ajax

Description

Gantt ajax module

ajax: any

Example

// assuming that the response is the following
{status: "ok", data: "value", data2: "value2"}


var xhr = gantt.ajax;

// HTTP GET
xhr.get("server.php").then(function(response) {
    var res = JSON.parse(response.responseText); 
    if (res && res.status == "ok") {
        // response is ok
    }
});

// HTTP POST
xhr.post({
    url:"server.php", 
    data: {
       paramName: "paramValue"
    }
}).then(function(response){
    var res = JSON.parse(response.responseText); 
    if (res && res.status == "ok") {
        // response is ok
    }
});

API Reference

All methods can take as parameters either:

1. RequestConfig - an object with request config options, which looks as follows:

{
  url: string,
  method: "PUT|GET|POST|DELETE",
  data: string | object,
  async: true|false
  callback: function,
  headers: object
}

where:

• url - the URL to the server side
• method - optional, the method used for sending request, "GET" by default
• data - optional, the data sent to the server side by the POST-request. The POST and PUT methods accept both a string and an object with data
• async - optional, the mode of sending data to a server, true by default
• callback - optional, a function to call after the response is loaded
• headers - optional, a set of headers, defined as "key":"value" pairs that should be sent with a request

or:

2. Three parameters (except for the query() method which can take only the RequestConfig object):

• url - the URL to the server side
• data - optional, the data sent to the server side by the POST-request
• callback - optional, a function to call after the response is loaded

The list of the ajax module API is given below:

Callback options

All methods allow both callbacks or promises for response handling.

An ajax promise returns a completed XmlHttpRequest:

gantt.ajax.post({ 
    url:"some.php",
    data: {
       paramName: "paramValue"
    }
}).then(function(response){
    alert(response.responseText);
});

For historical reasons, the callback option receives value in a slightly different format:

gantt.ajax.post({ 
    url:"some.php",
    data: {
       paramName: "paramValue"
    },
    callback: function(result){
       var response = result.xmlDoc;
       
       alert(response.responseText);
    }
});

query

the common method of sending requests. Allows sending any type of request (you need just to specify the desired request in the parameters)

gantt.ajax.query({ 
    url:"some.php",
    method:"POST",
    data: {
       paramName: "paramValue"
    }
}).then(function(response){
    alert(response.responseText);
});

get

sends a GET request

gantt.ajax.get("some.php", function(){
    // your code here
});
// or
gantt.ajax.get({
    url: "https://…",
    callback: function() {…},
    headers: { "Content-Type": "application/json" }
});

put

sends a PUT request

gantt.ajax.put("server.php", "keep_alive=1&version=std", function(){
    // your code here
});
// or
gantt.ajax.put({
   url: "https://…",
   callback: function() {…},
   headers: { "Content-Type": "application/json" }
   data: {}
});

del

sends a DELETE request

gantt.ajax.del("server.php", function(){
    // your code here
});
// or
gantt.ajax.del({
   url: "https://…",
   callback: function() {…},
   headers: { "Content-Type": "application/json" }
});

post

sends a POST request

gantt.ajax.post("server.php", "keep_alive=1&version=std", function(){
    // your code here
});
// or
gantt.ajax.post({
      url: "https://…",
      callback: function() {…},
      headers: { "Content-Type": "application/json" }
      data: {}
});

Sending data with POST/PUT methods

You can pass an object with data instead of string into the post and put methods. In case an object is passes, the ajax module serializes it by itself. A simple object will be serialized as form data (&param=value), nested structures will be serialized with the help of JSON.stringify().

For example, the following object:

{
    id: 1,
    text: "My Task",
    users: [1,2,3]
}

will be converted into a string that looks like id=1&text=My%20Task&users=%5B1%2C2%2C3%5D.

Promises

dhtmlxGantt supports usage of promises (including IE8+). For work with promises Gantt uses the Bluebird promise library. To create a promise, you need to use the following constructor:

var promise = new gantt.Promise(function(resolve, reject) {...});

Promise is declared inside Gantt, not globally for the application.

The AJAX module returns a promise, which allows using the promise interface instead of the callback. Thus instead of using

gantt.ajax.post(url, params, callback);

For example, when sending a POST request, you can use the following record:

gantt.ajax.post(url, params).then(function(){…});

It is possible to use callbacks and promises at the same time.

The example below shows how you can send several requests to the server at once, and reload data after that:

gantt.Promise.all([
      gantt.ajax.post({url: "api/task", data: task1}),
      gantt.ajax.post({url: "api/task", data: task2}),
      gantt.ajax.post({url: "api/task", data: task3})
]).then(function(){
   gantt.clearAll();
   gantt.load("/api");
});

Change log

• added in version 4.0