Integrate A Php Function With Jquery - Check If User Already Exists In Db

i have a php code to check if a user already exists in my db , but i would like it to go through jquery first . This way instead of getting an error message on a new page , the use

Solution 1:

If you are using jQuery validation plugin then here is the solution. This is active code. you need to use remote: . This is my existing code. This will help you to get idea.

$("form#form-join-1").validate({rules: {
            sponsorID: {
                required:true,
                minlength:5,
                remote:"ajax.php"
            },
            slcchild: {
                required :true,
                remote : {
                    url:"ajax.php",
                    type:"post",
                    data: {
                        action :'child-validation',
                        parent_node :function(){
                            return$('input#sponsorID').val();
                        }
                    }
                }
            }
        },messages: {
            sponsorID:  {
                required:"Enter a Sponsor ID",
                minlength:$.format("Enteratleast {0} characters"),
                remote:$.format("{0} isalreadyinuse")
            },
            slcchild:  {
                required:"Select A node",
                remote:$.format("{0} isnotempty")
            }
        }
    });

Here is complete guideline. Following this link. They have example code. http://imamiscool.wordpress.com/2009/06/29/check-email-availability-using-jquery%E2%80%99s-ajax-part-2-easy-way/

Solution 2:

Try this, You need to add remote: "usernamecheck.php" Assumed your php file name is usernamecheck.php

username: {
  minlength:5,
  maxlength:20,
  required:true,
  wordonly:true,
  remote:"usernamecheck.php"
},

Ref: http://jqueryvalidation.org/category/methods/

Solution 3:

One of the easier ways is to use one of jQuery's Ajax functions, .load()

So first you make an HTML div where you want your dynamically generated content to be:

<div id="area_to_load_at">
    This text will be replaced when JS runs changeArea()
</div>

Next you make a Javascript function that's just for changing the div:

functionchangeArea()
    {
    var loadTo = "#area_to_load_at";
    var loadFrom = "your_file_that_checks_if_the_username_is_taken.php";

    $(loadTo).load(loadFrom); 
    }

Then anywhere in the Javascript where you want it, like right after your validation, just call:

changeArea();