SID-01372: Keyword search among children of a particular topic

Status:	Answered	TWiki version:	5.1.0	Perl version:	5.0
Category:	CategorySearch	Server OS:	Debian 6.0	Last update:	14 years ago

How would I define a keyword search that only searches topics that are children of a given topic? As far as I can tell, there is not a parameter for standard keyword search that allows for this kind of specification.

I realize that I can use the topic="" and excludetopic="" parameters to specify the search space but I'm wondering if there's a more straightforward way to limit the keyword search just to a set of children with a common parent.

-- JordanEcker - 2012-01-09

Discussion and Answer

I'm trying to use a nested search to accomplish this. So far I've put together the following:

%SEARCH{"foobar" type="keyword" topic="$percntSEARCH{$quotparent.name='ParentTopic'$quot separator=$quot, $quot format=$quot$ltnop$gt$topic$quot type=$quotquery$quot}$percnt"}%

The goal is to have the inner search spit out a comma-separated, non-link (plain text) list of child topics of ParentTopic. Then the outer search looks for the search string "foobar" in this list of topics.

When I pull out the inner search and run it by itself to test it (with all $ escape variables replaced with their corresponding special characters), I get the list of ParentTopic's children as expected. However, the two searches nested together do not seem to produce the desired result. I'm not sure where I'm going wrong...

-- JordanEcker - 2012-01-09

I think I found the issue... Looks like the inner search was actually returning search header text and number of results along with the list of children. Turning nonoise="on" for the inner search gets rid of that extra stuff and seems to make the nesting work as expected.

Now, how would I further nest this structure inside an %IF{}% construct? How does escaping work for a clause that is doubly nested?

-- JordanEcker - 2012-01-09

Here is the code I'm working with if anyone can help:

<form><input type="text" name="search_string" size="60" />&nbsp;&nbsp;<input type="submit" value="Search" /></form>

%IF{"defined 'search_string'"
       then="%SEARCH{
                                   "%URLPARAM{search_string}%"
                                   type="keyword" 
                                   topic="%SEARCH{"parent.name='KnownIssues'" format="$topic" separator=", " nonoise="on" excludetopic="*Form, *Template, *Resolutions*" type="query"}%"
       }%"
       else="search_string not defined"
}%

The SEARCH inside the then-branch of the IF has another search nested in its topic parameter, and this nested structure works when I test it by itself (outside of the IF). When I put it in the IF, I get "<span class=" which seems to indicate that I haven't nested something correctly.

I'm confused about why the SEARCH within the SEARCH works without using any escaping, but I need to escape when dropping these in an IF? If this is the case, how do I escape correctly to make this structure work as intended?

-- JordanEcker - 2012-01-10

A "<span class=" indicates an early termination of a parameter. For example "%URLPARAM{search_string}%" embedded in another variable as a parameter could resolve in a string that has a double quote, which terminates the parameter early. A WikiWord for example resolves to a "<span class=" type link. You need to escape the URLPARAM string, see VarURLPARAM.

A variable within another variable gets evaluated first. So your inner SEARCH in topic="" gets evaluated before the SEARCH in then="". I believe the IF gets evaluated last. You can delay the then="" and else="" of IF by escaping % with $percnt. By delaying the SEARCHes you need to escape the " as well using \". So try:

then="$searchSEARCH{ \"$percntURLPARAM{search_string}$percnt\" ...

-- PeterThoeny - 2012-01-10

Thanks Peter for your help.

I made the changes you suggested to the then-branch value (escaping the outer search SEARCH and URLPARAM) and played around with escaping the inner SEARCH until I thought to try not escaping the inner search at all, which worked:

%IF{"defined 'search_string'"
    then="$percntSEARCH{
                  \"$percntURLPARAM{search_string}$percnt\"
                  type=\"keyword\" 
                  topic=\"%SEARCH{"parent.name='KnownIssues'" format="$topic" separator=", " nonoise="on" type="query"}%\"
         }$percnt"
    else="search_string not defined"
}%

I'm not sure I completely understand why this works. Why does the first double-quote after the inner SEARCH not terminate the then-branch parameter of the IF?

-- JordanEcker - 2012-01-10

Because of the inside-out evaluation order, all that IF sees is the result of the inner SEARCH.

-- PeterThoeny - 2012-01-11

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