A TreeLoader provides for lazy loading of an
Ext.tree.TreeNode's child
nodes from a specified URL. The response must be a JavaScript Array definition
whose elements are node definition objects. e.g.:
[{
id: 1,
text: 'A leaf Node',
leaf: true
},{
id: 2,
text: 'A folder Node',
children: [{
id: 3,
text: 'A child Node',
leaf: true
}]
}]
A server request is sent, and child nodes are loaded only when a node is expanded.
The loading node's id is passed to the server under the parameter name "node" to
enable the server to produce the correct child nodes.
To pass extra parameters, an event handler may be attached to the "beforeload"
event, and the parameters specified in the TreeLoader's baseParams property:
myTreeLoader.on("beforeload", function(treeLoader, node) {
this.baseParams.category = node.attributes.category;
}, this);
This would pass an HTTP parameter called "category" to the server containing
the value of the Node's "category" attribute.
Defined By
Config Options
An object containing attributes to be added to all nodes
created by this loader. If the attributes sent by the server...
An object containing attributes to be added to all nodes
created by this loader. If the attributes sent by the server have an attribute in this object,
they take priority.
An object containing properties which
specify HTTP parameters to be passed to each request for child nodes.
An object containing properties which
specify HTTP parameters to be passed to each request for child nodes.
Default to true. Remove previously existing
child nodes before loading.
Default to true. Remove previously existing
child nodes before loading.
The URL from which to request a Json string which
specifies an array of node definition objects representing the chil...
The URL from which to request a Json string which
specifies an array of node definition objects representing the child nodes
to be loaded.
Function to call when executing a request.
Function to call when executing a request.
A config object containing one or more event handlers to be added to this
object during initialization. This should ...
A config object containing one or more event handlers to be added to this
object during initialization. This should be a valid listeners config object as specified in the
addListener example for attaching multiple handlers at once.
DOM events from ExtJs Components
While some ExtJs Component classes export selected DOM events (e.g. "click", "mouseover" etc), this
is usually only done when extra value can be added. For example the DataView's
click event passing the node clicked on. To access DOM
events directly from a child element of a Component, we need to specify the element option to
identify the Component property to add a DOM listener to:
new Ext.panel.Panel({
width: 400,
height: 200,
dockedItems: [{
xtype: 'toolbar'
}],
listeners: {
click: {
element: 'el', //bind to the underlying el property on the panel
fn: function(){ console.log('click el'); }
},
dblclick: {
element: 'body', //bind to the underlying body property on the panel
fn: function(){ console.log('dblclick body'); }
}
}
});
The name of the parameter sent to the server which contains
the identifier of the node. Defaults to 'node'.
The name of the parameter sent to the server which contains
the identifier of the node. Defaults to 'node'.
Defaults to undefined. Only used when using directFn.
Specifies the params in the order in which they must be passed ...
Defaults to
undefined. Only used when using directFn.
Specifies the params in the order in which they must be passed to the server-side Direct method
as either (1) an Array of String values, or (2) a String of params delimited by either whitespace,
comma, or pipe. For example,
any of the following would be acceptable:
nodeParameter: 'node',
paramOrder: ['param1','param2','param3']
paramOrder: 'node param1 param2 param3'
paramOrder: 'param1,node,param2,param3'
paramOrder: 'param1|param2|param|node'
Only used when using directFn.
Send parameters as a collection of named arguments (defaults to false). Providing a
pa...
Only used when using directFn.
Send parameters as a collection of named arguments (defaults to
false). Providing a
paramOrder nullifies this configuration.
If set to true, the loader recursively loads "children" attributes when doing the first load on nodes.
If set to true, the loader recursively loads "children" attributes when doing the first load on nodes.
The HTTP request method for loading data (defaults to the value of
Ext.Ajax-method).
The HTTP request method for loading data (defaults to the value of
Ext.Ajax-method).
An object containing properties which
specify custom Ext.tree.TreeNodeUI implementations. If the optional
uiProvider ...
An object containing properties which
specify custom
Ext.tree.TreeNodeUI implementations. If the optional
uiProvider attribute of a returned child node is a string rather
than a reference to a TreeNodeUI implementation, then that string value
is used as a property name in the uiProviders object.
Defined By
Methods
Creates a new Treeloader.
Creates a new Treeloader.
Parameters
Returns
addEvents(
Object|String o, string Optional.)
: Void
Adds the specified events to the list of events which this Observable may fire.
Adds the specified events to the list of events which this Observable may fire.
Parameters
Returns
addListener(
String eventName, Function handler, [Object scope], [Object options])
: Void
Appends an event handler to this object.
Appends an event handler to this object.
Parameters
- eventName : String
The name of the event to listen for. May also be an object who's property names are event names. See
- handler : Function
The method the event invokes.
- scope : Object
(optional) The scope (this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
- options : Object
(optional) An object containing handler configuration.
properties. This may contain any of the following properties:
- scope : Object
The scope (this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
- delay : Number
The number of milliseconds to delay the invocation of the handler after the event fires.
- single : Boolean
True to add a handler to handle just the next firing of the event, and then remove itself.
- buffer : Number
Causes the handler to be scheduled to run in an
Ext.util.DelayedTask delayed
by the specified number of milliseconds. If the event fires again within that time, the original
handler is
not invoked, but the new handler is scheduled in its place.
- target : Observable
Only call the handler if the event was fired on the target Observable, not
if the event was bubbled up from a child Observable.
- element : String
This option is only valid for listeners bound to Components.
The name of a Component property which references an element to add a listener to.
This option is useful during Component construction to add DOM event listeners to elements of Components which
will exist only after the Component is rendered. For example, to add a click listener to a Panel's body:
new Ext.panel.Panel({
title: 'The title',
listeners: {
click: this.handlePanelClick,
element: 'body'
}
});
When added in this way, the options available are the options applicable to Ext.core.Element-addListener
Combining Options
Using the options argument, it is possible to combine different types of listeners:
A delayed, one-time listener.
myPanel.on('hide', this.handleClick, this, {
single: true,
delay: 100
});
Attaching multiple handlers in 1 call
The method also allows for a single argument to be passed which is a config object containing properties
which specify multiple events. For example:
myGridPanel.on({
cellClick: this.onCellClick,
mouseover: this.onMouseOver,
mouseout: this.onMouseOut,
scope: this // Important. Ensure "this" is correct during handler execution
});
.
Returns
addManagedListener(
Observable|Element item, Object|String ename, Function fn, Object scope, Object opt)
: Void
Adds listeners to any Observable object (or Element) which are automatically removed when this Component
is destroyed...
Adds listeners to any Observable object (or Element) which are automatically removed when this Component
is destroyed.
Parameters
- item : Observable|Element
The item to which to add a listener/listeners.
- ename : Object|String
The event name, or an object containing event name properties.
- fn : Function
Optional. If the ename parameter was an event name, this
is the handler function.
- scope : Object
Optional. If the ename parameter was an event name, this
is the scope (this reference) in which the handler function is executed.
- opt : Object
Optional. If the
ename parameter was an event name, this
is the
addListener options.
Returns
Removes all listeners for this object including the managed listeners
Removes all listeners for this object including the managed listeners
Returns
Removes all managed listeners for this object.
Removes all managed listeners for this object.
Returns
Override this function for custom TreeNode node implementation, or to
modify the attributes at creation time.
Example...
Override this function for custom TreeNode node implementation, or to
modify the attributes at creation time.
Example:
new Ext.tree.TreePanel({
...
loader: new Ext.tree.TreeLoader({
url: 'dataUrl',
createNode: function(attr) {
// Allow consolidation consignments to have
// consignments dropped into them.
if (attr.isConsolidation) {
attr.iconCls = 'x-consol',
attr.allowDrop = true;
}
return Ext.tree.TreeLoader.prototype.createNode.call(this, attr);
}
}),
...
});
Parameters
Returns
Enables events fired by this Observable to bubble up an owner hierarchy by calling
this.getBubbleTarget() if present....
Enables events fired by this Observable to bubble up an owner hierarchy by calling
this.getBubbleTarget() if present. There is no implementation in the Observable base class.
This is commonly used by Ext.Components to bubble events to owner Containers. See Ext.Component-getBubbleTarget. The default
implementation in Ext.Component returns the Component's immediate owner. But if a known target is required, this can be overridden to
access the required target more quickly.
Example:
Ext.override(Ext.form.Field, {
// Add functionality to Field's initComponent to enable the change event to bubble
initComponent : Ext.Function.createSequence(Ext.form.Field.prototype.initComponent, function() {
this.enableBubble('change');
}),
// We know that we want Field's events to bubble directly to the FormPanel.
getBubbleTarget : function() {
if (!this.formPanel) {
this.formPanel = this.findParentByType('form');
}
return this.formPanel;
}
});
var myForm = new Ext.formPanel({
title: 'User Details',
items: [{
...
}],
listeners: {
change: function() {
// Title goes red if form has been modified.
myForm.header.setStyle('color', 'red');
}
}
});
Parameters
Returns
fireEvent(
String eventName, Object... args)
: Boolean
Fires the specified event with the passed parameters (minus the event name).
An event may be set to bubble up an Obse...
Fires the specified event with the passed parameters (minus the event name).
An event may be set to bubble up an Observable parent hierarchy (See Ext.Component-getBubbleTarget)
by calling enableBubble.
Parameters
Returns
- Boolean returns false if any of the handlers return false otherwise it returns true.
Checks to see if this object has any listeners for a specified event
Checks to see if this object has any listeners for a specified event
Parameters
Returns
- Boolean True if the event is being listened for, else false
load(
Ext.tree.TreeNode node, Function callback, Object scope)
: Void
Load an Ext.tree.TreeNode from the URL specified in the constructor.
This is called automatically when a node is expa...
Load an
Ext.tree.TreeNode from the URL specified in the constructor.
This is called automatically when a node is expanded, but may be used to reload
a node (or append new children if the
clearOnLoad option is false.)
Parameters
- node : Ext.tree.TreeNode
- callback : Function
Function to call after the node has been loaded. The
function is passed the TreeNode which was requested to be loaded.
- scope : Object
The scope (this reference) in which the callback is executed.
defaults to the loaded TreeNode.
Returns
on(
String eventName, Function handler, [Object scope], [Object options])
: Void
Appends an event handler to this object (shorthand for addListener.)
Appends an event handler to this object (shorthand for
addListener.)
Parameters
- eventName : String
The type of event to listen for
- handler : Function
The method the event invokes
- scope : Object
(optional) The scope (this reference) in which the handler function is executed.
If omitted, defaults to the object which fired the event.
- options : Object
(optional) An object containing handler configuration.
Returns
Relays selected events from the specified Observable as if the events were fired by this.
Relays selected events from the specified Observable as if the events were fired by
this.
Parameters
Returns
removeListener(
String eventName, Function handler, [Object scope])
: Void
Removes an event handler.
Removes an event handler.
Parameters
Returns
Removes listeners that were added by the mon method.
Removes listeners that were added by the
mon method.
Parameters
- item : Observable|Element
The item from which to remove a listener/listeners.
- ename : Object|String
The event name, or an object containing event name properties.
- fn : Function
Optional. If the ename parameter was an event name, this
is the handler function.
- scope : Object
Optional. If the ename parameter was an event name, this
is the scope (this reference) in which the handler function is executed.
Returns
Resume firing events. (see suspendEvents)
If events were suspended using the queueSuspended parameter, then all
event...
Resume firing events. (see
suspendEvents)
If events were suspended using the
queueSuspended parameter, then all
events fired during event suspension will be sent to any listeners now.
Returns
Suspend the firing of all events. (see resumeEvents)
Suspend the firing of all events. (see
resumeEvents)
Parameters
- queueSuspended : Boolean
Pass as true to queue up suspended events to be fired
after the
resumeEvents call instead of discarding all suspended events;
Returns
un(
String eventName, Function handler, [Object scope])
: Void
Removes an event handler (shorthand for removeListener.)
Removes an event handler (shorthand for
removeListener.)
Parameters
Returns
Defined By
Events
beforeload(
Object This, Object node, Object callback)
Fires before a network request is made to retrieve the Json text which specifies a node's children.
Fires before a network request is made to retrieve the Json text which specifies a node's children.
Parameters
- This : Object
TreeLoader object.
- node : Object
- callback : Object
The callback function specified in the
load call.
load(
Object This, Object node, Object response)
Fires when the node has been successfuly loaded.
Fires when the node has been successfuly loaded.
Parameters
Fires if the network request failed.
Fires if the network request failed.
Parameters