Getting lengthmenu value from datatable

Question

I have the following option as part of:

"lengthMenu": [[10, 20, 50, 100, -1], [10, 20, 50, 100, "All"]],

and I'm attempting to get the value selected for lengthMenu. However, after looking through the jquery API I cannot seem to find anything to get this value after it has been changed. Any possible solutions you guys can think of?

Answer 1

The DataTables Documentation has what you are looking for! The page.info() function will return a lot of different information about the paging of a DataTable, including the number of records shown on each page (the selected value for lengthMenu).

Here's a list of all the objects that will be returned by the page.info() call (all the things you can reference like how the above example does:

{
    "page": 1, //current page (0 based index)
    "pages": 6, //total number of pages
    "start": 10, //index of first element on page
    "end": 20, //index of last element on page
    "length": 10, //lengthMenu setting - this is what you want -
    "recordsTotal": 57, //total number of records
    "recordsDisplay": 57, //total number of records to display after filtering
    "serverSide": false //whether or not serverside processing is used
}

With all this in mind, what you actually want will look like this

var table = $('#example').DataTable(); //note that you probably already have this call
var info = table.page.info();
var lengthMenuSetting = info.length; //The value you want

All of this (in more detail and with some examples) is availiable at the link provided above.

EDIT: Actually, if all you want is the page length, you can use table.page.len() to just get the length of the page, instead of getting table.page.info().length.