ajax - How to reload datatable by using new url and some parameters without reinitialize it

Question

I know I can make ajax request on datatable using ajax.url like this :

var table = $('#example').DataTable( {
    ajax: "/mylink"
} );

...

table.ajax.url( 'newData.json' ).load();

But how can I pass data as parameters to url using the same syntax? I try table.ajax.url( 'mylink' ).data(myData).load(); . Obsviouly it is not solution.

I do not want to destroy and reinitialize the datatable in order to use :

...
"ajax" : {
        "url" : "mylink",
        "data" : myData
 }
 ...

What do I do? What is the syntax using existing initialized table (here js var table)? thanks

Answer 1

In your DataTables ajax section, instead of using the object form of the data option, you can use the function form. This allows you to dynamically pass in your request data for each new ajax call.

So, instead of this:

"data" : myData

It would be this:

"data": function () {
  return myData;
}

And, as you already note, you can use the ajax.url() call to specify the new URL:

table.ajax.url( 'newData.json' ).load();

---

Warning: This assumes you are not using server-side processing, as this will overwrite the server-side request data which is auto-generated by DataTables. If you are using server-side processing, then you have to merge your custom data into the pre-existing request data.

The documentation shows an example for that, using jQuery extend:

"data": function ( d ) {
  return $.extend( {}, d, {
    "extra_search": $('#extra').val()
  } );
}

You don't need to use $.extend. You just need to be careful that you do not overwrite the request data generated by Datatables.

Another way to handle this is to simply append data to the data structure represented by d in "data": function ( d ):

"data": function ( d ) {
  d.extra_search = $('#extra').val();
}

---

Update with a more detailed example

Here is a full example, which you can copy into a html file and run for yourself, if you wish. It uses data from a dummy JSON provider, just for testing.

The HTML, showing the table and a button. The button is how I tested the ability to call a new URL and pass new request parameters to that new URL:

<div style="margin: 20px;">
    <button id="button_one" type="button">Resubmit</button>
    <br><br>
    <table id="example" class="display" style="width:100%"></table>
</div>

Here is the related script containing the DataTable definition and a function which calls the new URL (with new request parameters):

<script>

$(document).ready(function() {

  // ajax for initial table creation:
  var requestUrl = "https://jsonplaceholder.typicode.com/posts";
  var requestData = { "name": "Abel", "location": "here" };

  var table = $('#example').DataTable( {
    ajax: {
      method: "GET",
      url: requestUrl,
      "data": function ( ) {
        return requestData;
      },
      dataSrc: "",  
    },
    "columns": [
      { "title": "User ID", "data": "userId" },
      { "title": "ID", "data": "id" },
      { "title": "Title", "data": "title" }
    ]
            
  } );
  
  $("#button_one").click(function() {
    // subsequent ajax call, with button click:
    requestUrl = "https://jsonplaceholder.typicode.com/todos";
    requestData = { "name": "Charlie", "location": "there" };
    table.ajax.url( requestUrl ).load();
  });
  
} );

</script>

The key points in this example are:

1. There are 2 different URLs. The first one is used when DataTables is created. The second one is used when the button is clicked.

2. There are 2 different sets of request data, for the two URLs.

Using this approach, you can repeatedly call table.ajax.url( requestUrl ).load() with different URLs and different sets of request data, without needing to destroy the DataTable.

---

Handling Form Data

Here is a simple HTML form:

<form id="filter-form">
    City:<input type="text" id="city" name="city">
    Country:<input type="text" id="country" name="country">
    <input type="submit" value="Submit">
</form> 

For testing, I have the following JavaScript which captures the contents of the form into an array:

var form_data = [];

$( "#filter-form" ).submit(function( event ) {
  event.preventDefault();
  form_data = $( this ).serializeArray();
  table.ajax.url( url ).load();
});

The end result is data like this in the form_data variable:

[
  {
    "name": "city",
    "value": "Berlin"
  },
  {
    "name": "country",
    "value": "Germany"
  }
]

Now I can merge that data into the automatically created server-side request data. This is where I can choose to use the $.extend() function I mentioned above:

  $('#example').DataTable( {
    serverSide: true,
    ajax: { 
      method: "POST",
      url: url, // from a variable
      data: function( d ) {
        return $.extend( {}, d, { "my_extra_data": form_data } );
      }
    },
    ... //whatever else is in your DataTable definition...
  });

This function results in request data like the following:

{
    "draw": "2",
    "columns[0][data]": "id",
    "columns[0][name]": "",
      ...
    "start": "0",
    "length": "10",
    "search[value]": "",
    "search[regex]": "false",
    "my_extra_data[0][name]": "city",
    "my_extra_data[0][value]": "Berlin",
    "my_extra_data[1][name]": "country",
    "my_extra_data[1][value]": "Germany"
}

You can see your my_extra_data values are included along with the server-side auto-generated request data. And all of this gets sent to the server as part of your request.

If you are using POST then it's in the request body.

If you are using GET, then it's the same data - but added to the URL as a query string.

In both cases, it's converted to the standard string representation used by form data.

It's then up to the server-side code to access this data in the usual way.

NOTE: You may have expected your URL-encoded form data to be provided as this:

...&city=Berlin&country=Germany

But instead it is provided as arrays of name/value pairs:

&my_extra_data%5B0%5D%5Bvalue%5D=Berlin&my_extra_data%5B1%5D%5Bname%5D=country&my_extra_data%5B1%5D%5Bvalue%5D=Germany

So, there is extra server-side work needed to parse this data.

If you want to convert your form data directly into a JavaScript object like this:

{ "city": "Berlin", "country", "Germany" }

then take a look at the answers to this question:

Convert form data to JavaScript object with jQuery