# UI fragments
Fragments are a set of UI snippets, which can be used to insert,delete, or modify the components in UI template. It is suitable to facilitate a small amount of UI customization based on built-in templates.
If you need a lot of custom layout and device adaptation, please refer to the methods described in Appearance and layout template.
# simple example
The following code will use fragments configuration to remove the comment-tab
component from the mobile and desktop/tablet layouts. Click "run" to run the example, and you can use the device mode of Chrome DevTool to simulate the running effect of mobile/tablet.
# The description of the Fragment configuration parameters
target
: The name of the control, and each name is unique.action
: Indicates the action mode of the fragment snippets. The default action mode isUIExtension.UIConsts.FRAGMENT_ACTION.EXT
. The specifics are as follows:UIExtension.UIConsts.FRAGMENT_ACTION.EXT
: Extend the target control.UIExtension.UIConsts.FRAGMENT_ACTION.BEFORE
: Insert a new control before the target control.UIExtension.UIConsts.FRAGMENT_ACTION.AFTER
: Insert a new control after the target control.UIExtension.UIConsts.FRAGMENT_ACTION.APPEND
: Insert a new control into the target control (the target control must be a container).UIExtension.UIConsts.FRAGMENT_ACTION.FILL
: Empty the child space of the target control and fill with a new control. Make sure that the target control must be a container.UIExtension.UIConsts.FRAGMENT_ACTION.REPLACE
: Replace the target control with a new control.UIExtension.UIConsts.FRAGMENT_ACTION.REMOVE
: Delete the target control.
template
: The template of the control. The content is in XML format and action is BEFORE/AFTER/APPEND/FILL/REPLACE.config
: Control configuration object. It is invalid when action is REMOVE.config.target
: The name of the control in the above template. It is only required when action is BEFORE/AFTER/APPEND/FILL/REPLACE.config.attrs
: Set the html property of the control.config.callback
: The business logic implementation of the control. There are three ways to implement it:function: The events of control will call this function, and override the built-in callbacks. The basic components that support function are (xbutton, dropdown-button, context-menu-item). If you want to add functionalities based on the built-in callbacks, you can use the second method.
controller class: Controller class can listen for components lifecycle and handle more component events:
{ target: 'hand-tool', config: { callback: class extends UIExtension.Controller { mounted() { super.mounted(); this.component.element.addEventListener('hover', e => { console.info('mouse over', this.component) }) } handle() { console.info('hand-tool clicked') } } } }
decorator object: it contains a series of function hooks for blocking the execution of the controller handle method, including before, after, thrown, and around.
{ target: 'hand-tool', config: { callback: { before: function() { // The function executed before calling the handle method of controller. It can receive all parameters of the handle method. }, after: function(returnValue) { // The function executed after calling the handle method of controller. It can receive the return value and parameters of the handle function. }, thrown: function(error) { // The function executed when the handle method of controller throws an exception. It can receive the exception object and parameters. }, around: function(callback, args) { // It can receive the references and parameters of controller's handle method. Inside the around callback, you can execute code before/after running the handle function, or in the catch exception block. It also can decide whether to execute the handle method. try{ console.info('before callback'); var ret; if(callback instanceof UIExtension.Controller) { ret = callback.handle(...args); } else { ret = callback.apply(this, args); } console.info('after callback'); return ret; }catch(e) { console.error(e, 'an error occurred'); } finally { console.info(''); } } } } }
# Note
It is recommended that only use fragment for UI fine-tuning. If you want to substantially modify the built-in layout, please refer to the methods described in Appearance and layout template.