Difference between #35 and #34 of By Example: CHtml

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Title
By Example: CHtml
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Category
Tutorials
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Tags
listData, chtml, link, button
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Content
"By Example" cookbook pages will provide coding examples for many of
the commonly used classes within Yii. We will try to provide as many usage
examples as possible for keep these pages as helpful as possible. 

Smarthead will be pulling these from the forum when he is not finding the
answers on his own. Please request examples using the comments below or ask for
an example in the forum. Thanks.

Avaiable methods:<br>

- [CHtml::link()](#hh0)
- [CHtml::button()](#hh1)
- [CHtml::textField()](#hh2)
- [CHtml::listData()](#hh3)
- [CHtml::dropDownList()](#hh4)

## CHtml::link() method

~~~
[php]
public static string link(string $text, mixed $url='#', array $htmlOptions=array
( ))
~~~
Generates a hyperlink tag.

***

**Example 1: Linking to a controller action**
~~~ 
[php]
<?php echo CHtml::link('Link Text',array('controller/action')); ?>
~~~


**HTML Output:**
~~~
[php]
<a href="index.php?r=controller/action">Link Text</a>
~~~


***

**Example 2: Linking to a controller action with querystring parameters**
~~~
[php]
<?php echo CHtml::link('Link Text',array('controller/action',
                                         'param1'=>'value1')); ?>
~~~

**HTML Output:**

~~~
[php]
<a href="index.php?r=controller/action&param1=value1">Link
Text</a>
~~~

***

**Example 3: Linking to a controller action with multiple querystring
parameters**
~~~
[php]
<?php echo CHtml::link('Link Text',array('controller/action',
                                         'param1'=>'value1',
                                         'param2'=>'value2',
                                         'param3'=>'value3')); ?>
~~~

**HTML Output:**

~~~
[php]
<a
href="index.php?r=controller/action&param1=value1&param2=value2&param3=value3">Link
Text</a>
~~~
   
***

**Example 4: Link opening a new page**
~~~
[php]
<?php echo CHtml::link('Link Text',array('controller/action',
                   'param1'=>'value1'), array('target'=>'_blank'); ?>
~~~

**HTML Output:**

~~~
[php]
<a target="_blank"
href="index.php?r=controller/action&param1=value1">Link
Text</a>
~~~

***

**Example 5: Linking to a controller action inside the actual controller**
(Suppose you are in the PostController/view and wants to link to
PostController/create) 

Just remove the 'controller' part from the string
~~~ 
[php]
<?php echo CHtml::link('Link Text',array('action')); ?>
~~~

If you are linking to an action from another controller, use the syntax of the
former examples.


***

**Example 6: Linking to a controller action from the site root**
(Suppose you are inside a module and wants to make the link from a controller of
the root application) 

In this case, add an slash "/" at the start of the string url
~~~ 
[php]
<?php echo CHtml::link('Link Text',array('/controller/action')); ?>
~~~
This makes more sense if you are working with modules.

***

**Example 7: Linking to a controller action from another module**

Replace below the module-id with desired module id .
~~~ 
[php]
<?php echo CHtml::link('Link Text',array('/module-id/controller/action'));
?>
~~~

***

**Example 8: Linking to a controller action from the same module**

This is useful when you want to make absolute paths avoiding to use static
module names.
~~~ 
[php]
<?php echo CHtml::link('Link
Text',array('/{$this->module->id}/controller/action')); ?>
~~~

***

**Example 9: Linking to a controller action via POST with confirmation dialog**

Delete actions created using gii require the delete request be sent via POST to
help prevent deleting objects by accident. Below is an example how to create a
link that sends the request via POST and also asks for confirmation. Where you
are redirected after the delete depends on your delete action. Note that the
`id` link parameter below is a GET type parameter (submit URL will be something
like `http://example.com/post/delete/id/100`).
~~~ 
[php]
<?php echo CHtml::link('Delete',"#",
array("submit"=>array('delete', 'id'=>$data->ID), 'confirm'
=> 'Are you sure?')); ?>
~~~
If you are using CSRF protection in your application do not forget to add csrf
parameter to the htmlOptions array.
~~~
[php]
<?php echo CHtml::link('Delete',"#",
array("submit"=>array('delete', 'id'=>$data->ID), 'confirm'
=> 'Are you sure?', 'csrf'=>true)); ?>
~~~

***

**Example 10: Linking to a controller action via POST with POST parameters**

If you need to make POST request with arbitary link with additional POST
parameters you should use following code (submit URL will be something like
`http://example.com/blog/deletePost/param/100`).

~~~
[php]
<p><?php echo lnk('Delete blog post', '#', array(
	'submit'=>array('blog/deletePost', 'param'=>100),
	'params'=>array('id'=>$post->id,
'status'=>Post::STATUS_DELETED_BY_OWNER),
	'csrf'=>true,
)); ?></p>
~~~

## CHtml::button() method

~~~
public static string button(string $label='button', array $htmlOptions=array (
))
~~~
Generates a button.

***

**Example 1: Connecting a button to a controller action**
~~~
[php]
<?php echo CHtml::button('Button Text', array('submit' =>
array('controller/action'))); ?>
~~~

**HTML Output:**
~~~
[php]
<input id="yt0" type="button" value="Button
Text" name="yt0"/>
<script type="text/javascript">
/*<![CDATA[*/
jQuery(document).ready(function() {
             jQuery('#yt0').click(function( {
                            jQuery.yii.submitForm(
                                     this,
                                     'controller/action',{}
                                          );return false;});
                                  });
/*]]>*/
</script>
~~~

## CHtml::textField() method

~~~
public static function textField($name,$value='',$htmlOptions=array())
~~~
Generates a textfield.

***

**Example 1: Generating an empty textfield, just with a name**
~~~
[php]
<?php echo CHtml::textField('Text'); ?>
~~~

***

**Example 2: Generating a textfield with name and value**
~~~
[php]
<?php echo CHtml::textField('Text', 'some value'); ?>
~~~

***

**Example 3: Generating a textfield with customized id, width and maxlength**
~~~
[php]
<?php echo CHtml::textField('Text', 'some value',
 array('id'=>'idTextField', 
       'width'=>100, 
       'maxlength'=>100); ?>
~~~

*Note: use 'cols' instead of 'width' when working with textareas

***

**Example 4: Generating a disabled textfield**
~~~
[php]
<?php echo CHtml::textField('Text', 'some value', 
    array('disabled'=>'disabled'); ?>
~~~

## CHtml::listData() method

~~~
public static function listData($models,$valueField,$textField,$groupField='')
~~~
Generates data for dropDownList and listBox, using the format $key=>$value.


***

**Example 1: Generating a list data for categories**
~~~
[php]
<?php 
     /*you can use here any find method you think 
     proper to return your data from db*/
     $models = categories::model()->findAll();

     // format models resulting using listData     
     $list = CHtml::listData($models, 
                'category_id', 'category_name');    

     print_r($list);
~~~

**HTML Output (Example):**
~~~
[php]
array("1" => "Arts", "2" =>
"Science", "3" => "Culture");
~~~
     

***

**Example 2: Generating an ordered list data for categories using findAll
parameter**
~~~
[php]
<?php 
     $models = categories::model()->findAll(
                 array('order' => 'category_name'));

     $list = CHtml::listData($models, 
                'category_id', 'category_name');    

     print_r($list);
~~~

**HTML Output (Example):**
~~~
[php]
array("1" => "Arts", "3" =>
"Culture", "2" => "Science");
~~~

## CHtml::dropDownList() method

~~~
public static function dropDownList($name,$select,$data,$htmlOptions=array())
~~~
Generates a dropdown list.

$name: A name for the dropdownList;
$select: selected item from the $data
$data: an array of the type $key => $value (the possible values of you
dropdownlist);
$htmlOptions: another options.

***

**Example 1: Generating a simple dropdownlist for gender**
~~~
[php]
<?php echo CHtml::dropDownList('listname', $select, 
              array('M' => 'Male', 'F' => 'Female'));
         
~~~

The $select parameter must contain value 'M' or 'F'.


***

**Example 2: Generating a simple dropdownlist for gender with an 'empty'
element.**

This example will avoid the dropdownlist to be blank when no value, outputing
some proper information to the user
~~~
[php]
<?php echo CHtml::dropDownList('listname', $select, 
              array('M' => 'Male', 'F' => 'Female'),
              array('empty' => '(Select a gender)'));
         
~~~


***

**Example 3: Using data from a model function.**

It is better to have you gender list definition inside your model definition.


At model:
~~~
[php]
public function getGenderOptions(){
    return array('M' => 'Male', 'F' => 'Female');
}
~~~

At view:
~~~
[php]
<?php echo CHtml::dropDownList('listname', $select, 
              $model->genderOptions,
              array('empty' => '(Select a gender'));         
~~~


***

**Example 4: Using data from db**

In order to create a dropdownList with data from db, you have to combine it with
listData method that will format models from db into array of $key=>$value.

This part is equal to listData Example 2:

~~~
[php]
// retrieve the models from db
$models = categories::model()->findAll(
                 array('order' => 'category_name'));

// format models as $key=>$value with listData
$list = CHtml::listData($models, 
                'category_id', 'category_name');
~~~

Now, we generate our dropdowList from the $list variable

~~~
[php]
<?php echo CHtml::dropDownList('categories', $category, 
              $list,
              array('empty' => '(Select a category'));
~~~

**Example 5: Generating dropdownlist with option groups.**

If you need to generate dropdownlist using both `optgroup` and `option` tags use
the following code.

~~~
[php]
<div class="cars-select">
	<?php echo CHtml::dropDownList('Cars', 'car_id', array(
		'Mazda'=>array(
			'mazda-rx7'=>'RX7',
			'mazda-rx5'=>'RX5',
		),
		'Volvo'=>array(
			'volvo-b9tl'=>'B9TL',
			'volvo-l90e-radlader'=>'L90E Radlader',
		),
	)); ?>
</div>
~~~

Code above should generate following HTML.

~~~
[php]
<div class="cars-select">
	<select name="Cars" id="Cars">
		<optgroup label="Mazda">
			<option value="mazda-rx7">RX7</option>
			<option value="mazda-rx5">RX5</option>
		</optgroup>
		<optgroup label="Volvo">
			<option value="volvo-b9tl">B9TL</option>
			<option value="volvo-l90e-radlader">L90E
Radlader</option>
		</optgroup>
	</select>
</div>
~~~

***
You can find CHtml class at `yii/framework/web/helpers/CHtml.php`.

## Links

### Russian
- [Russian Version
dropDownList()](http://dbhelp.ru/by-example-chtml-dropdownlist/page/)  
- [Russian Version listData()](http://dbhelp.ru/by-example-chtml-listdata/page/)
 
- [Russian Version
textField()](http://dbhelp.ru/by-example-chtml-textfield/page/)  
- [Russian Version link()](http://dbhelp.ru/by-example-chtml/page/)

### Japanese
-
[CHtmlの使い方](http://yiijan.org/tutorials/view/chtml%E3%81%AE%E4%BD%BF%E3%81%84%E6%96%B9)