How do you pass a JavaScript variable to your Groovy controller?

问题

I have been searching on Google for a really good while, and I cannot find a solution to this problem. I am trying to access a JavaScript variable from my GSP file in my Groovy controller, but I can't find out how to do this.

Example:

//JavaScript stuff
<script>
    function validateForm(){
         var ret = false
    }
</script>

//Groovy controller stuff
def myAction = {
    println params.ret
}

How do I achieve something similar to this?

回答1:

Two ways to pass a variable to the controller:

1. Ajax
2. Form submit

Ajax

• Use remoteFunction

  ${remoteFunction(controller: 'actionsController' , action: 'implementNewPixel', params: '\'ret=\' + ret')} 
  

• Use Ajax

  var ret = false;
  jQuery.ajax({
      url: "${createLink(controller: 'actionsController', action: 'implementNewPixel')}",
      data: "ret=" + ret,
      success: function (data) {
          alert(data);
      }
  });
  

etc.

Form submit

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script>
    var ret;
    function validateForm(){
        ret = false;
    }

    jQuery(function () {
        jQuery("[name='jftForm']").submit(function () {
            jQuery("[name='ret']").val(ret);
        });
    });
</script>

<g:form name="jftForm" controller="actionsController" action="implementNewPixel">
    ...
    <g:hiddenField name="ret" value=""/>
    <g:submitButton name="submit" value="Submit"/>
</g:form>

回答2:

Look at the documentaton.

params: '\'ret=\' + ret'

来源：https://stackoverflow.com/questions/18093278/how-do-you-pass-a-javascript-variable-to-your-groovy-controller