Integrate a PhP function with JQuery - Check if Us

问题:

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 user simply gets a message that the user already exists and can change the name.

Looks like this :

PHP CODE:

<?php

$link = mysqli_connect("localhost","root","","data1") or die("Error " . mysqli_error($link));
$usercheck = "csdcsdsdf";

$sanitizeduser= filter_var($usercheck, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW);

$result = $link->query("SELECT username FROM users WHERE username = '".$sanitizeduser."' ");

$row_cnt = $result->num_rows;    
if($row_cnt>0){     
    echo "User Exists";
}else{      
    echo "No User found";
}

?>

I'm using a predefined jquery code (this script : http://jqueryvalidation.org/)'

part of my jquery code to validate names :

names: function(value, element) {
            return this.optional(element) || /^\w+$/.test(value);
        },

Full Jquery code :

file 1 : http://jsfiddle.net/EjSbd/1/ (script.js)

file 2 : http://jsfiddle.net/qM4Uz/1/ (jquery.validate.js)

回答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("Enter at least {0} characters"),
                remote: $.format("{0} is already in use")
            },
            slcchild:  {
                required: "Select A node",
                remote: $.format("{0} is not empty")
            }
        }
    });

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/

回答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/

回答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:

function changeArea()
    {
    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();