Search Pattern Cookbook

The Search function in TWiki is very powerful. Especially searches using a RegularExpression play an important part of tapping TWiki's full potential. Unfortunately RegularExpressions can be incredibly obscure to the uninitiated.

Most people not familiar (enough) with Regular Expressions mostly cut and paste (and maybe tweak) from existing examples. This page intends to collect lots of examples together.

Pattern 1: Extract values from a table

Problem definition

| *Name* | *Type* | *Tooltip message* |
| option1 | option | |
| option2 | option | |
| option3 | option | |

How to extract the 'name' values, i.e. 'option1', 'option2' and 'option3' and put them in a HTML form select input?

Solution

<form>
<select>

which is, in effect:

Pattern 2: List generated from form classification

Problem

1. create a search to display all topics where one form field is set to a certain value
2. create a search to filter the list above based on the values of a second form field

Test case

• TopicClassification = One, Two or Three
• TopicStatus = Test or Final

We will:

1. List all topics where the TopicClassification field is set to 'Two'
2. Enable the user to filter this list based on the values of TopicStatus

Solution

%SEARCH{"[T]opicClassification.*value\=.*Two;[T]opicStatus.*value\=.*%URLPARAM{type}%"

The filtering select dialogue is created as in Pattern 1:

%STARTSIDEBAR%
*Filter:* %BR%
<form name="selectType" action="%SCRIPTURLPATH{"view"}%/%WEB%/" >
<select name="type" size="1" onchange="document.location=this.value;"> 

This will create similar functionality as TWiki:Plugins.TopicClassificationAddOn

Pattern 3: Creating lists of TWiki usernames

Problem

How to populate a list box with all usernames of registered TWiki users

Solution 1: Appropriate for Sep 2004 TWiki (Cairo)

<form name="testing" action="%SCRIPTURLPATH{"view"}%/%MAINWEB%" method="get">
<select name="topic">
<option>Select user...</option>
%SEARCH{ "Name:;Email:;Country:" web="%MAINWEB%" type="regex" nosearch="on" nototal="on" format="<option>$topic</option>" }%
</select>
<input type="submit" value="Go" />
</form>

Which expands to this: (here limited to all Z* users because TWiki.org has so many)

This searches all topics in the Main web that contain "Name", "Email" and "Country" bullets. Alternatively, do a FormattedSearch with multiple="on" on the Main.TWikiUsers topic.

Solution 2: As Solution 1, but with possibility for multi-selecting usernames

<select name="topic" size="2" MULTIPLE>

Please note that the Search pattern is unchanged compared to Solution 1. The change is in the HTML form element.

The abovementioned modification is, in effect:

Solution 3: Appropriate for TWiki 4 (Dakar)

<form name="testing" action="%SCRIPTURLPATH{"view"}%/%MAINWEB%" method="get">
<select name="topic">
<option>Select user...</option>

In the above example:

• META:FORM.*[U]serForm will search for all topics with a UserForm attached - change this if you have a different form where userdata is stored. Please note that this search does not actually extract anything from the form - it just uses it to identify the appropriate pages
• excludetopic="Test*, TWiki*" allows to skip all topics starting with Test and TWiki, such as TestUser or TWikiAdmin. Use this if you have any special users who you do not want appearing in this list

Pattern 4: Extract the parent of a given topic

Problem

How to get to the parent of the current topic to display on the page?

Problem

Solution

Thanks to TWiki:Main.PeterThoeny for these solutions.

<form>
<select name="topic">
<option value="%TOPIC%">Select...</option>
%SEARCH{ "%HOMETOPIC%" scope="topic" web="all" topic="%HOMETOPIC%" format="<option value=\"$web.$topic\">$web</option>" separator=" " }%
</select>
<input type="submit"  value="Go" />
</form>

Test case

Public webs of TWiki.

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

<--/patternSearchResultCount-->

For private webs, or any other webs you wish to exclude from the display, use "on" for the Exclude web from a web="all" search setting in the relevant web's WebPreferences topic.

Alternative solution

This result can also be accomplished with the %WEBLIST% variable.

Problem

Solution

Search for the Name: entry.

Test case

To create a test case, we will put a name entry here:

• Name: John Doe

Search result:

Problem

• why is this searching the metadata, shouldn't it just search the text?
• what is the meaning of the td..td in the search expression?

Solution

An example meta data form field is:

%META:FIELD{name="OperatingSystem" title="OperatingSystem" value="OsWin"}%

• Using square brackets is a trick to avoid a hit on the topic doing the search.
• The .* indicate that there can be any number of any character between OperatingSystem and value in the (whole) file

Now the original file format of the category table (the predecessor of the TWiki forms) looks like this:

<td valign="top" align="right"> OperatingSystem:  </td><td>  OsWin </td>

The td..td matches td<>td; a simple search on "[O]peratingSystem.*[O]sWin" could find a hit in the topic text by coincidence.

A simple %SEARCH{ "[O]peratingSystem.*value\=.*[O]sWin" ...}% search is sufficient if you do not have topics in the old format.

Problem

Solution