从Javascript调用Wicket 6代码并返回值 [英] Call Wicket 6 Code from Javascript and return value

问题描述

在此示例中，我设法使用选项A从Javascript调用了Wicket 6 Java代码: https://stackoverflow.com/a/42612027/1047418

I have managed to call my Wicket 6 Java code from Javascript using option A in this example: https://stackoverflow.com/a/42612027/1047418

但是，我找不到用于将数据从Java端返回给JavaScript的示例(生成的JavaScript回调函数甚至都不包含return语句).如何实现?

However, I have not been able to find examples for returning data from the Java side back to JavaScript (the generated JavaScript callback function does not even include a return statement). How can this be achieved?

我没有试图在Java中设置属性，正如我已经解释的那样，从JavaScript调用Wicket并不是这里的问题.由于Ajax请求，我试图将Wicket的JSON对象返回给浏览器.

I am not trying to set an attribute in Java and as I've already explained, calling Wicket from JavaScript is not the problem here. I am trying to return a JSON object from Wicket back to the browser as a result of an Ajax request.

Edit2:按照martin-g的示例，我整理了这个工作示例...

Following martin-g's examples I cobbled up this working example...

Java

public class MyAjaxBehaviour extends AbstractDefaultAjaxBehavior {

    @Override
    protected void onComponentTag(ComponentTag tag) {
        super.onComponentTag(tag);
        tag.put("aprachatcallbackurl", getCallbackUrl());
    }

    @Override
    protected void updateAjaxAttributes(AjaxRequestAttributes attributes) {
        super.updateAjaxAttributes(attributes);
        attributes.setDataType("json");
        attributes.setWicketAjaxResponse(false);
    }

    @Override
    protected void respond(AjaxRequestTarget target) {
        getComponent().getRequestCycle().replaceAllRequestHandlers(
            new TextRequestHandler("application/json", "UTF-8", "{...JSON GOES HERE...}));
    }
}

JavaScript

JavaScript

var mySuccessCallback = function(param1, param2, data, statusText) {
    // Data contains the parsed JSON object from MyAjaxBehaviour.respond(...)
    ...
}

var myFailureCallback = function() {
    ...
}

Wicket.Ajax.get({
    "u": callbackUrl,
    "dt": "json",
    "wr": false,
    "sh": [mySuccessCallback],
    "fh": [myFailureCallback]
});

主要问题在于，"Wicket 7参考"错误地指示在JavaScript调用中使用"wr"而不是"dt". :)

Main problem as that the Wicket 7 Reference incorrectly instructs to use "wr" instead of "dt" in the JavaScript call. :)

推荐答案

我认为您可以以更简单的方式做到这一点！

I think you can do it in a simpler way!

Wicket Ajax API只是:Wicket.Ajax.ajax({...}).您需要在服务器端进行的准备工作就是保存回调网址，例如通过将其全局保存在window对象或HTML元素的属性(data-the-url)中.

Wicket Ajax API is just: Wicket.Ajax.ajax({...}). All you need to prepare at the server side is to save the callback url, e.g. by saving it globally in the window object or in HTML element's attributes (data-the-url).

public class CallFromJavascriptBehavior extends AbstractDefaultAjaxBehavior {
   @Override
   protected void respond(AjaxRequestTarget target) {
      final StringValue parameterValue = RequestCycle.get().getRequest().getQueryParameters().getParameterValue("yourName");
      System.out.println(String.format("Hello %s", parameterValue.toString()));

      // write anything to the WebResponse and then consume it in the JS success handler. See below
   }

   @Override
   public void onComponenntTag(ComponenntTag tag, Component component) {
       super.onComponenntTag(tag, component);
       tag.put("data-the-url", getCallbackUrl());
   }
}

然后在您的JS代码中可以执行以下操作:

Then in your JS code you can do:

var callbackUrl = jQuery("#theElementId").data("the-url");
Wicket.Ajax.get({"u": callbackUrl, "sh":[successHandler], "fh": [failureHandler] });

其中successHandler和failureHandler是内联(例如function(...) {})或其他地方定义的JS函数.

Where successHandler and failureHandler are JS functions defined inline (e.g. function(...) {}) or elsewhere.

更多文档，您可以在以下位置找到: https://ci.apache.org/projects/wicket/guide/7.x/single.html#_ajax_request_attributes_and_call_listeners

More documentation you can find at: https://ci.apache.org/projects/wicket/guide/7.x/single.html#_ajax_request_attributes_and_call_listeners

博客文章，其中包含完整示例，网址为 http://wicketinaction. com/2012/07/wicket-6-javascript-improvements/

A blog article with an complete example at http://wicketinaction.com/2012/07/wicket-6-javascript-improvements/

这篇关于从Javascript调用Wicket 6代码并返回值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！