Simplifying jQuery Ajax calls in JavaScript

Luis PérezSoftware Architect in .Net
Software Architect in .Net C#, VB & ASP. Lover of Star Wars, MCU and Rock music. My greatest achievement in life: my 2 daughters.
In my daily work (mainly using, I need to write a lot of JavaScript code. One of the most repetitive tasks I do are the jQuery Ajax calls. You know:

                          type: "POST",
                          url: "MyPage.aspx/MyWebMethod",
                          data: "{parameter:value,parameter:value}",
                          contentType: "application/json; charset=utf-8",
                          dataType: "json",
                          success: function(msg) {
                              //function called successfull
                          error: function(msg) {
                              //some error happened

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I don't know if for you it's the same, but for me is soooo tedious to write the calls with this syntax. Moreover, previously it's necessary to build the string with the parameters to pass to the WebMethod, following the known rules: strings must be passed in quotes, numbers do not, etc.

So I decided to create a small but useful JavaScript class to help me with this particular issue, and now that I've done the jQuery Ajax calls are much friendly to me.

In the class constructor I pass the page name, the method name, and the success and error functions. Later, I do as many calls to the addParam method as I need. And finally I call the run method to do the Ajax call. The success and error functions must be written separately.

The parameters are treated according to their type. If the parameter is a string, I use quotes; if it's a number, I do not. A special case are date parameters. In this case, I use the getTime() function of the JavaScript date object, which gives me the number of milliseconds in the date since January 1, 1970. Later, I translate that value to UTC time so I get a final milliseconds number that I can pass to my (or C#) code as an Int64 value that I can use to rebuild the date value in .Net.

This is the complete listing of my jAjax class (with the date helper function at the end):

function jAjax(pageName, methodName, successFunc, errorFunc) {
                          //stores the page name
                          this.pageName = pageName;
                          //stores the method name
                          this.methodName = methodName;
                          //stores the success function
                          this.successFunc = successFunc;
                          //stores the error function
                          this.errorFunc = errorFunc;
                          //initializes the parameter names array
                          this.paramNames = new Array();
                          //initializes the parameter values array
                          this.paramValues = new Array();
                          //method for add a new parameter (simply pushes to the names and values arrays)
                          this.addParam = function(name, value) {
                          //method to run the jQuery ajax request
                 = function() {
                          //initializes the parameter data string
                              var dataStr = '{';
                              //iterate thru the parameters arrays to compose the parameter data string
                              for (var k = 0; k < this.paramNames.length; k++) {
                                  //append the parameter name
                                  dataStr += this.paramNames[k] + ':';
                                  if (typeof this.paramValues[k] == 'string') {
                                      //string parameter, append between quotes
                                      dataStr += '"' + this.paramValues[k] + '",';
                                  } else if (typeof this.paramValues[k] == 'number') {
                                      //number parameter, append "as-is" calling toString()
                                      dataStr += this.paramValues[k].toString() + ',';
                                  } else if (typeof this.paramValues[k] == 'object') {
                                      if (this.paramValues[k].getTime != undefined) {
                                          //date value
                                          //call to my getUtcTime function to get the number of
                                          //milliseconds (since january 1, 1970) in UTC format
                                          //and append as a number
                                          dataStr += getUtcTime(this.paramValues[k]).toString() + ',';
                                      } else {
                                          //object value
                                          //because I don't know what's this, append the toString()
                                          dataStr += '"' + this.paramValues[k].toString() + '",';
                              //if some parameter added, remove the trailing ","
                              if (dataStr.length > 1) dataStr = dataStr.substr(0, dataStr.length - 1);
                              //close the parameter data string
                              dataStr += '}';
                              //do the jQuery ajax call, using the parameter data string
                              //and the success and error functions
                                  type: "POST",
                                  url: this.pageName + "/" + this.methodName,
                                  data: dataStr,
                                  contentType: "application/json; charset=utf-8",
                                  dataType: "json",
                                  success: function(msg) {
                                  error: function(msg) {
                      function getUtcTime(dateValue) {
                          //get the number of milliseconds since january 1, 1970
                          var time = dateValue.getTime();
                          //get the UTC time offset in minutes. if you created your date with
                          //new Date(), maybe this contains a value. but if you compose the date
                          //by yourself (i.e. var myDate = new Date(1984,5,21,12,53,11)) this will
                          //be zero
                          var minutes = dateValue.getTimezoneOffset() * -1;
                          //get the milliseconds value
                          var ms = minutes * 60000;
                          //add to the original milliseconds value so we get the GMT exact value
                          return time + ms;

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And this is the syntax in use:

var ajaxCall = new jAjax('MyPage.aspx','MyWebMethod',successFunc,errorFunc);
                      ajaxCall.addParam('s','this is a string');
                      ajaxCall.addParam('d',new Date());
                      function successFunc(msg) {
                      function errorFunc(msg) {

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As an additional benefit, you can re-use the success and error functions for several ajax calls.

Hope that helps to you!! Feel free to use the jAjax class in your applications.
Luis PérezSoftware Architect in .Net
Software Architect in .Net C#, VB & ASP. Lover of Star Wars, MCU and Rock music. My greatest achievement in life: my 2 daughters.

Comments (1)

Michel PlungjanIT Expert
Distinguished Expert 2023

Why not use the built-in .get and .getJSON?

    tags: "cat",
    tagmode: "any",
    format: "json"
  function(data) {
    $.each(data.items, function(i,item){
      if ( i == 3 ) return false;

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