How to pass a value with dataSource.read()?

[Tayger]

Hi

I would like to send a value (userid) with the read command of dataSource. I've done several tests but I can't catch the posted value in PHP.

Working ( $userid = $_POST["userid"] = 1234 on server side):

            $.ajax({
                type: 'POST',
                url: 'readparameter.php',
                data: {userid: "1234"},
                async: true,
                dataType: 'json',
                success: function(result) {      
                   console.log (result);
                }
            });

Not working ( $userid = $_POST["userid"] = NULL on server side):

var mySource = new kendo.data.DataSource({
            dataType: 'json',
            transport: {
                read: function (options) {
                    $.ajax({
                        type: "POST",
                        dataType: 'json',
                        async: true,
                        data: {userid: "1234"},
                        url: "readparameter.php",
                        success: function (result) {
                            console.log (result);
                        }
                    });
                }
            }
        });

My assumption is that the posted userid never reaches the server using dataSource. I'm trying since a lot of time and tried several ways like also Json.stringify etc. What am I doing wrong or is it just not possible to pass a value with dataSource?

[Tayger]

Ok, the solution is to add the "type" parameter. Example:

var mySource = new kendo.data.DataSource({

    transport: {
        read: {
            url: "../php/readpage.php",
            dataType: "json", 
            type: "POST",
            data:  {
                skip: 0,
                take: 2
            }
        }
    }
});

[Ianko]

Hi Tayger,

There is a dedicated property option you can use for each of the CRUD operations called data: https://docs.telerik.com/kendo-ui/api/javascript/data/datasource/configuration/transport.read#transportreaddata. I am mystified why the ajax call that is wrapped with the read function could suffer from that brahavior. However, the proper and supported way is to use the DataSource.Transport's data property instead.

Regards,
Ianko
Progress Telerik

[Tayger]

Thanks for the answer. Of course I've tried that as well (datasource of a KendoUiDropdownlist). Didn't work either. As workaround I have created a pure $.ajax call and fill up the dropdownlist manually, works.

[Ianko]

I suggest you checking the request headers of the sent AJAX request and compare it with the successful one. Let me know what are the differences so that the data i snot passed through the data option.