Events that fire on a page with a Webix-based application fall into three groups:
Common inner events for all UI components are mouse events (onItemClick, onBeforeContextMenu, onMouseMoving, onMouseOut, etc.) since all the components can be clicked (and right-clicked) and respond to a mouse pointer.
Other inner events depend on the component functionality and are provided in API references for each component.
A handler can be attached to a component in various ways:
1. The most common one is to do it with the help of:
2. Depending on the component nature, you can attach a handler to some specific events defined by component properties:
Now let's study each way in detail.
The attachEvent() method takes two parameters - the name of the component's inner event and a function (handler) to fire:
$$("element_id").attachEvent("onSomeEvent", function(){/* logic of the handler */});
Event names are case-insensitive.
A button to collapse the all tree nodes
var myEvent = $$("button_id").attachEvent("onItemClick", function(){
$$("dtree").closeAll();
});
Later on, you can easily detach this event from the component with the help of the opposite method:
$$("button_id").detachEvent(myEvent);
You can also define event handlers right in the component constructor within either of the following properties:
webix.ui({
rows:[
{
view:"button",
click:function(){ }
},
{
view:"list",
data:[ ],
ready:function(){ }
},
{
view: "list",
on:{
onItemClick: function(id){
alert("You have clicked on an item with id="+id);
}
}
}
]
});
Related sample: Attaching Functions in the Constructor
The on property allows you to declare a handler outside the webix.ui() constructor and specify its name as a value for the desired event:
function select_first(){
$$("list").select($$("list").getFirstId();)
};
webix.ui({
view:"button",
on:{
"onItemClick": select_first
}
});
Related sample: Creating a Custom Table
For buttons you can make it more compact by using the click property:
function close_tree(){/* ... */};
{view:"button", id:"sample_button", value:"Close", width:100, click:close_tree }
While data components inherit methods from DataStore and TreeStore, events aren't inherited. That's why they should be attached through the data object:
view.data.attachEvent("onParse", function(driver, data){
// some code
});
There are also two alternative ways to attach such events:
datatable.attachEvent("data->onParse", function(driver, data){
// some code
});
view:"datatable",
on:{
"data->onStoreUpdated":function(){
// some code
}
}
Related sample: Datatable: Index Column
Data scheme allows changing the default pattern of data handling within the component.
For instance, the function specified in its $init key will run each time when the data are loaded/reloaded to the component and when the add method is called.
webix.ui({
view:"list",
scheme:{
$init:function(obj){/* ... */},
$update:function(obj){/* ... */}
}
});
Related sample: Horizontal List
More possibilities of the data scheme are described separately.
Such properties come in pairs and include:
All these properties allow attaching the corresponding behavior (clicking, double-clicking, etc.) for the items of a component with a specified CSS class, thus redefining the default behavior.
Let's have a look at the examples on how you can use the onClick and on_click handlers.
1. With on_click, you can redefine clicking only after the component initialization.
The on_click handler:
grid = webix.ui({
view:"datatable",
columns:[
{ id:"", template:"<input type='button' class='delbtn' value='Delete'>"},
{ id:"title", /* ... */}
],
on:{
"onItemClick":function(){/* ... */} // the default click behavior
},
select:true
});
grid.on_click.delbtn = function(e, id, trg){
webix.message("Delete row: "+id);
return false; // blocks the default onclick event
};
Related sample: Datatable: Custom Handler
One of the columns has an HTML template with a button styled with the 'delbtn' CSS class. All cells including the one with this button will react on the default click behavior. When you click on the button itself rather than on its cell area, the default behavior will be overridden with the function attached to the the 'delbtn' CSS class.
2. The onClick handler allows redefining the current click behavior right in the component constructor.
webix.ui({
view:"list",
template:"#votes# <span class='info'>Details</span>",
select:"multiselect",
onClick:{
info:function(e, id){
webix.message(this.item(id).title);
return false; // blocks the default onclick event
}
},
});
When you click on the list item styled with the info CSS class, the item won't be selected and a custom message will appear.
Note that returning false from the onClick handler blocks all further click-related events: onBeforeSelect, onAfterSelect, onSelectChange, onItemClick. To check the full stack of the blocked events, you should enable the debug version of the Webix library.
Related sample: List: Event Handlers
The same pattern is true for other pairs of properties.
Event Mapping helps to avoid repetitions in code when one and the same event should be attached to different components. If you have already attached an event to a component and described the handler function, you can route this event to another component in your app.
For these needs, call the mapEvent method passing map into it, where the map is an event-object correspondence:
webix.ui({
rows:[
{ view:"list", id:"list1", data:list_data, on:{
onItemClick:getItemValue
}},
{ view:"list", id:"list2", data:list_data}
]
});
// here event name should be in the lower case
$$("list2").mapEvent({onitemclick:$$("list1")});
As a result, when the second list is clicked, the function that was initially attached only to the first one, will be executed for the second as well:
function getItemValue(id){
var obj = this.$eventSource || this;
var value = obj.getItem(id).value;
webix.message("List: "+obj.config.id+", clicked: "+id);
}
Note that if you need to access the object for which the handler is called at the moment, you can do it via the $eventSource property. this will always point to the object for which the handler is attached initially.
Inner events make it possible to work with component items provided that the ID of an item you click, select, etc. is passed to the attached function.
For instance, you need an event that fires each time you click on an item in the list and performs an action that manipulates its data.
$$("mylist").attachEvent("onAfterSelect",function(id){
alert(this.item(id).title);
});
Related sample: Sizing and Events
Events can be divided into two groups:
The function returns false, selection is blocked
$$("my_list").attachEvent("onBeforeSelect", function(){ return false; })
You can also temporarily block all events associated with the component by using the blockEvent() method. To re-enable event triggering use the unblockEvent() method.
$$("component_id").blockEvent();
$$("component_id").unblockEvent();
The default value for response to events is 500 ms. With such events as onMouseMove and onMouseOut, you can delay the server response for as much time (in milliseconds) as you need:
webix.ui({
view:"menu",
mouseEventDelay:100
});
Components that are in focus at the moment automatically receive an ability to respond to keyboard actions and can take keyboard events, namely:
Look how the onTimedKeyPress event works with a text field to filter data in view list:
$$("list_input").attachEvent("onTimedKeyPress",function(){
var value = this.getValue().toLowerCase();
$$("list").filter(function(obj){
return obj.title.toLowerCase().indexOf(value)==0;
});
});
// "list_input" id is the ID of the dedicated "text" input control
Related sample: List: Filtering
More information about key codes and hot keys is to be found in the UI Manager article.
Webix global events are not connected with any specific component and can be used to control general application issues (clicks, touch movements, server-side requests, etc). Some of them repeat native DOM events.
All such events are attached to the webix object:
webix.attachEvent("onRotate", function(mode){
// logic
});
The details on Touch Events are given in the related part of API reference.
Note that these events will fire only for Ajax requests issued by Webix. It can be a custom request created with Webix Ajax interface or an automatic one (issued by a data component during data loading or saving).
Native DOM events can be handled with the help of the Webix event() and eventRemove() functions that are called from the webix object:
var eventId = webix.event("divId", "click", function(e){
do_something();
});
webix.eventRemove(eventId);
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