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Der AjaxHelper benutzt die populären Bibliotheken Prototype und script.aculo.us für Ajax und clientseitige Effekte. Um diesen Helfer benutzen zu können musst eine aktuelle Version von www.prototypejs.org und https://script.aculo.us in das /app/webroot/js/-Verzeichnis packen. Außerdem müssen die Bibliotheken in allen Layouts oder Views die AjaxHelper-Funktionalität benötigen, eingebunden werden.
Zuerst müssen die Ajax- und JavaScriptHelper im Controller eingebunden werden:
class WidgetsController extends AppController {
var $name = 'Widgets';
var $helpers = array('Html','Ajax','Javascript');
}
Ist das geschehen, kann die link()
-Methode von JavaScriptHelper
verwendet werden um die Bibliotheken einzubinden:
echo $javascript->link('prototype');
echo $javascript->link('scriptaculous');
Jetzt kann der AjaxHelper verwendet werden:
$ajax->whatever();
Wenn der Controller die RequestHandler Komponente eingebunden hat, benutzt CakePHP automatisch das Ajax-Layout wenn eine Action per Ajax angefragt wird.
class WidgetsController extends AppController {
var $name = 'Widgets';
var $helpers = array('Html','Ajax','Javascript');
var $components = array( 'RequestHandler' );
}
Most of the methods of the AjaxHelper allow you to supply an $options array. You can use this array to configure how the AjaxHelper behaves. Before we cover the specific methods in the helper, let’s look at the different options available through this special array. You’ll want to refer to this section as you start using the methods in the AjaxHelper later on.
$option
keys
Description
$options['evalScripts']
Determines if script tags in the returned content are evaluated. Set to true by default.
$options['frequency']
The number of seconds between interval based checks.
$options['indicator']
The DOM id of an element to show while a request is loading and to hide when a request is completed.
$options['position']
To insert rather than replace, use this option to specify an insertion position of top, bottom, after, or before.
$options['update']
The id of the DOM element to be updated with returned content.
$options['url']
The url of the controller/action that you want to call.
$options['type']
Indicate whether the request should be ‚synchronous‘ or ‚asynchronous‘ (default).
$options['with']
A URL-encoded string which will be added to the URL for get methods or
in to the post body for any other method. Example: x=1&foo=bar&y=2
.
The parameters will be available in $this->params['form']
or
available in $this->data
depending on formatting. For more
information see the Prototype
Serialize method.
Callback options allow you to call JavaScript functions at specific points in the request process. If you’re looking for a way to inject a bit of logic before, after, or during your AjaxHelper operations, use these callbacks to set things up.
$options keys
Description
$options[‚condition‘]
JavaScript code snippet that needs to evaluate to true before request is initiated.
$options[‚before‘]
Executed before request is made. A common use for this callback is to enable the visibility of a progress indicator.
$options[‚confirm‘]
Text to display in a JavaScript confirmation alert before proceeding.
$options[‚loading‘]
Callback code to be executed while data is being fetched from server.
$options[‚after‘]
JavaScript called immediately after request has run; fires before the $options[‚loading‘] callback runs.
$options[‚loaded‘]
Callback code to be executed when the remote document has been received by client.
$options[‚interactive‘]
Called when the user can interact with the remote document, even though it has not finished loading.
$options[‚complete‘]
JavaScript callback to be run when XMLHttpRequest is complete.
link(string $title, mixed $href, array $options, string $confirm, boolean $escapeTitle)
Returns a link to a remote action defined by $options['url']
or
$href
that’s called in the background using XMLHttpRequest when the
link is clicked. The result of that request can then be inserted into a
DOM object whose id can be specified with $options['update']
.
If $options['url']
is blank the href is used instead
Example:
<div id="post">
</div>
<?php echo $ajax->link(
'View Post',
array( 'controller' => 'posts', 'action' => 'view', 1 ),
array( 'update' => 'post' )
);
?>
By default, these remote requests are processed asynchronously during which various callbacks can be triggered
Example:
<div id="post">
</div>
<?php echo $ajax->link(
'View Post',
array( 'controller' => 'posts', 'action' => 'post', 1 ),
array( 'update' => 'post', 'complete' => 'alert( "Hello World" )' )
);
?>
To use synchronous processing specify
$options['type'] = 'synchronous'
.
To automatically set the ajax layout include the RequestHandler component in your controller
By default the contents of the target element are replaced. To change
this behaviour set the $options['position']
Example:
<div id="post">
</div>
<?php echo $ajax->link(
'View Post',
array( 'controller' => 'posts', 'action' => 'view', 1),
array( 'update' => 'post', 'position' => 'top' )
);
?>
$confirm
can be used to call up a JavaScript confirm() message
before the request is run. Allowing the user to prevent execution.
Example:
<div id="post">
</div>
<?php echo $ajax->link(
'Delete Post',
array( 'controller' => 'posts', 'action' => 'delete', 1 ),
array( 'update' => 'post' ),
'Do you want to delete this post?'
);
?>
remoteFunction(array $options);
This function creates the JavaScript needed to make a remote call. It is primarily used as a helper for link(). This is not used very often unless you need to generate some custom scripting.
The $options
for this function are the same as for the link
method
Example:
<div id="post">
</div>
<script type="text/javascript">
<?php echo $ajax->remoteFunction(
array(
'url' => array( 'controller' => 'posts', 'action' => 'view', 1 ),
'update' => 'post'
)
); ?>
</script>
It can also be assigned to HTML Event Attributes:
<?php
$remoteFunction = $ajax->remoteFunction(
array(
'url' => array( 'controller' => 'posts', 'action' => 'view', 1 ),
'update' => 'post' )
);
?>
<div id="post" onmouseover="<?php echo $remoteFunction; ?>" >
Mouse Over This
</div>
If $options['update']
is not passed, the browser will ignore the
server response.
remoteTimer(array $options)
Periodically calls the action at $options['url']
, every
$options['frequency']
seconds. Usually used to update a specific div
(specified by $options['update']
) with the result of the remote
call. Callbacks can be used.
remoteTimer
is the same as the remoteFunction
except for the
extra $options['frequency']
Example:
<div id="post">
</div>
<?php
echo $ajax->remoteTimer(
array(
'url' => array( 'controller' => 'posts', 'action' => 'view', 1 ),
'update' => 'post', 'complete' => 'alert( "request completed" )',
'position' => 'bottom', 'frequency' => 5
)
);
?>
The default $options['frequency']
is 10 seconds
form(string $action, string $type, array $options)
Returns a form tag that submits to $action using XMLHttpRequest instead of a normal HTTP request via $type (‚post‘ or ‚get‘). Otherwise, form submission will behave exactly like normal: data submitted is available at $this->data inside your controllers. If $options[‚update‘] is specified, it will be updated with the resulting document. Callbacks can be used.
The options array should include the model name e.g.
$ajax->form('edit','post',array('model'=>'User','update'=>'UserInfoDiv'));
Alternatively, if you need to cross post to another controller from your form:
$ajax->form(array('type' => 'post',
'options' => array(
'model'=>'User',
'update'=>'UserInfoDiv',
'url' => array(
'controller' => 'comments',
'action' => 'edit'
)
)
));
You should not use the $ajax->form()
and $ajax->submit()
in the
same form. If you want the form validation to work properly use the
$ajax->submit()
method as shown below.
submit(string $title, array $options)
Returns a submit button that submits the form to $options['url']
and
updates the div specified in $options['update']
<div id='testdiv'>
<?php
echo $form->create('User');
echo $form->input('email');
echo $form->input('name');
echo $ajax->submit('Submit', array('url'=> array('controller'=>'users', 'action'=>'add'), 'update' => 'testdiv'));
echo $form->end();
?>
</div>
Use the $ajax->submit()
method if you want form validation to work
properly. i.e. You want the messages you specify in your validation
rules to show up correctly.
observeField(string $field, array $options)
Observes the field with the DOM id specified by $field (every $options[‚frequency‘] seconds) and makes an XMLHttpRequest when its contents have changed.
When no frequency or a small frequency interval (between 0 and 1) is
specified, a prototype Form.Element.EventObserver
will be used
instead of a Form.Element.Observer
. The
Form.Element.EventObserver
is not timed and will execute at the same
time the value of the element has changed.
<?php echo $form->create( 'Post' ); ?>
<?php $titles = array( 1 => 'Tom', 2 => 'Dick', 3 => 'Harry' ); ?>
<?php echo $form->input( 'title', array( 'options' => $titles ) ) ?>
</form>
<?php
echo $ajax->observeField( 'PostTitle',
array(
'url' => array( 'action' => 'edit' ),
'frequency' => 0.2,
)
);
?>
observeField
uses the same options as link
The field to send up can be set using $options['with']
. This
defaults to Form.Element.serialize('$field')
. Data submitted is
available at $this->data
inside your controllers. Callbacks can be
used with this function.
To send up the entire form when the field changes use
$options['with'] = Form.serialize( $('Form ID') )
observeForm(string $form, array $options)
Similar to observeField(), but operates on an entire form identified by the DOM id $form. The supplied $options are the same as observeField(), except the default value of the $options[‚with‘] option evaluates to the serialized (request string) value of the form.
autoComplete(string $field, string $url, array $options)
Renders a text field with $field with autocomplete. The remote action at $url should return a suitable list of autocomplete terms. Often an unordered list is used for this. First, you need to set up a controller action that fetches and organizes the data you’ll need for your list, based on user input:
function autoComplete() {
//Partial strings will come from the autocomplete field as
//$this->data['Post']['subject']
$this->set('posts', $this->Post->find('all', array(
'conditions' => array(
'Post.subject LIKE' => $this->data['Post']['subject'].'%'
),
'fields' => array('subject')
)));
$this->layout = 'ajax';
}
Next, create app/views/posts/auto_complete.ctp
that uses that data
and creates an unordered list in (X)HTML:
<ul>
<?php foreach($posts as $post): ?>
<li><?php echo $post['Post']['subject']; ?></li>
<?php endforeach; ?>
</ul>
Finally, utilize autoComplete() in a view to create your auto-completing form field:
<?php echo $form->create('User', array('url' => '/users/index')); ?>
<?php echo $ajax->autoComplete('Post.subject', '/posts/autoComplete')?>
<?php echo $form->end('View Post')?>
Once you’ve got the autoComplete() call working correctly, use CSS to style the auto-complete suggestion box. You might end up using something similar to the following:
div.auto_complete {
position :absolute;
width :250px;
background-color :white;
border :1px solid #888;
margin :0px;
padding :0px;
}
li.selected { background-color: #ffb; }
If you want the user to enter a minimum number of characters before the autocomplete starts, you can use the minChars-Option as follows:
$ajax->autoComplete('Post.subject', '/posts/autoComplete',array('minChars' => 3));
isAjax()
Allows you to check if the current request is a Prototype Ajax request inside a view. Returns a boolean. Can be used for presentational logic to show/hide blocks of content.
drag(string $id, array $options)
Makes a Draggable element out of the DOM element specified by $id. For more information on the parameters accepted in $options see https://github.com/madrobby/scriptaculous/wikis/draggable.
Common options might include:
$options keys |
Description |
---|---|
$options[‚handle‘] |
Sets whether the element should only be draggable by an embedded handle. The value must be an element reference or element id or a string referencing a CSS class value. The first child/grandchild/etc. element found within the element that has this CSS class value will be used as the handle. |
$options[‚revert‘] |
If set to true, the element returns to its original position when the drags ends. Revert can also be an arbitrary function reference, called when the drag ends. |
$options[‚constraint‘] |
Constrains the drag to either ‚horizontal‘ or ‚vertical‘, leave blank for no constraints. |
drop(string $id, array $options)
Makes the DOM element specified by $id able to accept dropped elements. Additional parameters can be specified with $options. For more information see https://github.com/madrobby/scriptaculous/wikis/droppables.
Common options might include:
$options keys |
Description |
---|---|
$options[‚accept‘] |
Set to a string or javascript array of strings describing CSS classes that the droppable element will accept. The drop element will only accept elements of the specified CSS classes. |
$options[‚containment‘] |
The droppable element will only accept the dragged element if it is contained in the given elements (element ids). Can be a string or a javascript array of id references. |
$options[‚overlap‘] |
If set to ‚horizontal‘ or ‚vertical‘, the droppable element will only react to a draggable element if it is overlapping the droparea by more than 50% in the given axis. |
$options[‚onDrop‘] |
A javascript call back that is called when the dragged element is dropped on the droppable element. |
dropRemote(string $id, array $options)
Makes a drop target that creates an XMLHttpRequest when a draggable element is dropped on it. The $options array for this function are the same as those specified for drop() and link().
slider(string $id, string $track_id, array $options)
Creates a directional slider control. For more information see https://wiki.github.com/madrobby/scriptaculous/slider.
Common options might include:
$options keys
Description
$options[‚axis‘]
Sets the direction the slider will move in. ‚horizontal‘ or ‚vertical‘. Defaults to horizontal
$options[‚handleImage‘]
The id of the image that represents the handle. This is used to swap out the image src with disabled image src when the slider is enabled. Used in conjunction with handleDisabled.
$options[‚increment‘]
Sets the relationship of pixels to values. Setting to 1 will make each pixel adjust the slider value by one.
$options[‚handleDisabled‘]
The id of the image that represents the disabled handle. This is used to change the image src when the slider is disabled. Used in conjunction handleImage.
$options[‚onChange‘]
JavaScript callback fired when the slider has finished moving, or has its value changed. The callback function receives the slider’s current value as a parameter.
$options[‚onSlide‘]
JavaScript callback that is called whenever the slider is moved by dragging. It receives the slider’s current value as a parameter.
editor(string $id, string $url, array $options)
Creates an in-place editor at DOM id. The supplied $url
should be an
action that is responsible for saving element data. For more information
and demos see
https://github.com/madrobby/scriptaculous/wikis/ajax-inplaceeditor.
Common options might include:
$options keys
Description
$options['collection']
Activate the ‚collection‘ mode of in-place editing. $options[‚collection‘] takes an array which is turned into options for the select. To learn more about collection see https://github.com/madrobby/scriptaculous/wikis/ajax-inplacecollectioneditor.
$options['callback']
A function to execute before the request is sent to the server. This can
be used to format the information sent to the server. The signature is
function(form, value)
$options['okText']
Text of the submit button in edit mode
$options['cancelText']
The text of the link that cancels editing
$options['savingText']
The text shown while the text is sent to the server
$options['formId']
$options['externalControl']
$options['rows']
The row height of the input field
$options['cols']
The number of columns the text area should span
$options['size']
Synonym for ‘cols’ when using single-line
$options['highlightcolor']
The highlight color
$options['highlightendcolor']
The color which the highlight fades to
$options['savingClassName']
$options['formClassName']
$options['loadingText']
$options['loadTextURL']
Example
<div id="in_place_editor_id">Text To Edit</div>
<?php
echo $ajax->editor(
"in_place_editor_id",
array(
'controller' => 'Posts',
'action' => 'update_title',
$id
),
array()
);
?>
sortable(string $id, array $options)
Makes a list or group of floated objects contained by $id sortable. The options array supports a number of parameters. To find out more about sortable see https://wiki.github.com/madrobby/scriptaculous/sortable.
<div id='sortableContainer'>
<div id='element_1' class='sortableItem'>
Element 1
</div>
<div id='element_2' class='sortableItem'>
Element 2
</div>
<div id='element_3' class='sortableItem'>
Element 3
</div>
</div>
<script type='text/javascript'>
function writeupdate () {
var id_array = Sortable.sequence('sortableContainer');
new Ajax.Request('/reports/updatesortorder/'+ id_array.join(','),
{
onSuccess: function() {alert("Order Updated");}
}
);
}
</script>
<?php
echo $ajax->sortable('sortableContainer',array('tag'=>'div','only'=>'sortableItem','onUpdate'=>'writeupdate'));
?>
Make sure that you do not include the parenthesis on the onUpdate callback, or it will not execute.
Common options might include:
$options keys
Description
$options[‚tag‘]
Indicates what kind of child elements of the container will be made sortable. Defaults to ‚li‘.
$options[‚only‘]
Allows for further filtering of child elements. Accepts a CSS class.
$options[‚overlap‘]
Either ‚vertical‘ or ‚horizontal‘. Defaults to vertical.
$options[‚constraint‘]
Restrict the movement of the draggable elements. accepts ‚horizontal‘ or ‚vertical‘. Defaults to vertical.
$options[‚handle‘]
Makes the created Draggables use handles, see the handle option on Draggables.
$options[‚onUpdate‘]
Called when the drag ends and the Sortable’s order is changed in any way. When dragging from one Sortable to another, the callback is called once on each Sortable.
$options[‚hoverclass‘]
Give the created droppable a hoverclass.
$options[‚ghosting‘]
If set to true, dragged elements of the sortable will be cloned and appear as a ghost, instead of directly manipulating the original element.