crud presentation

8/14/2019 CRUD presentation

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CRUDNow This App Is Totally FUCD


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CRUD is a way ofthinking.


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Create

ReadUpdate

Delete


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The Seven CRUD

Methods

deflist; end

defshow; enddefnew; enddefcreate; enddefedit; end

defupdate; enddefdestroy; end

# Show all items

# Show a specific item# Form for creating new item# Create new item# Form for editing new item

# Update and existing item# Destroy an existing item


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Those are your verbs.Welcome to a world of

nouns.


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Get every controller tomatch those methods,

and youre done.


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OK, Maybe not all willmatch. Some things justcant be CRUDy well.


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Making CRUDFrom the Ground On Up


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Show and Make Thingsdefindex @things = Thing.find_allend

defnew @thing = Thing.newend

defcreate @thing = Thing.create(params[:thing]) redirect_to:action => :indexend


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index.rhtml thing, :collection => @things %>

new.rhtml { :action => :create } do %>

Name:


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edit.rhtml { :action => :update} do %>Name:


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Get Rid of Things

defdestroy

@thing = Thing.find(params[:id]) @thing.destroyredirect_to:action => :index

end


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This is Basic Rails


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Next is Where ThingsStart To Get Messy


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Adding Categoriesclass Thing < ActiveRecord::Base has_and_belongs_to_many:categories

end

class Category < ActiveRecord::Base has_and_belongs_to_many:thingsend


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How Do We Add Thingsto Categories?


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Put It In ThingsController!defadd_to_category @thing = Thing.find(params[:thing_id]) @category = Category.find(params[:category_id]) @thing.categories :indexend

defremove_from_category

@thing = Thing.find(params[:id]) @category = Category.find(params[:category_id]) @thing.delete(@category) redirect_to:action => :indexend


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This Is Not CRUD!


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Instead of shoehorningthis in, try to ensureyour app is CRUD.


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CRUD Tip #1Many-to-Many Associations need CRUD and new

models.


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Again, with CRUDclass Thing < ActiveRecord::Base has_many:categorizationshas_many:categories, :through => :categorizations

end

class Category < ActiveRecord::Base has_many:categorizationshas_many:things, :through => :categorizations

end

class Categorization < ActiveRecord::Base belongs_to:thing belongs_to:category

end


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The Controllerclass CategorizationsController < ApplicationControllerdefcreate

@categorization = Categorization.create(params[:categorization] )

redirect_to:controller => things, :action => indexend

defdestroy

@categorization = Categorization.find(params[:id]) @categorization.destroyredirect_to:controller => things, :action => index

endend


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Whats the big deal?

These are basically thesame methods in a

different place!


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FALSE!


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The new methods arecleaner.


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The architecture iseasier to read.


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The association cannow have meaningful

properties.


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OK, associations are aprime place for CRUD.Is that all it helps with?


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Take a look at AJAX.


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Creating with AJAX

defcreate_with_ajax


end


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Weve Seen This Beforedefcreate

@categorization = Categorization.create(

params[:categorization] ) redirect_to:controller => things, :action => indexend

defcreate_with_ajax


end


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Duplication is bad, mkay.


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So, lets get back toCRUD.


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Now With respond_to

defcreate @categorization = Categorization.create(params[:categorization] )

respond_to do |type|type.html { redirect_to:controller => things , :action => index }type.js { render }

end

end


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CRUD Tip #2Use respond_to for controlling view selection.


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CRUD help anywhereelse?


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Lets add users and thensee.


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AccountController

deflogin; enddeflogout; end

defsignup; enddefedit; end

# CREATE a login# DESTROY a login

# CREATE a user# UPDATE a user

The comments say it all.


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CRUD Tip #3Events are a great place to insert CRUD.


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LoginControllerdefcreate @login=Login.create(params[:login])end

defdestroy @login = Login.find(params[:id]) @login.destroy

end


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The Modelsclass Event < ActiveRecord::Baseend

class Login < Event belongs_to:userend

class User < ActiveRecord::Base has_many :loginsend


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Hey Idiot, I just made amodel for Logins. Argh,

CRUD wastes time!


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Actually, look at whatyoure now able to do.


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LoginController

separates concept oflogging in from User

management.


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Login model allows usto track the users logins

over time.


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Modeling events givesyou information about

user behavior.


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Knowing your usersmakes you money!


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Going from RPC to REST, I cut

the total number of actions byalmost twenty.- Scott Raymond, IconBuffet


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CRUD saves youmoney!


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Its got other benefits,too.


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simply_restfulA plugin for implementing verb oriented controllers.


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Current URLs

deflist; end



# GET things/list

# GET things/show/1# GET things/new# POST things/create# GET things/edit/1

# POST things/update/1# POST things/destroy/1


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simply_restful URLs

deflist; end



# GET things

# GET things/1# GET things;new# POST things# GET things/1;edit

# PUT things/1# DELETE things/1


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Who cares? Its just aURL.


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Its prettier.

(And it makes betteruse of HTTP)


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It gives youActiveResource!


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ActiveResource is aneasy to use API in

development by DHH.Look at the source code or DHHs presentation tolearn more.


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Recap


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CRUD is an

architecture that helpsyou organize your code

and remove obfuscation.


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CRUD helps you makemoney!


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Other Resources

DHHs presentation: www.loudthinking.com/lt-files/worldofresources.pdf Scott Raymonds blog: scottraymond.net/ Ryan Daigles article: www.ryandaigle.com/articles/

2006/06/30/whats-new-in-edge-rails-activeresource-is-

here

crud presentation

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