Using Ajax in Grails

Grails has a good integration of Ajax, which describes the use of jquery's Getjson method for asynchronous Ajax transmission.

Steps to use:

• Introduction of jquery (. GSP page introduced Jquery.js)

<script type= "Text/javascript" src= "${resource (dir: ' Assets/js ', File: ' Jquery.js ')}" ></script>

• Add Ajax calling methods in Javascript scripts

   function Isproductionnameexist (o) {       var productName = "Test";       var mode = "Test";           $.getjson ("Isproductionnameexist",  //action in controller                   {productname:productname,  //params pass to Action, you can use ' null ' when no params    mode:mode},                   function (data) {           //* Call-back function when Ajax CA ll complete                       alert (data.isexist);}                   );       }   

　　

• Action in Controller

  Def isproductionnameexist () {      def productName = Params.productname  
      def mode = Params.mode      def status = "Y"       def ret = [Isexist:status]      render ret as JSON  }

• Trigger JS function

<g:textfield name= "name" onblur= "Isproductionnameexist (This)"/>

　　

Problems that may exist:

1. Cannot trigger action in controller

The ID parameter in the params affects, as follows, the id attribute

<g:textfield id= "${xxxinstance.attr}" name= "name" onblur= "Isproductionnameexist (This)"/>

Another grails automatically generated additions and deletions when the page jumps will be implicitly passed the ID, will also cause Ajax can not trigger action

2. Garbled characters

The data in the controller/action to get Ajax is garbled, which is caused by different browsers dealing with Ajax requests. For example: In Ajax calls, IE always uses the client OS default encoding, such as GB2312, and Firefox always uses UTF-8 encoding.

To prevent the browser from encoding the data, the data is encoded with a function before the data is transmitted, and the server decodes the data.

Example:

$.getjson ("Isproductionnameexist",            {productname:encodeuricomponent (productName)},          function (data) {                         });  Def isproductionnameexist () {      def productName = Params.productName.decodeURL ()       def status = "Y"       def ret = [ Isexist:status]      render ret as JSON  }

　　

Using Ajax in Grails