在JSF Ajax响应XML插入自定义标签 [英] Inserting custom tag in JSF Ajax response XML
问题描述
Consoder以下code：
＆LT; H：的commandButton值=做行动=＃{testBacking.do}＆GT;
＆LT; F：AJAX执行=@所有渲染=@所有监听器=＃{testBacking.listener}/＆GT;
＆LT; / H：的commandButton＆GT;
我想有（与基于服务器的逻辑值）的自定义标签，在Ajax响应XML，类似如下：
＆LT; isValidationFailed＆GT;真＆LT; / isValidationFailed＆GT;
我可以用这个数据来重新启用按钮（被禁用时阿贾克斯开始，以避免重复点击）如果验证失败。
我怎样才能做到这一点（preferably不使用任何JSF第三方库）？
编辑：
这个例子code，更precisely，应该是这样的：
＆LT; H：的commandButton ID =myButton的值=做行动=＃{testBacking.do}＆GT;
＆LT; F：AJAX执行=ID1渲染=ID2 myButton的监听器=＃{testBacking.listener}/＆GT;
＆LT; / H：的commandButton＆GT;
这是唯一可能与自定义的 PartialViewContext 您使用的 PartialViewContextFactory 。自定义 PartialViewContext 应依次返回一个自定义的 PartialResponseWriter 的<一个href="http://docs.oracle.com/javaee/6/api/javax/faces/context/PartialViewContext.html#getPartialResponseWriter%28%29"相对=nofollow> PartialViewContext＃getResponseWriter（） 。在此自定义 PartialResponseWriter ，你应该能够扩展添加到XML响应通过调用<一href="http://docs.oracle.com/javaee/6/api/javax/faces/context/PartialResponseWriter.html#startExtension%28java.util.Map%29"相对=nofollow> startExtension（） 和<一href="http://docs.oracle.com/javaee/6/api/javax/faces/context/PartialResponseWriter.html#endExtension%28%29"相对=nofollow> endExtension（） 在<一个href="http://docs.oracle.com/javaee/6/api/javax/faces/context/PartialResponseWriter.html#endDocument%28%29"相对=nofollow> 调用endDocument（） 。是这样的：
@覆盖
公共无效调用endDocument（）抛出IOException异常{
地图＆LT;字符串，字符串＆GT;属性=新的HashMap＆LT;字符串，字符串＆GT;（）;
attributes.put（名1，值1）;
attributes.put（名2，值2）;
startExtension（属性）;
写（Lorem存有）;
endExtension（）;
super.endDocument（）;
}
这将随后结束在XML响应，
＆LT;扩展名1 =值1名称2 =值2＆GT; Lorem存有＆LT; /扩展＆GT;
这是可用，穿越由 data.responseXML 在 jsf.ajax.addOnEvent（）的功能。
下面是一个完整的开球例如如何，你可以在您的特定情况下使用它：
MyPartialViewContextFactory ，它提供了自定义的局部视图方面：
公共类MyPartialViewContextFactory扩展PartialViewContextFactory {
私人PartialViewContextFactory包裹;
公共MyPartialViewContextFactory（PartialViewContextFactory包裹）{
this.wrapped =包裹;
}
@覆盖
公共PartialViewContext getPartialViewContext（FacesContext的上下文）{
返回新MyPartialViewContext（wrapped.getPartialViewContext（上下文））;
}
}
MyPartialViewContext ，它提供了自定义的部分反应作家：
公共类MyPartialViewContext扩展PartialViewContextWrapper {
私人PartialViewContext包裹;
私人PartialResponseWriter作家;
公共MyPartialViewContext（PartialViewContext包裹）{
this.wrapped =包裹;
this.writer =新MyPartialResponseWriter（wrapped.getPartialResponseWriter（））;
}
@覆盖
公共PartialResponseWriter getPartialResponseWriter（）{
返回作家;
}
@覆盖
公共无效setPartialRequest（布尔isPartialRequest）{
wrapped.setPartialRequest（isPartialRequest）;
}
@覆盖
公共PartialViewContext getWrapped（）{
返回包裹;
}
}
MyPartialResponseWriter 这将写入＆LT;扩展ID =myextension＆GT; 用身体为JSON）：
公共类MyPartialResponseWriter扩展PartialResponseWriter {
公共MyPartialResponseWriter（ResponseWriter包裹）{
超（包裹）;
}
@覆盖
公共无效调用endDocument（）抛出IOException异常{
startExtension（Collections.singletonMap（ID，myextension））;
写（{\validationFailed \：+ FacesContext.getCurrentInstance（）isValidationFailed（）+}）; //考虑一个JSON序列，如谷歌GSON。
endExtension（）;
super.endDocument（）;
}
}
要让它运行，在如下注册工厂faces-config.xml中：
＆LT;工厂＆GT;
<partial-view-context-factory>com.example.MyPartialViewContextFactory</partial-view-context-factory>
＆LT; /工厂＆GT;
下面是如何访问，分析和使用＆LT;扩展ID =myextension＆GT; 在 jsf.ajax.addOnEvent（ ）：
jsf.ajax.addOnEvent（功能（数据）{
如果（data.status ==成功）{
变参= JSON.parse（data.responseXML.getElementById（myextension）firstChild.nodeValue。）;
如果（args.validationFailed）{
// ...
}
其他 {
// ...
}
}
}）;
然而，特定的功能性需求，可以在不同的，可能更简单，方式实现。只是让Ajax请求更新按钮本身，让按钮的禁用属性评估真时，有一个成功的回传的方式
＆LT; H：的commandButton ID =myButton的值=做行动=＃{testBacking.do}
禁用=＃{facesContext.postback而不是facesContext.validationFailed}＆GT;
＆LT; F：AJAX执行=ID1渲染=@这个ID2监听器=＃{testBacking.listener}/＆GT;
＆LT; / H：的commandButton＆GT;
Consoder the following code:
<h:commandButton value="do" action="#{testBacking.do}">
<f:ajax execute="@all" render="@all" listener="#{testBacking.listener}"/>
</h:commandButton>
I want to have a custom tag (with value based on server logic), in the Ajax response XML, something like the following:
<isValidationFailed> true </isValidationFailed>
I can use this data to re-enable the button (which was disabled when Ajax begin, to avoid double clicks) if validation is failed.
How can I achieve this (preferably without using any JSF 3rd party libraries)?
EDIT:
The example code, more precisely, should be like this:
<h:commandButton id="myButton" value="do" action="#{testBacking.do}">
<f:ajax execute="id1" render="id2 myButton" listener="#{testBacking.listener}"/>
</h:commandButton>
This is only possible with a custom PartialViewContext which you load into your JSF application using a PartialViewContextFactory. The custom PartialViewContext should in turn return a custom PartialResponseWriter on PartialViewContext#getResponseWriter(). In this custom PartialResponseWriter, you should be able to add extensions to the XML response by calling startExtension() and endExtension() in endDocument(). Something like:
@Override
public void endDocument() throws IOException {
Map<String, String> attributes = new HashMap<String, String>();
attributes.put("name1", "value1");
attributes.put("name2", "value2");
startExtension(attributes);
write("lorem ipsum");
endExtension();
super.endDocument();
}
This will then end up in the XML response as
<extension name1="value1" name2="value2">lorem ipsum</extension>
This is available and traversable by data.responseXML in jsf.ajax.addOnEvent() function.
Here's a full kickoff example how you could utilize it in your particular case:
MyPartialViewContextFactory which provides the custom partial view context:
public class MyPartialViewContextFactory extends PartialViewContextFactory {
private PartialViewContextFactory wrapped;
public MyPartialViewContextFactory(PartialViewContextFactory wrapped) {
this.wrapped = wrapped;
}
@Override
public PartialViewContext getPartialViewContext(FacesContext context) {
return new MyPartialViewContext(wrapped.getPartialViewContext(context));
}
}
MyPartialViewContext which provides the custom partial response writer:
public class MyPartialViewContext extends PartialViewContextWrapper {
private PartialViewContext wrapped;
private PartialResponseWriter writer;
public MyPartialViewContext(PartialViewContext wrapped) {
this.wrapped = wrapped;
this.writer = new MyPartialResponseWriter(wrapped.getPartialResponseWriter());
}
@Override
public PartialResponseWriter getPartialResponseWriter() {
return writer;
}
@Override
public void setPartialRequest(boolean isPartialRequest) {
wrapped.setPartialRequest(isPartialRequest);
}
@Override
public PartialViewContext getWrapped() {
return wrapped;
}
}
MyPartialResponseWriter which writes <extension id="myextension"> with the body as JSON):
public class MyPartialResponseWriter extends PartialResponseWriter {
public MyPartialResponseWriter(ResponseWriter wrapped) {
super(wrapped);
}
@Override
public void endDocument() throws IOException {
startExtension(Collections.singletonMap("id", "myextension"));
write("{\"validationFailed\": " + FacesContext.getCurrentInstance().isValidationFailed() + "}"); // Consider a JSON serializer, like Google Gson.
endExtension();
super.endDocument();
}
}
To get it to run, register the factory as follows in faces-config.xml:
<factory>
<partial-view-context-factory>com.example.MyPartialViewContextFactory</partial-view-context-factory>
</factory>
Here's how you can access, parse and use the <extension id="myextension"> in your jsf.ajax.addOnEvent():
jsf.ajax.addOnEvent(function(data) {
if (data.status == "success") {
var args = JSON.parse(data.responseXML.getElementById("myextension").firstChild.nodeValue);
if (args.validationFailed) {
// ...
}
else {
// ...
}
}
});
However, your particular functional requirement can be achieved in a different, likely simpler, manner. Just let the ajax request update the button itself and let the button's disabled attribute evaluate true when there's means of a successful postback.
<h:commandButton id="myButton" value="do" action="#{testBacking.do}"
disabled="#{facesContext.postback and not facesContext.validationFailed}">
<f:ajax execute="id1" render="@this id2" listener="#{testBacking.listener}"/>
</h:commandButton>
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