dojo ajax post 和 get 的方法的使用, formData 提交 Enumeration＜String＞ enumx = request.getParameterName()

dojo ajax post 的方法的使用

dojo 是非常强大的前端开发平台，对标签、JS 都有着完善的操作机制，以下举例 dojo 向服务器 post 和 get 的实例：

 

1、数据来自 from 的 dojo post 操作

 

function sendForm(){
  var form = dojo.byId("myform");

  dojo.connect(form, "onsubmit", function(event){
    // Stop the submit event since we want to control form submission.
    dojo.stopEvent(event);

    // The parameters to pass to xhrPost, the form, how to handle it, and the callbacks.
    // Note that there isn't a url passed.  xhrPost will extract the url to call from the form's
    //'action' attribute.  You could also leave off the action attribute and set the url of the xhrPost object
    // either should work.
    var xhrArgs = {
      form: dojo.byId("myform"),
      handleAs: "text",
      load: function(data){
        dojo.byId("response").innerHTML = "Form posted.";
      },
      error: function(error){
        // We'll 404 in the demo, but that's okay.  We don't have a 'postIt' service on the
        // docs server.
        dojo.byId("response").innerHTML = "Form posted.";
      }
    }
    // Call the asynchronous xhrPost
    dojo.byId("response").innerHTML = "Form being sent..."
    var deferred = dojo.xhrPost(xhrArgs);
  });
}
dojo.ready(sendForm);

 

 

 

2、数据直接在 js 内构建的 dojo post 操作

 

function sendText(){
  var button = dijit.byId("submitButton2");

  dojo.connect(button, "onClick", function(event){
    // The parameters to pass to xhrPost, the message, and the url to send it to
    // Also, how to handle the return and callbacks.
    var xhrArgs = {
      url: "postIt",
      postData: "Some random text",
      handleAs: "text",
      load: function(data){
        dojo.byId("response2").innerHTML = "Message posted.";
      },
      error: function(error){
        // We'll 404 in the demo, but that's okay.  We don't have a 'postIt' service on the
        // docs server.
        dojo.byId("response2").innerHTML = "Message posted.";
      }
    }
    dojo.byId("response2").innerHTML = "Message being sent..."
    // Call the asynchronous xhrPost
    var deferred = dojo.xhrPost(xhrArgs);
  });
}
dojo.ready(sendText);

 

 

 

 

 

3、数据以 json 方式提交的 dojo post 操作

 

function sendText(){
  var button = dijit.byId("submitButton2");

  dojo.connect(button, "onClick", function(event){
    // The parameters to pass to xhrPost, the message, and the url to send it to
    // Also, how to handle the return and callbacks.
    var xhrArgs = {
      url: "{{baseUrl}}dojo/dojo.js",
      postData: dojo.toJson({key1:"value1",key2:{key3:"value2"}}),
      handleAs: "text",
      load: function(data){
        dojo.byId("response2").innerHTML = "Message posted.";
      },
      error: function(error){
        // We'll 404 in the demo, but that's okay.  We don't have a 'postIt' service on the
        // docs server.
        dojo.byId("response2").innerHTML = "Message posted.";
      }
    }
    dojo.byId("response2").innerHTML = "Message being sent..."
    // Call the asynchronous xhrPost
    var deferred = dojo.xhrPost(xhrArgs);
  });
}
dojo.ready(sendText);

 

postData 以 json 或 text 传入，尤其是针对传入参数结构不定的情况，service 获取参数 java 代码如下：

 

    Enumeration<String> enumeration = request.getParameterNames();
    while (enumeration.hasMoreElements() == true)
    {
      String strParameterName = enumeration.nextElement().toString();
      String strValue = request.getParameter(strParameterName);
      ............
    }

 

 

 

4.以参数及变量形式的 dojo 提交

 

  function sendText();
  {
    var xhrArgs = {
      url : "/service/path",
      content : {
        name : 'your name',
        data1 : 'data1',
        data2 : 'data2',
        data3 : 'data3',
      },
      handleAs : "text",
      // 同步,默认 false
      sync: true,
      load : function(data)
      {
        console.debug(data);
      },
      error : function(error)
      {
        console.debug(data);
      }
    }
    var deferred = dojo.xhrPost(xhrArgs);
  }

 

上面全是 post 方式，get 方式几乎一样

 

 

dojo.ready(function(){
  // Look up the node we'll stick the text under.
  var targetNode = dojo.byId("licenseContainer");

  // The parameters to pass to xhrGet, the url, how to handle it, and the callbacks.
  var xhrArgs = {
    url: "{{dataUrl}}dojo/LICENSE",
    handleAs: "text",
    load: function(data){
      // Replace newlines with nice HTML tags.
      data = data.replace(/\n/g, "<br>");

      // Replace tabs with spaces.
      data = data.replace(/\t/g, "   ");

      targetNode.innerHTML = data;
    },
    error: function(error){
      targetNode.innerHTML = "An unexpected error occurred: " + error;
    }
  }

  // Call the asynchronous xhrGet
  var deferred = dojo.xhrGet(xhrArgs);
});

 

通过以下命令将字符串转化为 JS 对象

 

JSON.parse('{}');              // {}
JSON.parse('true');            // true
JSON.parse('"foo"');           // "foo"
JSON.parse('[1, 5, "false"]'); // [1, 5, "false"]
JSON.parse('null');            // null

将 JS 对象转化为字符串

 

 

JSON.stringify({});                  // '{}'
JSON.stringify(true);                // 'true'
JSON.stringify('foo');               // '"foo"'
JSON.stringify([1, 'false', false]); // '[1,"false",false]'
JSON.stringify({ x: 5 });            // '{"x":5}'

 

dojo 提交参数中，有一项 handleAs:"text"，即表示返回信息的类型，若需要返回的是 json，则需要把 handleAs:"text" 改为 handleAs:"json"，这样的话，JSON.parse() 将正确转换 string 串为 object 类型。

 

 

 

以上参考来自

http://dojotoolkit.org/reference-guide/1.10/dojo/xhrPost.html
https://dojotoolkit.org/reference-guide/1.10/dojo/xhrGet.html
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify

 

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