searching/filtering using custom predicate function

mewalig

Hi,

I would like to be able to "search" my datatable (that is, filter the displayed rows) by a custom predicate function that I define, which would serve as an additional "and" condition that must be met for a row to be displayed. Basically, I want to do:

$(t).DataTable({
  customSearch: function(dataIndex) {
    return dataIndex % 2 == 0; // whatever custom filter logic I want here
  }
});

I was able to find plenty of documentation on searching using strings, regex's etc, but I did not see any support for doing this, so I made a 5-line change to datatables.js to support this feature.

My questions are:
1. Is there already support for this?
2. If there is not already support for this, how can I turn my 5-line change into a plug-in (or get it merged into the base code)?

FWIW the changes are as follows. Take them please...

diff --git a/datatables.js.orig b/datatables.js
index 80ec166..2ccfc32 100644
--- a/datatables.js.orig
+++ b/datatables.js
@@ -1024,6 +1024,7 @@
                                "sAjaxDataProp",
                                "iStateDuration",
                                "sDom",
+                          "customSearch", // added
                                "bSortCellsTop",
                                "iTabIndex",
                                "fnStateLoadCallback",
@@ -4315,6 +4316,13 @@

                /* Tell the draw function we have been filtering */
                oSettings.bFiltered = true;
+
+
+          if(oSettings.customSearch) /// added
+            oSettings.aiDisplay = oSettings.aiDisplay.filter((ind) => { /// added
+              return oSettings.customSearch.call(oSettings.oInstance, ind); /// added
+            }); /// added
+
                _fnCallbackFire( oSettings, null, 'search', [oSettings] );
        }

kthorngren

Sounds like you want to create a search plugin:
https://datatables.net/manual/plug-ins/search

Kevin

mewalig

Yes, that's perfect. Thank you!

mewalig

Just one follow-up to generalize the search plug-in approach: if I want to use a different custom search function (or no function) for each datatable, where the table-specific function is determined at the time of the DataTable creation/initialization (e.g. because it uses local variables), what is the easiest approach? I suppose I could do:

plug-in:

$.fn.dataTable.ext.search.push(
    function( settings, searchData, index, rowData, counter ) {
      if(!settings.nTable._myCustomFunc)
        return true;
      return settings.nTable._myCustomFunc(settings, searchData, index, rowData, counter);
    }
);

and then when the datatable is created, do:

let t = document.createElement('table');
let my_local_variable = 15;
t._myCustomFunc = function(_settings, _searchData, index) {
  return (my_local_variable == index);
};
let $dt = $(t).DataTable(datatable_options);

but is there a better way? In particular, is there a recommended place to store arbitrary, user-managed data (including a function), which would fill the role that I am using t._myCustomFunc to fill above?