Module Ext_util_ElementContainer

module Ext_util_ElementContainer: sig .. end

This mixin enables classes to declare relationships to child elements and provides the mechanics for acquiring the elements and storing them on an object instance as properties.

This class is used by components and container layouts to manage their child elements.

A typical component that uses these features might look something like this:

 Ext.define('Ext.ux.SomeComponent', {
     extend: 'Ext.Component',

     childEls: [
         'bodyEl'
     ],

     renderTpl: [
         '<div id="{id}-bodyEl"></div>'
     ],

     // ...
 });

The childEls array lists one or more relationships to child elements managed by the component. The items in this array can be either of the following types:

• String: the id suffix and property name in one. For example, "bodyEl" in the above example means a "bodyEl" property will be added to the instance with the result of Ext.get given "componentId-bodyEl" where "componentId" is the component instance's id.
• Object: with a name property that names the instance property for the element, and one of the following additional properties:
  • id: The full id of the child element.
  • itemId: The suffix part of the id to which "componentId-" is prepended.
  • select: A selector that will be passed to Ext.select.
  • selectNode: A selector that will be passed to Ext.DomQuery.selectNode.

The example above could have used this instead to achieve the same result:

 childEls: [
     { name: 'bodyEl', itemId: 'bodyEl' }
 ]

When using select, the property will be an instance of Ext.CompositeElement. In all other cases, the property will be an Ext.Element or null if not found.

Care should be taken when using select or selectNode to find child elements. The following issues should be considered:

• Performance: using selectors can be slower than id lookup by a factor 10x or more.
• Over-selecting: selectors are applied after the DOM elements for all children have been rendered, so selectors can match elements from child components (including nested versions of the same component) accidentally.

This above issues are most important when using select since it returns multiple elements.

IMPORTANT Unlike a renderTpl where there is a single value for an instance, childEls are aggregated up the class hierarchy so that they are effectively inherited. In other words, if a class where to derive from Ext.ux.SomeComponent in the example above, it could also have a childEls property in the same way as Ext.ux.SomeComponent.

 Ext.define('Ext.ux.AnotherComponent', {
     extend: 'Ext.ux.SomeComponent',

     childEls: [
         // 'bodyEl' is inherited
         'innerEl'
     ],

     renderTpl: [
         '<div id="{id}-bodyEl">'
             '<div id="{id}-innerEl"></div>'
         '</div>'
     ],

     // ...
 });

The renderTpl contains both child elements and unites them in the desired markup, but the childEls only contains the new child element. The applyChildEls method takes care of looking up all childEls for an instance and considers childEls properties on all the super classes and mixins.

class type t = object .. end

class type configs = object .. end

class type events = object .. end

class type statics = object .. end

val of_configs : configs Js.t -> t Js.t

val to_configs : t Js.t -> configs Js.t