TextFilter

This library provides a standard interface (TheWilkyBarKid\TextFilter\TextFilter) for text filters. The interface defines a single method, filter(), which takes a string and returns a (presumably modified) string.

That in itself isn't particularly useful, but it does open up some interesting possibilities.

It also provides some adapters, allowing you to indirectly use libraries through the interface.

Installation

1. Add TextFilter to your dependencies:

   // composer.json
   
   {
      // ...
      "require": {
          // ...
          "thewilkybarkid/text-filter": "~1.0"
      }
   }
   

2. Use Composer to download and install TextFilter:

   $ php composer.phar update thewilkybarkid/text-filter
   

Chaining filters

The TheWilkyBarKid\TextFilter\TextFilterChain class takes any number of text filters and runs through them one after another (in a user-controlled order).

This allows you to build a potentially-lengthy chain of filters, simplifying your logic when actually using them:

$filter = new TextFilterChain(array($markdownFilter, $smartyPantsFilter, $htmlPurifierFilter));

// later on
$output = $filter->filter('some markdown');

Caching filters

Normally you should persist the result of your filters alongside the plain input to avoid running it through potentially expensive filters at runtime. As this isn't always possible, the TheWilkyBarKid\TextFilter\DoctrineCacheTextFilterWrapper class wraps a text filter and caches the result in a Doctrine cache driver (file-based, Memcache, Redis etc).

$chain = new TextFilterChain(array($markdownFilter, $smartyPantsFilter, $htmlPurifierFilter));
$filter = new DoctrineCacheTextFilterWrapper($cache, $chain));