Search Pattern CookbookThe Search function is very powerful. Searches using a RegularExpression play an important part of tapping Foswiki'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.On this page:
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Pattern 1: Extract values from a tableProblem definitionSuppose there is a topic with a table defining entries in a data form. I.e. they define select menu items in a form definition. They are then formatted like:| *Name* | *Type* | *Description* | | 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 1The following search pattern can be employed:%STARTSECTION{"solution1"}% <form> <select> %SEARCH{ "^\|[^\|]*\| *option *\|" topic="%TOPIC%" type="regex" multiple="on" nonoise="on" format="<option>$pattern(^\| *(.*?) *\|.*)</option>" }% </select> </form> %ENDSECTION{"solution1"}%Click to execute Solution 2If your table has this format:| *Country* | | | | Afghanistan | | Aland Islands | | Albania | | Algeria | | American Samoa | | Andorra |You need to skip the header row. Use this search: %STARTSECTION{"solution2"}% <select> %SEARCH{ "^\|[^\*\|]*\|" topic="CountryList" type="regex" multiple="on" nonoise="on" format="<option>$pattern(^\| *(.*?) *\|.*)</option>" }% </select> %ENDSECTION{"solution2"}%Click to execute Solution 3If you want to grab the complete row for each occurrence of a string in a table, for instance the word "Marketing":| a | b | c | d | e | | Marketing | b | c | d | e| | a | b | c | d | e | | a | marketing | c | d | e | | a | b | c | d | marketing |use this query: %STARTSECTION{"solution3"}% %SEARCH{ "^\|.*?Marketing.*" type="regex" topic="%TOPIC%" multiple="on" nonoise="on" format="| $pattern(^\| *(.*?) *|.*)" }% %ENDSECTION{"solution3"}%Click to execute <--
Pattern 2: List generated from form classificationProblemImagine a form-based topic classification, i.e. every page has a form with several fields. How to:
Test caseIn practice:Image a form with two fields:
Solution%STARTSECTION{"solution4"}% %SEARCH{ "TopicClassification='%URLPARAM{"type" default="FrequentlyAskedQuestion"}%'" type="query" nonoise="on" sort="topic" format=" * [[$topic]] - <span class='foswikiGrayText'>$date, [[$wikiusername]]</span>" }% %ENDSECTION{"solution4"}%Click to execute The filtering select dialogue is created as in Pattern 1: %STARTSECTION{"solution5"}% *Filter:* <form name="selectType" action="%SCRIPTURLPATH{"view"}%/%WEB%/" > <select name="type" size="1" onchange="document.location=this.value;"> %SEARCH{ "^\|[^\|]*\| *option *\|" topic="TopicClassification" type="regex" nonoise="on" format="<option value='%BASETOPIC%?type=$pattern(^\| *(.*?) *\|.*)'> $pattern(^\| *(.*?) *\|.*)</option>" }% <option value='%BASETOPIC%'>All pages</option> </select> </form> %ENDSECTION{"solution5"}%This will create similar functionality as Foswiki:Extensions.TopicClassificationAddOn Click to execute <--
Pattern 3: Extract the parent of a given topicProblemHow to get to the parent of the current topic to display on the page?Solution 1: Using QUERYUse the QUERY macro:%STARTSECTION{"solution6"}% Parent of [[%TOPIC%]] is [[%QUERY{ "parent.name" }%]] %ENDSECTION{"solution6"}%Click to execute <--
Pattern 4: Show all Children of a given topicProblemHow to get to the list of all children of the current topic to display on the page?SolutionThe parent information is stored in the topic meta data. Do a SEARCH to find all topic parent meta data pointing to the current topic:%STARTSECTION{"solution7"}% %SEARCH{ "parent.name='%HOMETOPIC%'" type="query" nonoise="on" header="*Children:* " format="[[$topic]]" separator=", " }% %ENDSECTION{"solution7"}%Click to execute See also HierarchicalNavigation for an elaborate example. <--
Pattern 5: Search and display the home topics of public webs in a listProblemHow to find and display public webs in a drop down list box.Solution%STARTSECTION{"solution8"}% <form> <select name="topic"> <option value="%TOPIC%">Select...</option> %SEARCH{ "%HOMETOPIC%" scope="topic" web="all" topic="%HOMETOPIC%" format="<option value='$web.$topic'>$web</option>" separator=" " }% </select> <input type="submit" class="foswikiSubmit" value="Go" /> </form> %ENDSECTION{"solution8"}%Public webs can be found with the %WEBLIST% macro. Click to execute <--
Pattern 6: Create a select box with values from a bullet listProblemWe have a topic with a bullet list with category names. In another topic we want to offer these values in a select box dropdown. For example, CategoryList has:
SolutionThe following search pattern can be employed:%STARTSECTION{"solution9"}% <select name="type"> <option>Select category...</option> %SEARCH{ " *\s*.*?" topic="CategoryList" type="regex" multiple="on" casesensitive="on" nonoise="on" format="<option>$pattern(.* \*\s*([^\n]*).*)</option>" }% </select> %ENDSECTION{"solution9"}%Click to execute To render the bullet list as a comma-separated list, use the separator parameter:
%STARTSECTION{"solution10"}% %SEARCH{ " *\s*.*?" topic="CategoryList" type="regex" multiple="on" casesensitive="on" nonoise="on" separator="," format="$pattern(.* \*\s*([^\n]*).*)" }% %ENDSECTION{"solution10"}%Click to execute <--
Pattern 7: Search all topics that have been movedProblemHow would I go about listing all moved topics ?SolutionSearch for the 'moved' meta data.%STARTSECTION{"solution11"}% *Moved topics*: %SEARCH{ "moved.from=~'\w+'" web="all" type="query" separator=", " format="[[$web.$topic]]" nonoise="on" }% %ENDSECTION{"solution11"}%Click to execute Pattern 8: Extract level-1 headingsHow do I go about extracting the first occurance of a level-1 heading?SolutionUse the$pattern() token.
%STARTSECTION{"solution12"}% %SEARCH{ "^---[+][^+][^\r\n]+[\r\n]" type="regex" nonoise="on" header="Headings:" limit="5" format=" * [[$topic][$pattern([\r\n\-+!]+([^\r\n]*?)[\r\n].*)]]" footer="Found $ntopics topics with level-1 headings" }% %ENDSECTION{"solution12"}%Click to execute Related Topics: UserDocumentationCategory, SearchHelp, Macros, FormattedSearch, RegularExpression %STARTSECTION{"click2exec"}% %BUTTON{"Click to execute" onclick="jQuery('#%id%').trigger('refresh')"}% <div class="jqLoader" data-mode="manual" data-web="%INCLUDINGWEB%" data-topic="%INCLUDINGTOPIC%" data-section="%id%" id="%id%"></div> %JQREQUIRE{"loader"}% %ENDSECTION{"click2exec"}% |