# JSEnv Extend

# Api

Map<String, Object> options = new HashMap();
instance.render(pagename, template,options);

# usage

var value = weex.config.testValue;


# Module extend

  1. Customize modules class must extend from WXModule.
  2. Extended method must add @JSMethod (uiThread = false or true) annotation, which determines whether the method is run on UI thread.
  3. The access level of method must be public.
  4. Do not obfuscate code using tools like ProGuard.
  5. Extended method suppport the data type of int, double, float, String, Map, List as its param.
  6. Register the module: WXSDKEngine.registerModule("MyModule", MyModule.class);or else may report an error: ReportException :undefined:9: TypeError: Object #<Object> has no method 'xxx' .

Refer to the following example:

public class MyModule extends WXModule{

  //run ui thread
  @JSMethod (uiThread = true)
  public void printLog(String msg) {

  //run JS thread
  @JSMethod (uiThread = false)
  public void fireEventSyncCall(){
   //implement your module logic here

Register the module

WXSDKEngine.registerModule("MyModule", MyModule.class);

Use this module in weex DSL Now event moudle is avaiable in weex, use the module like this:

    <text onclick="click">testMyModule</text>

  module.exports = {
    methods: {
      click: function() {
        weex.requireModule('MyModule').printLog("I am a weex Module!");

# Register module


  • return(bool): register success
  • moduleName(String): module name
  • moduleClass(Class): the Java class of the module, which provide a constructor with an empty parameter.


WXSDKEngine.registerModule("picker", WXPickersModule.class);

# Javascript callback

If the module need implement a callback to javascript, you just add JSCallback argument to the method you want expose to javascript:

public void openURL(String url,JSCallback callback){
  //implement your module logic here
  Map<String,Object> resp = new HashMap();

At the javascript side, call the module with javascript function to receive callback data:

event.openURL("http://www.github.com",function(resp){ console.log(resp.result); });

# Component extension adaptation

# weex_sdk version >= v0.19+

# Abstract

The WXDomObject and Layout engines are sunk into WeexCore using C++, and the WXDomObject in Java code has been removed. The 0.19 version of the upgrade involves interface changes to WXComponent and WXDomObject.

# Migration guide

# setMeasureFunction migrate

The setMeasureFunction() method in WXDomObject was migrated to WXComponent:

protected void setMeasureFunction(final ContentBoxMeasurement contentBoxMeasurement);

See: com.taobao.weex.layout.ContentBoxMeasurement.java

Demo: WXText.java / setMeasureFunction()

Note:ContentBoxMeasurement only supports leaf nodes.

# WXComponent Interface change
# getDomObject [Delete]

Since the WXDomObject sinks to WeexCore, the WXComponent's getDomObject() method has been removed.

# Constructor [Parameter change]

The constructor of WXComponent removes the parameter of type WXDomObject, adds a parameter of type BasicComponentData, and the remaining parameters remain unchanged:

public WXComponent(WXSDKInstance instance, WXVContainer parent, int type, BasicComponentData basicComponentData);
public WXComponent(WXSDKInstance instance, WXVContainer parent, BasicComponentData basicComponentData);
# WXDomObject Interface change

You can't access and inherit WXDomObject using Java code, (the ImmutableDomObject.java has also been removed), some of the methods in WXDomObject have been migrated to WXComponent if you need to use them:

# WXDomObject.getType() -> WXComponent.getComponentType() [Migrate]

The getType() method in WXDomObject is used to get the type of Component (for example: list, div, text, img...). After migrating to WXComponent, it is renamed to:

public String getComponentType();
# Some methods for Layout results [Migrate]

Migrating from WXDomObject to WXComponent:

public float getCSSLayoutTop();
public float getCSSLayoutBottom();
public float getCSSLayoutLeft();
public float getCSSLayoutRight();
public float getLayoutWidth();
public float getLayoutHeight();

Remove two obsolete interfaces:

public float getLayoutY();
public float getLayoutX();

# weex_sdk version < v0.19

  1. Customize components must extend from WXComponent
  2. Use the @WXComponentProp(name = value(value is attr or style)) annotation to let the update of attribute or style be recognized automatically.
  3. The access levels of method must be public
  4. Customize can not be obfuscated by tools like ProGuard
  5. Component method with the annotation of @JSMethod can
  6. Weex params can be int, double, float, String, Map, List, Array
  7. Register your Component by WXSDKEngine.registerComponent

Refer to the following example

public class RichText extends WXComponent<TextView> {

    public RichText(WXSDKInstance instance, WXDomObject dom, WXVContainer parent) {
        super(instance, dom, parent);

    protected TextView initComponentHostView(@NonNull Context context) {
        TextView textView = new TextView(context);
        return textView;

    @WXComponentProp(name = "tel")
    public void setTel(String telNumber) {
        getHostView().setText("tel: " + telNumber);

Register your Component:

WXSDKEngine.registerComponent("richText", RichText.class);

Use this component in weex DSL:

    <richText tel="12305" style="width:200;height:100">12305</richText>

# Extend Component Method

WeexSDK (0.9.5+) support the component method that can be invoked for example:

public void focus(){
 //method implementation

after your registration for your own custom component, now you can call it in your js file.

  <mycomponent ref='mycomponent'></mycomponent>
  module.exports = {
    created: function() {

# Register component


  • return(bool): register success
  • type(String): component's name,such as div
  • class(Class): ComponentClass,called when init component
  • appendTree(bool): render option logic,default false
    • if true,render compoent tree one-time
    • if false,render component one by one


WXSDKEngine.registerComponent("video", WXVideo.class, false);


  • return(bool): register success
  • holder(IFComponentHolder): abstract factory designed for create Component, and SimpleComponentHolder is the a simple way to achieve IFComponentHolder.
  • appendTree: see registerComponent(type,class,appendTree)
  • names(String ...): component's name in front end template file


              new SimpleComponentHolder(
                      new WXText.Creator()

# Extend adapter

# ImagedownloadAdapter

Weex SDK has no image download capability, you need to implement IWXImgLoaderAdapter.

Refer to the following example

public class ImageAdapter implements IWXImgLoaderAdapter {

  public ImageAdapter() {

  public void setImage(final String url, final ImageView view,
                       WXImageQuality quality, WXImageStrategy strategy) {

    WXSDKManager.getInstance().postOnUiThread(new Runnable() {

      public void run() {
        if (TextUtils.isEmpty(url)) {
        String temp = url;
        if (url.startsWith("//")) {
          temp = "http:" + url;
        if (view.getLayoutParams().width <= 0 || view.getLayoutParams().height <= 0) {

# Set up various adapters

# ImageAdapter

Image adapter is responsible for loading images according to URLs. There are two types of image adapter:

  1. Loading a image to a view according to URL.
  2. Loading a image to a specified object according to URL.

In order to use image component, one must implement the first adapter, while the second adapter is optional.

# IWXImgLoaderAdapter

public interface IWXImgLoaderAdapter {
  void setImage(String url, ImageView view, WXImageQuality quality, WXImageStrategy strategy);
  • WXImageQuality that the quality of the picture variables, take the following values LOW, NORMAL, HIGH, ORIGINAL picture quality in turn higher. The default is LOW.
  • WXImageStrategy is an extension class that indicates whether the image can be cut (isClipping) sharpening (isSharpen) placeholder (placeHolder) and so on.

# IDrawableLoaderAdapter

This adapter is optional.

void setDrawable(String url, DrawableTarget drawableTarget, DrawableStrategy drawableStrategy);
  • DrawableTarget is a object into where will load an image. DrawableTarget is one of StaticTarget or AnimatedTarget.

# IWXHttpAdapter

Weex custom WXRequest and OnHttpListener, Native reload interface can be obtained from the Request URL, Header and other parameters, the network request can be completed through OnHttpListener callback notification. Weex provides the default network request: DefaultWXHttpAdapter, using HttpURLConnection for network requests.

The interface is defined as follows:

public interface IWXHttpAdapter {
	void sendRequest(WXRequest request, OnHttpListener listener);

# WXRequest

  • WXRequest defines the parameters related to the network request, the request method, the request body, and the timeout time. Weex default timeout is 3s.

# OnHttpListener

 interface OnHttpListener {

     * start request
    void onHttpStart();

     * headers received
    void onHeadersReceived(int statusCode,Map<String,List<String>> headers);

     * post progress
     * @param uploadProgress
    void onHttpUploadProgress(int uploadProgress);

     * response loaded length (bytes), full length should read from headers (content-length)
     * @param loadedLength
    void onHttpResponseProgress(int loadedLength);

     * http response finish
     * @param response
    void onHttpFinish(WXResponse response);

# IWXUserTrackAdapter

Weex related performance data (first screen loading time, JS-Native communication time, dom update time, etc.) and other general information (JSLib file size, Weex SDK version number, etc.).

public interface IWXUserTrackAdapter {
	void commit(Context context, String eventId, String type, WXPerformance perf, Map<String, Serializable> params);

Native implementation interface can be obtained through WXPerformance and params corresponding information.

# IActivityNavBarSetter

Weex provided the ability of navigation through WXNavigatorModule which relys on IActivityNavBarSetter.


WXSDKEngine.setActivityNavBarSetter(new IActivityNavBarSetter(){});   

# IWXStorageAdapter

Weex provided the ability of local storage through WXStorageModule which depends on IWXStorageAdapter. One can use DefaultWXStorage as the default implementation of IWXStorageAdapter.

# IWXJSExceptionAdapter

IWXJSExceptionAdapter is used to handle weex exception.

  • DownLoadException
  • WhiteSceenException
  • JSException
  • DownGradeException
public interface IWXJSExceptionAdapter {
  void onJSException(WXJSExceptionInfo exception);


WXSDKEngine.setJSExcetptionAdapter(new TestExceptionAdapter());

# Proguard Rules

If you want to using proguard to protect your source code, please add the following rules to your profile:

-keep class com.taobao.weex.WXDebugTool{*;}
-keep class com.taobao.weex.devtools.common.LogUtil{*;}
-keepclassmembers class ** {
  @com.taobao.weex.ui.component.WXComponentProp public *;
-keep class com.taobao.weex.bridge.**{*;}
-keep class com.taobao.weex.dom.**{*;}
-keep class com.taobao.weex.adapter.**{*;}
-keep class com.taobao.weex.common.**{*;}
-keep class * implements com.taobao.weex.IWXObject{*;}
-keep class com.taobao.weex.ui.**{*;}
-keep class com.taobao.weex.ui.component.**{*;}
-keep class com.taobao.weex.utils.**{
    public <fields>;
    public <methods>;
-keep class com.taobao.weex.view.**{*;}
-keep class com.taobao.weex.module.**{*;}
-keep public class * extends com.taobao.weex.common.WXModule{*;}
-keep public class * extends com.taobao.weex.ui.component.WXComponent{*;}
-keep class * implements com.taobao.weex.ui.IExternalComponentGetter{*;}
Last Updated: 8/15/2022
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