Custom search function doesn't work

Custom search function doesn't work

walruswalrus Posts: 5Questions: 2Answers: 0

I'm trying to build up custom search function that implements inclusive or logic across multiple columns using multiple criteria, but I can't seem to get it work properly - search returns empty result set.
My HTML:

<!doctype html>
<html>
<head>
  <script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
  <script src="https://cdn.datatables.net/1.10.19/js/jquery.dataTables.min.js"></script>
  <script src="test2.js"></script>
  <script src="mFilter.js"></script>
  <link rel="stylesheet" type="text/css" href="test.css">
  <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/1.10.19/css/jquery.dataTables.min.css">
</head>
<body>
  <table id="mytable"></table>
  <button id="mybutton">Search for apple and vegies</button>
</body>
</html>

My jQuery:

var srcData = [
    {name:"apple", category:"fruit"},
  {name:"banana", category:"fruit"},
  {name:"cabage", category:"vegie"},
  {name:"carrot", category:"vegie"},
];

var dataTable = $('#mytable').DataTable({
    sDom: 't',
  data: srcData,
  columns: [
    {data: 'name', title: 'Name'},
    {data: 'category', title: 'Category'}
 ]
});

$.fn.DataTable.ext.search.push(function(settings, searchData, index, rowData){
    if(rowData.name == searchData[0] || rowData.category == searchData[1]) return true;
  else return false;
});

$('#mybutton').on('click', function(){
    dataTable.search(['apple','vegie']).draw();
});

and jsfiddle, just in case. Any help is greatly appreciated.

This question has an accepted answers - jump to answer

Answers

  • colincolin Posts: 15,240Questions: 1Answers: 2,599

    Hi @walrus ,

    This page here should help. To search across two columns, you need to use regular expressions. So, on that page, search for (Nash|Tokyo) in the "Global search", and check the "Treat as regex" checkbox. You'll need to do something like that in your code.

    Cheers,

    Colin

  • walruswalrus Posts: 5Questions: 2Answers: 0
    edited January 2019

    @colin Thanks for your response, However, example that you refer to implements (kind of cascaded) AND logic - you search your table for one criteria within some particular column, than you search within your result set by another criteria / another column and so on.

    Thus, back to my example, you will successfully find a row that has 'apple' in its name, but you won't be able to find any vegies in the resulting data set as they were filtered out at the first step.

    Using global regex search will not work whatsoever, since by having 'an' within your search string, you'll get all the entries, matching that, regardless of the column, like 'Accountant' in 'position' field, 'Angelica Ramos' in the 'name' field and 'San Francisco' from 'office' column. So it's basically single criteria over multiple column search. I don't even mention that regex match is more expensive than exact match.

  • colincolin Posts: 15,240Questions: 1Answers: 2,599

    Hi @walrus ,

    I don't quite follow, since I believe this here is doing what you want, and is following that example that I linked to.

    Cheers,

    Colin

  • kthorngrenkthorngren Posts: 21,309Questions: 26Answers: 4,947
    edited January 2019 Answer ✓

    There are a couple issues with your search plugin. First the search value is not passed as a parameter into the search plugins. You can store the value in a variable or it could be an input on the page. Second searchData is an array of the column data not the search term. Likely you will want to use searchData instead of rowData for the row values. This section of the search plugin describes the parameters and the differences between searchData and rowData.

    I updated your example to use a global variable to store the search array and use searchData for the row data. Instead of using search() the button event simply uses draw() to start the search process.

    http://jsfiddle.net/tn1Ljcfb/1/

    In your case the search plugin isn't actually running as the global search of dataTable.search(['apple','vegie']).draw(); is actually clearing all the rows before the plugin would run. You are pushing the plugin on the end of the search array so it is executed last.

    Kevin

  • walruswalrus Posts: 5Questions: 2Answers: 0

    @colin There're two problems with your regex approach:

    First, it works for that particular case with two column data set, but when you'll need to filter across bigger number of columns you'll either be struggling to make up appropriate regex (to match value in n-th column only) or you will not get it to work properly where you have same data value in different columns and different rows.

    Second, regex matching multiple criteria across multiple columns will impose huge unnecessary load onto the browser, where you need to do strict 'x == y' matching with external search functions designed exactly for that purpose.

    However, thank you for your effort.

  • walruswalrus Posts: 5Questions: 2Answers: 0

    @kthorngren Thanks a lot for your explanation. Now I've got the way it should work.

  • colincolin Posts: 15,240Questions: 1Answers: 2,599

    I've got to be honest, I didn't even spot there was a search plugin! Glad all working, good stuff, Kevin.

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