The built-in filter search types include:

Priority	Type	Designator	Function
1	regex	/./mig	$.tablesorter.filter.types.regex
2	operators	< <= >= >	$.tablesorter.filter.types.operators
3	not	! or !=	$.tablesorter.filter.types.notMatch
4	exact	" or =	$.tablesorter.filter.types.exact
5	and	&&  or  and	$.tablesorter.filter.types.and
6	range	-  or  to	$.tablesorter.filter.types.range
7	wild	* or ?	$.tablesorter.filter.types.wild
7	or	| or  or	$.tablesorter.filter.types.wild (built-into wild)
8	fuzzy	~	$.tablesorter.filter.types.fuzzy

• The first step is to decide what you want your filter to do.
• Should it look for a symbol at the beginning, middle or end of the filter?
• Does the designator need spaces around it (e.g. " and " or " or ") to prevent problems? You wouldn't be able to find the country of "Andorra" if the "and" or "or" designators didn't require spaces.
• Make sure to name your filter so that it doesn't interfere with already existing ones, unless your filter is meant to replace an existing one. See the "Built-in Filters" section for a full list of filter function names.
• Changed in v2.17.8, only two parameters are passed to the filter type function:

  $.tablesorter.filter.types.myNewFilter = function( config, data ) { /* ... */ }

  • config - tablesorter config containing all variables (table.config)
  • data - filter data containing all filter variables. All variables are listed below.
  
  
• Within your filter, first test for your designator symbol.
  • If it exists within the filter, then do your comparison and return a boolean of true or false.
  • The following arguments are passed to the filter function within the data parameter (changed in v2.17.8):
    • data.filter - The exact text from the filter input (e.g. ^h).
    • data.iFilter - The text from the filter in all lower case for case insensitive searches, if table.config.widgetOptions.filter_ignoreCase is true.
    • data.exact - The exact (or parsed) text from the current table cell, or the entire row if data.anyMatch is true; the parsed text is passed when the column has a "filter-parsed" class name set.
    • data.iExact - The exact (or parsed) text in all lower case for case insensitive searches, if table.config.widgetOptions.filter_ignoreCase is true.
      
      
    • data.index - The current column index (zero-based) being filtered. When performing an "any match", this index is equal to config.columns which is the last column of the table plus one.
    • data.cache - The parsed text from the current table cell, or the entire row if data.anyMatch is true. This value will be in all lower case if config.ignoreCase is true.
      
      
    • data.anyMatch - This is a boolean value indicating when the data.exact and data.iExact parameters contain data from the entire row instead of one cell. This value will always be false if the table does not include an associated any match filter.
      
      
    • data.rowArray - An array of the exact text from each table cell.
    • data.cacheArray - An array of parsed text from each table cell.
    • data.childRowText - contains all text from any associated child rows.
    • data.parsed - An array of boolean flags that indicate if the column data should obtained from parsed values, or not; obtained from filter_useParsedData setting or filter-parsed classes on the header cells.
      Note Be aware that the values in this array will all be in lower case if the table.config.ignoreCase option is true.
    
    
  • If your designator doesn't exist, you *must* return null to allow comparisons with other filter types.
  
  
• Here is a basic example with extensive comments:

  // search for a match from the beginning of a string
  // "^l" matches "lion" but not "koala"
  $.tablesorter.filter.types.start = function( config, data ) {
    // test for filter type designator. In this example, "^" must be at the beginning of the filter
    // for this test, the use of the case insensitive "iFilter" variable
    // doesn't matter since we are only looking at the symbol
    if ( /^\^/.test( data.iFilter ) ) {
      // test the table content (exact or parsed) against the filter
      // * Don't forget to remove the designator first ( the substring(1) part ), so "^h".substring(1) becomes "h"
      // * In this case, we do care about using "iFilter" since we're comparing it with "iExact"
      // * We use "indexOf" so that we know the match starts from the beginning of the string.
      // * Your function should return a boolean indicating a match, or not.
      return data.iExact.indexOf( data.iFilter.substring(1) ) === 0;
    }
    // ALWAYS return null if your custom filter type doesn't match
    return null;
  };

• If one of the built-in search types is interfering or bothersome to your users, then you can remove it using the following command (using fuzzy search as an example):

  $(function(){
  
    // Remove fuzzy search
    delete $.tablesorter.filter.types.fuzzy;
  
    $('table').tablesorter({
      theme: 'blue',
      widgets: ['filter']
    });
  
  });

• The full list of built-in filter type functions can be found in the "Built-in Filters" section.

You can change the language of the searches used within the filter widget. This only applies to the "and", "or" and "to" (range) searches. For example, to change the localization to French, do the following:

// add French support
$.extend($.tablesorter.language, {
  to  : 'à',
  or  : 'ou',
  and : 'et'
});

This results in searches that can be performed as follows:

• "and" search: Pierre et Franc or Pierre && Franc.
• "or" search: Marie ou Claudette or Marie|Claudette
• "to" search: 10 à 20 or 10 - 20

Note the symbolic searches never changed ( && , | and  - )
Important Even though the language settings don't include spaces, the user is still required to enter spaces in the filter to perform these searches, e.g. 1 à 10 (shows rows with numbers between 1 and 10).

---

If you want to support multiple languages, separate the language variables with a vertical bar (|, Shift + \):

// add French & Spanish support
$.extend($.tablesorter.language, {
  to  : 'à|a',
  or  : 'ou|o',
  and : 'et|y'
});