angular-yii2-model

A simple and lightweight AngularJS 1.x service designed to consume Yii2 RESTful API framework and its built-in HATEOAS.

Installation

- Install via bower: bower install --save angular-yii2-model
- or via npm: npm install --save angular-yii2-model
- or by manually downloading the zip file and including either dist/angular-yii2-model.js or dist/angular-yii2-model.min.js to your HTML script tags.

Configurations

#### Client:
``javascript
// Add it as a dependency to your app
angular.module('your-app', ['angular-yii2-model']);

// Configure its provider to define the base url to your Yii2 RESTful API
angular.module('your-app').config(['YiiModelProvider', function(YiiModelProvider) {
YiiModelProvider.baseUrl = 'http://localhost/server/api';
}]);

`
#### Server:
You don't need to enable any data serializing when using this extension as those data are already provided by Yii within the response headers. So I'd prefer to save my bandwidth transfer rate and parse the headers. The only change that you may have to do is to ensure that those headers are exposed to the browser when implementing the CORS filter within an Access-Control-Expose-Headers tag. The following is a controller example that I've been using when building this extension:

`php
namespace app\controllers;

class UserController extends \yii\rest\ActiveController
{
public $modelClass = 'app\models\User';

public function behaviors()
{
$behaviors = parent::behaviors();
unset($behaviors['authenticator']);

// CORS filter
$behaviors['corsFilter'] = [
'class' => \yii\filters\Cors::className(),
'cors' => [
'Origin' => ['*'],
'Access-Control-Request-Method'=>['GET','POST','PUT','PATCH','DELETE','HEAD','OPTIONS'],
'Access-Control-Allow-Credentials' => true,
'Access-Control-Expose-Headers' => [
// Calulated hyperlinks
'Link',
// Pagination
'X-Pagination-Current-Page',
'X-Pagination-Page-Count',
'X-Pagination-Per-Page',
'X-Pagination-Total-Count'
],
],
];

// Authentication filter
$behaviors['authenticator'] = [
'class' => \yii\filters\auth\HttpBearerAuth::className(),
'except' => ['options'],
],

return $behaviors;
}
}
`




Usage


This is an example using the resolve method of angular-ui-router library to load a collection, a resource and an empty instance to use with new creations:
`javascript
.state('form', {
url: '/form',
controllerAs: '$',
controller: 'FormCtrl',
templateUrl: 'form.html',
resolve: {


allUsers: function(YiiModel) {
/*
* Load a collection of 10 users. we need their 'id' and 'username' fields only.
* The request to achieve: GET /users?fields=id,username&page=1&per-page=10
**/
var users = YiiModel.all('users');
users.$select(['id','username']); // accepts a string or an array of strings. optional and can be used with both resources and collections.
return users.$load(10); // returns a promise. required to emit the request that gets the collection.
},


UserNumberOne: function(YiiModel) {
/*
* Load the user resource whose ID is 1. we also need to load his 'profile'.
* The request to achieve: GET /users/1?expand=profile
**/
var user = YiiModel.one('users');
user.$with('profile'); // accepts a string or an array of strings. optional and can be used with both resources and collections.
return user.$find(1); // returns a promise. required to emit the request that gets the resource.
},


newUser: function(YiiModel) {
/*
* Just an empty instance of user so we can POST it later to server.
**/
return YiiModel.one('users');
},


}
});
`

Then, they should be passed to some controller where they could be used or injected to some view's scope:

`javascript
angular.module('your-app').controller('FormCtrl',function($scope,allUsers,UserNumberOne,newUser){
var $ = this;
$.allUsers = allUsers;
$.userNumberOne = UserNumberOne;
$.newUser = newUser;
});
`
Alternatively; if not using ui-router; both $load() and $find() methods should return a $http promise and could be used as follow:

`javascript
angular.module('your-app').controller('FormCtrl', function($scope, YiiModel) {
var $ = this;

var users = YiiModel.one('users');
users.$select(['id','username']);
users.$load(10).then(function(data){
$.allUsers = data;
});

});
`

$3


`javascript
$.allUsers.$data // <- here you'll find your data

// clear collection and load the fifth page content.
$.allUsers.$getPage(5)

// load the next page content (page 6).
$.allUsers.$nextPage()

// load the previous page content.
$.allUsers.$prevPage()

// jump to last page.
$.allUsers.$lastPage()

// load first page content.
$.allUsers.$firstPage()

// reload current data from server.
$.allUsers.$refresh()

// returns a boolean. true if current page is first.
$.allUsers.$isFirst()

// returns a boolean. true if current page is the last one.
$.allUsers.$isLast()

// returns a boolean. true if there is a next page.
$.allUsers.$existNext()

// returns a boolean. true if there is a previous page.
$.allUsers.$existPrev()

// reload with extra url params:
// GET /users?fields=id,username&page=1&per-page=10&name=lukaku&club=everton
$.allUsers.$where({name: 'lukaku', club: 'everton'})

// outputs what parsed from the headers meta tags.
$.allUsers.$meta.currentPage // X-Pagination-Current-Page
$.allUsers.$meta.pageCount // X-Pagination-Page-Count
$.allUsers.$meta.perPage // X-Pagination-Per-Page
$.allUsers.$meta.totalCount // X-Pagination-Total-Count
`

$3


`javascript
// change default primary Key attribute. default to 'id'.
$.userNumberOne.$primaryKey = 'user_id';

// returns the primary Key value.
$.userNumberOne.$getPrimaryKey() // outputs 1

// returns a boolean. Either it is a new record or has been loaded from server.
$.userNumberOne.$isNew() // returns false
$.newUser.$isNew() // returns true

// make a delete request: DELETE /users/1
$.userNumberOne.$delete()

// make a PUT request after changing an attribute value: PUT /users/1 {name: 'abc', ...}
$.userNumberOne.name = 'abc';
$.userNumberOne.$update();

// make a POST request to create a new record: POST /users {name: 'xyz'}
$.newUser.name = 'xyz';
$.newUser.$create();

// either update or create depending on model being or not a new record.
// same as: $.newUser.$isNew() ? $.newUser.$create() : $.newUser.$update();
$.newUser.$save();
`




Handling server-side validation

There is always validation cases that client cannot handle like checking if an input value is unique in a database. Of course those could only be handled by server. When Yii rejects an input by throwing a validation fail error (422), this extension will add an $errors attribute to your model where you'll find the field name being rejected, the error message as received from the server and a pattern regex generated by this extension so you can use it to prevent client from re-sending the same input:

`javascript
{
"username": {
"message": "Username \"lukaku\" has already been taken.",
"pattern": "(?!^lukaku$)(^.*$)"
}
}
`

Client in this case doesn't need to understand why server has rejected that input as we can simply use angular's ng-pattern attribute to make it know that whatever input it was, user shouldn't send it again as server won't approve it. Here is a HTML form validation example using angular built-in services while showing any extra error message received from the server and feeding the ng-pattern attribute with our pattern regex to prevent re-sending it again:


`html





Username
type="text"
name="username"
ng-model="$.newUser.username"
ng-pattern="$.newUser.$errors.username.pattern"
ng-minlength="3"
ng-maxlength="8"
required
>

Username is required

too short

too long

{{$.newUser.$errors.username.message}}




Submit




`
Note that you can always check if a model instance is holding any error received from server by calling $.newUser.$hasErrors() which returns a boolean value. Those could also be cleared by calling $.newUser.$clearErrors().

Authentication and custom Headers

This extension has a $setHeaders() method which you can use to define a custom set of headers within a java-script object to be sent with any request of a specific model like the one required for Authentication:


`javascript
resolve: {
allUsers: function(YiiModel) {
var users = YiiModel.all('users');
users.$setHeaders({'Authorization': 'Bearer ' + token });
return users.$load(20);
}
}
`
However nothing is provided by this extension to hold default or global headers for all requests as it is already built on top of angular's http core service which already supports such configurations like setting its $http.defaults.headers property in a run block or using interceptors. More about it here.




Data Filtering

At the time of writing there is no official support to data searching or filtering by Yii2 RESTful API framework as it is yet under discussion here. But implementing data filtering in Yii2 isn't hard. There is many ways to achieve it. One of those is by involving a Search Class like the one generated by the gii module to filter your data:

`php
class UserSearch extends \app\models\User
{
public function rules() ...
public function scenarios() ...

public function search($params, $formName = null)
{
$query = \app\models\User::find();

// add conditions that should always apply here

$dataProvider = new ActiveDataProvider([
'query' => $query,
]);

$this->load($params, $formName);

if (!$this->validate()) {
$query->where('0=1');
return $formName === '' ? $this : $dataProvider;
}
}
}


class UserController extends \yii\rest\ActiveController
{

// ...

public function actions()
{
$actions = parent::actions();

$actions['index'] = [
'class' => 'yii\rest\IndexAction',
'modelClass' => $this->modelClass,
'prepareDataProvider' => function () {
$searchModel = new \app\models\UserSearch();
return $searchModel->search(\Yii::$app->request->queryParams, '');
},
];

return $actions;
}
}
`
(based on klimov-paul 's comment. An alternative but same approach may also be found here)

Once implemented in server-side. The $where() method provided by this extension will help filtering your resources by updating its data array as soon as the new filtered list is received from server. Here is a quick example on how to use it with a search input:

`javascript
type="text"
placeholder="Search by name"
ng-model="query"
ng-change="$.allUsers.$where({name: query});"
ng-model-options="{updateOn:'default blur', debounce:{'default':500, 'blur':0}}"
>


{{ $.allUsers.$data | json}}


``
(note: the debounce trick here is to wait for user stop writing instead of sending new requests on each typing)