller

joTabBar

Tab bar widget.

Extends:

joList

Model:

Data is expected to be an array of { type: "", label: ""} objects, in the display order for the

bar.

joTableTable control, purely visual representation of tabular data (usually an array of arrays).

Use:

// simple table with inline data

var x = new joTable([

["Nickname", "Phone", "Email"],

["Bob", "555-1234", "[email protected]"],

["Jo", "555-3456", "[email protected]"],


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["Jane", "555-6789", "[email protected]"]

]);

// we can respond to touch events in the table

x.selectEvent.subscribe(function(index, table) {

// get the current row and column

joLog("Table cell clicked:", table.getRow(), table.getCol());

// you can also get at the cell HTML element as well

joDOM.setStyle(table.getNode(), { fontWeight: "bold" });

});

Extends:

joList

Methods:

setCell(row, column)

Sets the active cell for the table, also makes it editiable and sets focus.

getRow(), getCol()

Return the current row or column

joTextarea

Multi-line text input control. When you instantiate or use setData(), you can either pass in an

initial value or a reference to a joDataSource object which it, like other joControl instances, will bind

to.

Basically, this is just a multi-line version of joInput.

Use:

// simple multi-line field

var sample = "This is some sample text to edit.";

var x = new joTextarea(sample);

// setting the style inline using chaining

var f = new joTextarea(sample).setStyle({

minHeight: "100px",


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maxHeight: "300px"

});

// adding a simple change event handler using chaining

var h = new joTextarea(sample).changeEvent.subscribe(function(data) {

joLog("text area changed:", data);

});

// attach the value to a preference

var y = new joTextarea(joPreference.bind("username"));

// attach input control to a custom joDataSource

var username = new joDataSource("bob");

var z = new joTextarea(username);

Extends:

joInput

joTitle

Title view, purely a visual presentation.

Extends:

joContainer

joToggle

Boolean widget (on or off).

Methods:

setLabels(Array)

You can change the labels for this control, which default to "Off" and "On".

Extends:

joControl


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Use:

// simple

var x = new joToggle();

// with value

var y = new joToggle(true);

// with custom labels

var z = new joToggle().setLabels(["No", "Yes"]);

See Data Driven Controls for more examples.

joToolbar

Locks UI controls to the bottom of whatever you put this container into.

Extends:

joContainer

joView

Base class for all other views, containers, controls and other visual doo-dads.

Use:

var x = new joView(data);

Where data is either a text or HTML string, an HTMLElement, or any joView object or subclass.

Methods:

setData(data)

getData()

createContainer(type, classname)

setContainer(HTMLElement)

getContainer()


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clear()

refresh()

attach(HTMLElement or joView)

detach(HTMLElement or joView)

Convenience methods which allow you to append a view or DOM node to the

current view (or detach it).


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Index


jo documentaion

Documents