Wait Until Multiple Functions, Which May Or May Not Call Ajax Internally, Are Complete In JQuery?

I am currently validating a few inputs clientside. When the user submits the form, I want to check the values for the form inputs, and then do something once all the checks are com

Solution 1:

I don't see you validate_input function return anything. If you want to wait, you need to return a promise, so that you don't pass undefined to $.when():

function validate_input(input){
    var value=input.val();
    if (value.length<4){
        return …; //code to execute if input is too short
    } else {
        return $.ajax({
 //     ^^^^^^
            …
        });
    }
}

Solution 2:

var inputsLength = 0, // or maybe set it to $('form input').length
    inputsReady = 0;
function checkInputsValidation(){
    if (++inputsReady === inputsLength) YOURSALLINPUTSAREVALIDFUNCTION();
}
function validate_input(input){
    inputsLength++; // remove it if you already set inputsLength
    // blablabla
    $.ajax({             
        type: 'get',
        url: check_input_url,
        data: input.serialize(),
        success: function(data){
            if (data=="invalid") {
                //code to execute if invalid
            } else {
                checkInputsValidation();
            }
        }
    });
}

Solution 3:

UPDATE: i just updated my answer. it is more likely to fit your needs now. i've added a parameter to the callback function.

use callbacks with anonymous functions and chain them:

1. add a parameter for the callback function and the callback function call:

function validate_input(input, callback){
    value=input.val();
    if (value.length<4){
        //code to execute if input is too short
        callback(false);
    }
    else {
        $.ajax({             
            type: 'get',
            url: check_input_url,
            data: input.serialize(),
            success: function(data){
                if (data=="invalid") {
                    //code to execute if invalid
                    callback(false);
                } else {
                    //code to execute if valid
                    callback(true);
                }
            }
        });
    }
}

2. when calling your function multiple times, chain it with anonymous functions (which are executed after success in your $.ajax-request has been fired):

$('form').submit(function() {
    var input1 = $('form #input1');
    var input2 = $('form #input2');

    //validate both input values
    validate_input(input1, function(result){
        if(result == true)
        {
             validate_input(input2, function(result){
                 if(result == true)
                 {
                    //wait until all validation complete to execute code here
                 }
                 else
                 {
                    return false;
                 }
             });
        }
        else
        {
            return false;
        }
    });
});