smd_fuzzy_find

Ever wanted TXP’s search facility to be a little more, well, inaccurate? Help people with fat fingers to find what they were actually looking for with this tool that can find mis-spelled or like-sounding words from search results.

Results are ordered by approximate relevancy and it’s automatically context-sensitive because the pool of words it compares against are from your site. On a zoo website, someone typing in “lino” won’t get articles about flooring but more likely articles about lions, which is what they really wanted. We hope.

Features

• Search for similarly spelled, or similar sounding words (may be switched on/off)
• Limit the search to article status, section or category to speed up proceedings
• Tweak sensitivity to give better results (more specific, less likely to find a match) or general results (less specific, may match stuff you don’t expect)
• Can offer links to exact search terms if you wish (a bit like Google’s “Did you mean …”)
• Display matching articles using a form/container. Default is the built-in search_results form
• Unless overridden using the match_with attribute, the Title and Body will be searched. Alternatively, if you have set the search locations using wet_haystack then those places will be searched instead

Author

Stef Dawson, with notable mention to Jarno Elonen for the Fuzzy Find algorithm which — to this day — remains mere voodoo to me.

Installation / Uninstallation

Requires Textpattern 4.0.7 and smd_lib v0.33 must be installed and activated.

Download the plugin from either textpattern.org, or the software page, paste the code into the TXP Admin -> Plugins pane, install and enable the plugin. Visit the forum thread for more info or to report on the success or otherwise of the plugin.

To uninstall, simply delete from the Admin -> Plugins page.

Usage

The plugin is not a replacement for the built-in TXP search; it should be used to augment it, like this:

<txp:if_search>
  <dl class="results">
    <txp:chh_if_data>
      <txp:article limit="8" searchform="excerpts" />
    <txp:else />
      <txp:smd_fuzzy_find form="excerpts" />
    </txp:chh_if_data>
  </dl>
</txp:if_search>

Exact matches will be processed as normal but mismatches will be handled by smd_fuzzy_find. If you try to use smd_fuzzy_find on its own, you will likely receive a warning about a missing <txp:article /> tag.

Attributes

Tips and tricks

• If you can, limit the search criteria using status, section and category to improve performance
• Tweak the refine options to see if you get better or worse results for your content / language
• Most of the default values are optimal for good results, but for scientific or specialist sites you may wish to increase the tolerance and min_word_length to avoid false positives
• For offering an advanced search facility, write an HTML form that allows people to customise the search criteria (e.g. check boxes for metaphone / soundex / case_sensitive ; text boxes for tolerance / min_word_length / limit ; select lists of categories to search ; etc). Then use a series of smd_if statements inside your <txp:if_search /> to check for the existence of each URL variable, check they have acceptable values and then plug them into the smd_fuzzy_find tag using replacements such as tolerance="{smd_if_tolerance}"

Known issues

• Slow with large article sets
• Searching for a word with an apostrophe in it may cause odd character encoding or incomplete results
• Searching for multiple (space-separated) words can lead to odd results
• Sometimes it makes you laugh and picks something that seems totally unrelated

Credits

This plugin wouldn’t have existed without the original Fuzzy Find algorithm by Jarno Elonen, as noted above. All kudos goes in that direction. Also, extended thanks to the beta testers, especially Els Lepelaars for feedback and unending patience during development.