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134 lines
5.5 KiB
Text
134 lines
5.5 KiB
Text
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@workInProgress
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@ngdoc overview
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@name Tutorial: Step 2
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@description
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<table id="tutorial_nav">
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<tr>
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<td id="previous_step">{@link tutorial.step_1 Previous}</td>
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<td id="step_result">{@link http://angular.github.com/angular-phonecat/step-2/app Example}</td>
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<td id="tut_home">{@link tutorial Tutorial Home}</td>
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<td id="code_diff">{@link
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https://github.com/angular/angular-phonecat/commit/02e30dd64e0e5554fbf4d442ade5b1a251f2bf56
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Code Diff}</td>
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<td id="next_step">{@link tutorial.step_3 Next}</td>
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</tr>
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</table>
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An important feature of angular is the incorporation of the principles behind {@link
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http://en.wikipedia.org/wiki/Model–View–Controller the MVC design pattern} into client-side web
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apps. With that in mind, let's use a little angular and a little JavaScript to add Model, View,
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and Controller components to our app.
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Our __View__ component is constructed by angular from this template:
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__`app/index.html`:__
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<pre>
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...
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<body ng:controller="PhoneListCtrl">
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<ul>
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<li ng:repeat="phone in phones">
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{{phone.name}}
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<p>{{phone.snippet}}</p>
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</li>
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</ul>
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<script src="lib/angular/angular.js" ng:autobind></script>
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<script src="js/controllers.js"></script>
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</body>
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...
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</pre>
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Our data __Model__ (a small set of phones in object literal notation) is instantiated within our
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__Controller__ function (`PhoneListCtrl`):
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__`app/js/controllers.js`:__
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<pre>
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/* App Controllers */
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function PhoneListCtrl() {
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this.phones = [{"name": "Nexus S",
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"snippet": "Fast just got faster with Nexus S."},
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{"name": "Motorola XOOM™ with Wi-Fi",
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"snippet": "The Next, Next Generation tablet."},
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{"name": "MOTOROLA XOOM™",
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"snippet": "The Next, Next Generation tablet."}];
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}
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</pre>
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The "Angular way" urges us to test as we develop:
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__`test/unit/controllersSpec.js`:__
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<pre>
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/* jasmine specs for controllers go here */
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describe('PhoneCat controllers', function() {
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describe('PhoneListCtrl', function(){
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it('should create "phones" model with 3 phones', function() {
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var ctrl = new PhoneListCtrl();
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expect(ctrl.phones.length).toBe(3);
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});
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});
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});
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</pre>
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## Discussion:
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So what were our changes from Step 1?
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* __View template:__ We replaced the hard-coded phone list with the {@link
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angular.widget.@ng:repeat ng:repeat widget} and two {@link guide.expression angular expressions}
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enclosed in curly braces: `{{phone.name}}` and `{{phone.snippet}}`:
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* The `ng:repeat="phone in phones"` statement in the `<li>` tag is an angular repeater. It
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tells angular to create a `<li>` element for each phone in the phones list, using the first
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`<li>` tag as the template.
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* The curly braces around `phone.name` and `phone.snippet` are an example of {@link
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angular.markup angular markup}. The curly braces are shorthand for the angular directive
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{@link angular.directive.ng:bind ng:bind}. They indicate to angular that these are template
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binding points. Binding points are locations in the template where angular constructs two-way
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data-binding between the View and the Model. In angular, the View is a projection of the Model
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through the HTML template.
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* __Controller:__ At this point, it doesn't appear as if our controller is doing very much
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controlling, but it is playing a crucial role: providing context for our data model so we can
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establish two-way data-binding between the model and the view. Note in the following how we
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connected the dots between our presentation, data, and logic components:
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* The name of our controller function (in the JavaScript file `controllers.js`) matches the
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{@link angular.directive.ng:controller ng:controller} directive in the `<body>` tag
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(`PhoneListCtrl`).
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* We instantiated our data within the scope of our controller function, and our template
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binding points are located within the block bounded by the `<body
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ng:controller="PhoneListCtrl>` tag.
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So, our controller function becomes the {@link angular.scope scope} of our data model.
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Angular uses scopes, along with the information contained in the template, data model, and
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controller to keep the Model and View separated but in sync: any changes to the model are
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reflected in the view; any changes that occur in the view are reflected in the model.
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* __Model:__ For our data model, we created a simple array of phone records, specified in object
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literal notation.
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* __Testing:__ Ease of testing is another cornerstone of angular's design philosophy. All we are
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doing here is showing how easy it is to create a unit test using the technology baked into
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angular. The test verifies that we have some data, and that there are 3 records in the data set.
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Angular's testing stack utilizes Jasmine's Behavior-driven Development (BDD) framework. You
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can learn about it on the {@link http://pivotal.github.com/jasmine/ Jasmine home page} and on
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the {@link https://github.com/pivotal/jasmine/wiki Jasmine wiki}.
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<table id="tutorial_nav">
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<tr>
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|||
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<td id="previous_step">{@link tutorial.step_1 Previous}</td>
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|
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<td id="step_result">{@link http://angular.github.com/angular-phonecat/step-2/app Example}</td>
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|
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<td id="tut_home">{@link tutorial Tutorial Home}</td>
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<td id="code_diff">{@link
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|||
|
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https://github.com/angular/angular-phonecat/commit/02e30dd64e0e5554fbf4d442ade5b1a251f2bf56
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Code Diff}</td>
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<td id="next_step">{@link tutorial.step_3 Next}</td>
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</tr>
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</table>
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