web development with lua @ bulgaria web summit 2016

Web development with Lua Programming Language

Introducing Sailor, an MVC web framework in Lua

Etiene Dalcol @etiene_d

@etiene_dBulgaria Web Summit 2016

@etiene_d


Sailor!sailorproject.org

http://sailorproject.org


Google Summer of Code

LabLua


Lua Ladieslualadies.org


Lua Space

lua.space

@space_lua


Lua overview

The state of web dev

Sailor


• Script Language • Duck-typed • Multi-paradigm

• procedural, OO, functional,data-description

• Garbage collection • Coroutines • First-class functions • Lexical scoping • Proper tail calls • MIT License

What is Lua?


Advantages

Powerful.


Why Lua?Size

(docs included)

First-class functions+

Lexical scoping +

Metatables

Native C API

276 Kb

Object Orientation

Ada, Fortran, Java, Smalltalk, C#, Perl,

Ruby etc.+


Advantages

Simple.Powerful.


_G _VERSION assert collectgarbage dofile error getmetatable ipairs load loadfile next pairs pcall print rawequal rawget rawlen rawset require select setmetatable tonumber tostring type xpcall bit32.arshift bit32.band bit32.bnot bit32.bor bit32.btest bit32.bxor bit32.extract bit32.lrotate bit32.lshift bit32.replace bit32.rrotate bit32.rshift

coroutine.create coroutine.resume coroutine.running coroutine.status coroutine.wrap coroutine.yield debug.debug debug.getuservalue debug.gethook debug.getinfo debug.getlocal debug.getmetatable debug.getregistry debug.getupvalue debug.setuservalue debug.sethook debug.setlocal debug.setmetatable debug.setupvalue debug.traceback debug.upvalueid debug.upvaluejoin io.close io.flush io.input io.lines io.open io.output io.popen io.read io.stderr io.stdin io.stdout io.tmpfile io.type io.write

file:close file:flush file:lines file:read file:seek file:setvbuf file:write math.abs math.acos math.asin math.atan math.atan2 math.ceil math.cos math.cosh math.deg math.exp math.floor math.fmod math.frexp math.huge math.ldexp math.log math.max math.min math.modf math.pi math.pow math.rad math.random math.randomseed math.sin math.sinh math.sqrt math.tan math.tanh

os.clock os.date os.difftime os.execute os.exit os.getenv os.remove os.rename os.setlocale os.time os.tmpname package package.config package.cpath package.loaded package.loadlib package.path package.preload package.searchers package.searchpath string.byte string.char string.dump string.find string.format string.gmatch string.gsub string.len string.lower string.match string.rep string.reverse string.sub string.upper table.concat table.insert table.pack table.remove table.sort table.unpack


"Since Lua itself is so simple, it tends to

encourage you to solve problems simply."

Ragnar Svensson - Lead Developer at King (Lua Workshop Oct 15 2015)


Advantages

Fast.Simple.Powerful.


http://www.humbedooh.com/presentations/ACNA%20-%20mod_lua.odp Introducing mod_lua by Daniel Gruno

http://www.humbedooh.com/presentations/ACNA%20-%20mod_lua.odp


Better Reasons

• It looks cool (I heard you could make games with it)

My


Better Reasons



Better Reasons


• It’s made in my home country (In my university to be more precise)



• It’s made in my home country (In my university to be more precise)

• It’s easy to learn

Better Reasons


-- Cipher module

--[[ Based on algorithms/caesar_cipher.lua

by Roland Yonaba ]]

local cipher = {}

local function ascii_base(s)

return s:lower() == s and ('a'):byte() or ('A'):byte()

end

function cipher.caesar( str, key )

return str:gsub('%a', function(s)

local base = ascii_base(s)

return string.char(((s:byte() - base + key) % 26) + base)

end)

end

return cipher

One slide crash course: cipher module


-- Cipher module


by Roland Yonaba ]]

local cipher = {}



end





end)

end

return cipher


private

public


-- Cipher module


by Roland Yonaba ]]

local cipher = {}



end





end)

end

return cipher



?

?

Learning Lua

?

? ?


Lua on the web

• Early stage

• cgilua ~ 1995

• Kepler Project ~ 2003


“ I have myself developed Web sites with pure C++, Java, C#, PHP, and Python. The easiest way to go was definitely Python. If the libraries existed, Lua would be not quite as easy to use as Python, but probably quite a bit more efficient; I think it would become my first choice... if the libraries existed.” Michael Gogins

“ Recently there was some discussion about mod_lua on the Apache developers mailing list. I mentioned there that I feel Lua could replace PHP as the number one web scripting language if mod_lua were stable (i.e. not still in beta) and it were implemented well (not making some of PHP's mistakes such as putting everything in the global scope with no consistent naming or parameter schemes). I've wanted to use Lua for all the things I currently use PHP for ever since I discovered it.” Rena


9423 words

http://eev.ee/blog/2012/04/09/php-a-fractal-of-bad-design/


http://w3techs.com/technologies/history_overview/programming_language/ms/y

http://w3techs.com/technologies/history_overview/programming_language/ms/y


Why?


Why?

http://blog.codinghorror.com/php-sucks-but-it-doesnt-matter/


Servers

• Apache: mod_lua

• Nginx: OpenResty


Servers

• Apache: mod_lua

• Nginx: OpenResty

• Xavante

• Others: Lighttpd, Lwan, Pegasus, Mongoose


Frameworks

Orbit (2007) Least known No significant updates since 2010 MVC


Frameworks

Orbit (2007) Least known No significant updates since 2010 MVC

Luvit (2011) Most popular Intense development node.js port 2-4x faster Needs a better documentation


Frameworks

Lapis (2012) Intense development Moonscript and Lua Very well documented Templater OpenResty only Not MVC


Frameworks

Lapis (2012) Intense development Moonscript and Lua Very well documented Templater OpenResty only Not MVC

Others Very early development, complicated, abandoned, poorly documented, license issues or I never heard about it...

lua.space/webdev/the-best-lua-web-frameworks


Sailor!sailorproject.org



Sailor!


Sailor!

0.1 (Venus)


Sailor!

0.1 (Venus)

0.2 (Mars)


What exactly is Sailor?

• It’s an MVC web framework • Completely written in Lua • Compatible with Apache (mod_lua), Nginx (OpenResty),

Xavante, Mongoose, Lighttpd and Lwan • Compatible with Linux, Windows and Mac • Compatible with different databases • MIT License • Pre alpha v0.5 (Pluto) • Planning next release to be a 1.0!


What (else) is cool about Sailor?

• Routing and friendly URLs • Session, cookies, include, redirect… • Lua Pages parsing • Mail sending • Simple Object Relational-Mapping • Validation (valua) • Basic login and authentication modules • Form generation • Themes (Bootstrap integration out of the box) • App generator (Linux and Mac only) • Model and CRUD generator • Automated tests


• Routing and friendly URLs • Session, cookies, include, redirect… • Lua Pages parsing • Mail sending • Simple Object Relational-Mapping • Validation (valua) • Basic login and authentication modules • Form generation • Themes (Bootstrap integration out of the box) • App generator (Linux and Mac only) • Model and CRUD generator • Automated tests

• Lua at client

What (else) is cool about Sailor?


Not so great things

• It’s still in early development • Things are changing fast • It lacks features • Documentation


How to get Sailor!

$ luarocks install sailor $ sailor create ‘My App’ /var/www $ cd /var/www/my_app $ lua start-server.lua


/conf /controllers /models /pub /runtime /tests /themes /views

App structure


/conf /controllers /models /pub /runtime /tests /themes /views

App structure

Lua filesStuff!

JS libraries, images…Temp files Lua Pages


Example!

-- /controllers/site.lua local site = {} function site.index(page) local msg = “Hello World” page:render(‘index’, { msg = msg } ) end function site.notindex(page) page.theme = nil page:write(“I’m different!”) end return site

<!-- /views/site/index.lp —> <p> A message from the server: <?lua page:print(msg) ?> <br/> The message again: <%= msg %> <!-- syntactic sugar: same thing as above —></p>

Example!


<?lua@server -- Code here runs on the server ?> <?lua -- Same as above ?> <?lua@client -- Runs at the client ?> <?lua@both -- Runs at the server and the client ?> <?lua@both another_msg = “Another message” ?> <?lua page:print(another_msg) ?> <?lua@client window:alert(another_msg) ?>

Example!


local user = {} local v = require “valua” -- validation module user.attributes = { { id = “safe” }, { name = v:new().not_empty().len(6,50) } } user.db = { key = ‘id’, table = ‘users’ } user.relations = { posts = { -- u.posts relation = “HAS_MANY”, model = “post”, attribute = “author_id” } } return user

Example!


bit.ly/luawebdev

http://bit.ly/luawebdev


Rails Girls Summer of Code

railsgirlssummerofcode.org

http://railsgirlssummerofcode.org

sailorproject.org

github.com/sailorproject

[email protected]

@etiene_d


http://github.com/Etiene/sailor

mailto:[email protected]

sailorproject.org


[email protected]

@etiene_d

gitter.im/sailorproject/sailor

@sailor_lua




Thank you!sailorproject.org


[email protected]

@etiene_d




web development with lua @ bulgaria web summit 2016

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