CODEWITHSUNDEEP
javascriptphpajax
erol_smsr
erol_smsr

Reputation: 1496

I can't seem to make this if statement work in Javascript :S

I've got two functions which both get the user_id of a user. One function gets the session user_id and the other function gets the id that's in the url like so: profile.html?id=123. Here's the code:

// get URL parameter (user_id)
        function GetURLParameter(sParam) {
            var sPageURL = window.location.search.substring(1);
            var sURLVariables = sPageURL.split('&');
            for (var i = 0; i < sURLVariables.length; i++) 
            {
                var sParameterName = sURLVariables[i].split('=');
                if (sParameterName[0] == sParam) 
                {
                    return sParameterName[1];
                }
            }
        }

        // get URL parameter (user_id) function call
        url_user_id = GetURLParameter('id');
        alert("url user id = " + url_user_id); 

        // get SESSION user_id
        function get_session_user_id() {
            $.post( "http://localhost/snapll_back/account/session_user_id.php",
            function(info) {        
                if(info != "Something went wrong. ERROR{1_RAI_ERROR}") {
                    session_user_id = info;
                    alert("session user id = " + session_user_id);

                    // hide the follow button if this me is owned by the viewer
                    if(session_user_id == url_user_id) {
                        $("#follow_button").hide();
                    }

                    // THE QUESTION ON S.O. IS ABOUT THIS IF STATEMENT
                    // give the url_user_id variable the value of the session_user_id variable if not set correctly via the URL
                    if(url_user_id == 'undefined' || url_user_id == "" || url_user_id == null) {
                        url_user_id = session_user_id;  
                    }
                }
                else {
                    $('#warning').html(info).fadeIn(200);
                    setTimeout(function () {
                       window.location.href = "index.html";
                    }, 2000);
                }
            });
            return false;   
        }

        get_session_user_id();

So, what I need to do is to check if the variable 'url_user_id' is set. If not, the url_user_id should get the same value as the variable 'session_user_id'. However, for some reason, this doesn't happen. I have the if statement in the code above in this part:

if(url_user_id == 'undefined' || url_user_id == "" || url_user_id == null) {
    url_user_id = session_user_id;  
}

I use the url_user_id variable to get the username of the current profile the user is viewing. Here's the function that gets the username:

// get username function
        function get_username() {
            $.post( "http://localhost/snapll_back/account/username.php?id="+url_user_id,
            function(info) {        
                if(info != "Something went wrong. ERROR{1_RAI_ERROR}") {
                    $("#main_header_username").html(info);
                }
                else {
                    $('#warning').html(info).fadeIn(200);
                }
            });
            return false;      
        }

When I visit the page with the url like this: www.mywebsite.com/profile.php?id= (so if I specify no id in the URL) the variable url_user_id, which normally gets its value from the URL, should get the value of the variable session_user_id. Currently, I keep getting 'undefined' as the value of url_user_id and the if statement doesn't seem to notice that value to take action.

Who knows how I can fix this?

+=======================================================================================+ EDIT

I'm now able to give the url_user_id the right value, but my function get_username() can't access that value. My get_session_user_id function now looks like this:

// get SESSION user_id
        function get_session_user_id() {
            $.post( "http://localhost/snapll_back/account/session_user_id.php",
            function(info) {        
                if(info != "Something went wrong. ERROR{1_RAI_ERROR}") {
                    session_user_id = info;
                    alert("session user id = " + session_user_id);

                    // if url_user_id is not defined by the URL give it the value of session_user_id
                    if(url_user_id == 'undefined' || url_user_id == "" || url_user_id == null) {
                        url_user_id = session_user_id;  
                        alert("url user id = " + url_user_id); 
                    }

                    // hide the follow button if this me is owned by the viewer
                    if(session_user_id == url_user_id) {
                        $("#follow_button").hide();
                    }
                }
                else {
                    $('#warning').html(info).fadeIn(200);
                    setTimeout(function () {
                       window.location.href = "index.html";
                    }, 2000);
                }
            });
            return false;   
        }

It alerts url_user_id with the correct value when no id is specified in the URL, but the get_userame function still says 'undefined' when I alert it in that function. Why can't the get_username function get the most recent value of url_user_id?

Upvotes: 0

Views: 68

Answers (1)

iabw
iabw

Reputation: 1108

It looks like you're calling get_username immediately, before get_session_user_id has had a chance to return.

Try doing this:

// get URL parameter (user_id)
    function GetURLParameter(sParam) {
        var sPageURL = window.location.search.substring(1);
        var sURLVariables = sPageURL.split('&');
        for (var i = 0; i < sURLVariables.length; i++) 
        {
            var sParameterName = sURLVariables[i].split('=');
            if (sParameterName[0] == sParam) 
            {
                return sParameterName[1];
            }
        }
    }

    // get URL parameter (user_id) function call
    url_user_id = GetURLParameter('id');

    // get SESSION user_id
    function get_session_user_id() {
        $.post( "http://localhost/snapll_back/account/session_user_id.php",
        function(info) {        
            if(info != "Something went wrong. ERROR{1_RAI_ERROR}") {
                session_user_id = info;
                //alert("session user id = " + session_user_id);

                // if url_user_id is not defined by the URL give it the value of session_user_id
                if(url_user_id == 'undefined' || url_user_id == "" || url_user_id == null) {
                    url_user_id = session_user_id;  
                    //alert("url user id = " + url_user_id); 
                }

                // hide the follow button if this me is owned by the viewer
                if(session_user_id == url_user_id) {
                    $("#follow_button").hide();
                }
            }
            else {
                $('#warning').html(info).fadeIn(200);
                setTimeout(function () {
                   window.location.href = "index.html";
                }, 2000);
            }

            // get username function call
            get_username();

        });
        return false;   
    }

    get_session_user_id();  

    // get username function
    function get_username() {
        //alert(url_user_id);
        $.post( "http://localhost/snapll_back/account/username.php?id="+url_user_id,
        function(info) {        
            if(info != "Something went wrong. ERROR{1_RAI_ERROR}") {
                $("#main_header_username").html(info);
            }
            else {
                $('#warning').html(info).fadeIn(200);
            }
        });
        return false;      
    }

    /*
    * function calls
    */
    // check session function call
    check_session();

We've moved the call to get_username inside the success callback to your POST, but otherwise the code is the same.

Upvotes: 1

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