dojo.formToJson

Available:since V0.9

Helper function for converting a HTML form to a JSON string

Introduction

This function is one of many helpers used by the dojo Xhr subsystem for handling AJAX style requests. This particular function takes a HTML form node and converts the form elements into a JSON string. This function is identical to doing the operation:

dojo.toJson(dojo.formToObject(“formid”));

You can refer to the dojo.formToObject documentation for more details.

Usage

Usage is simple and straightforward, you pass the form node or the string id of a form node to convert. The function will hand back a JSON string of the name/value pairs from the form elements.

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<script type="text/javascript">
  var formId = "myId";
  var formJson = dojo.formToJson(formId);

  //Assuming a form of:
  // <form id="myform">
  //    <input type="text" name="field1" value="value1">
  //    <input type="text" name="field2" value="value2">
  //    <input type="button" name="someButton" value="someValue">
  // </form>
  //
  //The structure of formJson will be:
  // {"field1":"value1","field2":"value2"}
  //Note the button was skipped.
</script>

Examples

Example 1: Using formToJson to create an JSON version of a form

<script>
  function convertForm() {
    dojo.connect(dijit.byId("convertForm"), "onClick", function(){
       var formJson = dojo.formToJson("myform");

       //Attach it into the dom as pretty-printed text.
       dojo.byId("formObject").innerHTML = formJson;
    });
  }
  dojo.addOnLoad(convertForm);
</script>
<button id="convertForm" dojoType="dijit.form.Button">Click to convert the form to an object</button><br><br>
<b>The FORM</b><br><br>
<form id="myform">
   <input type="text" name="field1" value="value1">
   <input type="text" name="field2" value="value2">
   <input type="button" name="someButton" value="someValue">
</form>
<br><br>
<b>The form as JSON:</b>
<pre id="formObject"></pre>

Example 2: Using formToJson to create a JSON version of a form with dijit widgets

<script>
  dojo.require("dijit.form.TextBox");
  dojo.require("dijit.form.Button");
  function convertFormDigits() {
    dojo.connect(dijit.byId("convertFormDigits"), "onClick", function(){
       var formJson=  dojo.formToJson("myform2");

       //Attach it into the dom as pretty-printed text.
       dojo.byId("formObject2").innerHTML = formJson;
    });
  }
  dojo.addOnLoad(convertFormDigits);
</script>
<button id="convertFormDigits" dojoType="dijit.form.Button">Click to convert the form to an object</button><br><br>
<b>The FORM</b><br><br>
<form id="myform2">
   <input type="text" dojoType="dijit.form.TextBox" name="field1" value="value1">
   <input type="text" dojoType="dijit.form.TextBox" name="field2" value="value2">
   <button dojoType="dijit.form.Button" name="someButton" value="someValue">someValue</button>
</form>
<br><br>
<b>The form as JSON:</b>
<pre id="formObject2"></pre>
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