使用$ .post从javascript页面验证目录以调用webservice PHP函数

Question

I am trying without success to use the $.post function to test (via a webservice that calls a PHP function "is_dir") if a folder already exists on a server and then I want it to return a string or boolean value back to my javascript page before I proceed to dynamically write the new files that will be placed there. The file path of the folder to be tested is "built" using jQuery which captures form data. I need to define (in a variable) if the directory exists and then be able to access that variable from outside of the $.post function (not from within, using success callback). This is so I can proceed in javascript as follows:

if {directory exists} then capture more form data (via jQuery) and $.post to webservice that calls PHP to update database

Outside of the $.post function, the value of my return variable is undefined.

I think I may be over-complicating this. Any suggestions? Thank you, in advance.

Answer 1

Please see my comment to @Steve above:

   <script type='text/javascript'>

    //function gathers form data, validates constructed file path and then writes to DB
    function post_FormData() {

        var week_number          = $("#form_week_number").val();
        var program              = $("#form_program").val();
        var course               = $.trim($("#form_course_number").val());
        var form_content_type    = $("input:radio[name=content_type]:checked").val();
        var content_type         = "";      
        var activity_title_Val   = $.trim($("#form_activity_name").val());
        var activity_title_Split = activity_title_Val.split(" ");
        var activity_title_Clean = new Array();

        //this for-loop constructs a valid directory folder name from form data
        for(var i=0, l=activity_title_Split.length; i<l; i++) {

            activity_title_Split[i] = activity_title_Split[i].replace(/[^a-z0-9\s]/gi,"");
            activity_title_Clean[i] = activity_title_Split[i];
            activity_title_Split[i] = activity_title_Split[i].replace(/\b[a-z]/g, function(letter){return letter.toUpperCase();});
        }

        var activity_title = activity_title_Split.join("");

        var file_path  = "";

        file_path     += "/CourseFiles/" + program + "/" + program + course + "/" + content_type + "/Week" + week_number + "/activity-" + activity_title;

        var message    = "<div id=\"confirmation_container_contents\"><p><b>Confirm Content Repository file path: </b><br></p>";

        //begin web service call to PHP function
        $.post('webservices/create_PA_webservices.php', {web_service: "go_check_if_exists", data_file_path: file_path}, function(data){

            var exists = data.does_exist; //json_encoded RESPONSE FROM ASYNC REQUEST

            if(exists == "Y") {

                message   += file_path;
                message   += "<br><br><br><center><b>An activity folder with this name already exists.</b></center>";
                message   += "<br><br><center>Please edit the activity title and resubmit.</center>";
                message   += "<br><br><br><center><input type=\"image\" src=\"pa_images/editButton.jpg\" id=\"editButton\" value=\"edit\"></center></div>";

                $("#confirmation_container").empty();
                $("#confirmation_container").append(message);

            }
            else if(exists == "N") {

                message   += file_path;
                message   += "<br><br><center><input type=\"image\" src=\"pa_images/editButton.jpg\" id=\"editButton\" value=\"edit\">";
                message   += "&nbsp\;&nbsp\;&nbsp\;<input type=\"image\" src=\"pa_images/confirmButton.jpg\"  id=\"confirmButton\" value=\"confirm\"></center></div>";

                $("#confirmation_container").empty();
                $("#confirmation_container").append(message);

            }

            $(function(){//edit proposed file path

                $("#editButton").click(function() {

                    $("#confirmation_container").empty();

                });//end function edit path button

            });//end anonymous function


            $(function(){//confirm proposed file path and write to DB

                $("#confirmButton").click(function() {

                    go_post_FormData(activity_title_Val, file_path, week_number,  program, course, content_type);
                    $("#create_practice_activity").hide();
                    $("#build_practice_activity").show();
                    $("#activity_is_new").val("N");

                });//end function confirm path button

            });//end anonymous function


        }, "json").fail(function() {alert("The go_check_if_exists webservice call has failed");}); //end web service call  

    }//end function post_FormData declaration

    </script>