Google Search Appliance OneBox for Enterprise Developers Guide - Manual (Page 10)

Google Search Appliance: Google OneBox for Enterprise Developer’s Guide 10
Triggering in Response to Specific Keywords
Our directory example uses a keyword trigger, directory. A keyword trigger must be the first word of
the user’s search query, so that the search appliance invokes a module when the search query has the
form directory Bill Smith but not when the search query has the form employee directory. You
can specify multiple keywords by separating each word with a pipe symbol, for example,
directory|phone|contact. If you want the keyword trigger to invoke on a word other than the first
word, use a regular expression.
To define a trigger in the XML configuration file, specify the element as follows:
directory_example
This sample OneBox queries a phone directory
directory
...
To specify multiple keywords, the tag could appear as follows:
directory|dir|d:|phone
This example shows how you can use multiple keywords to provide abbreviated versions of a keyword
or an alternative keyword.
Triggering When the Query Matches a Regular Expression
If you use a regular expression trigger, a search appliance compares the search query to the regular
expression pattern and invokes the OneBox module if the query and the pattern match. OneBox
supports regular expressions as defined by the Perl Compatible Regular Expressions library (PCRE) at
http://perldoc.perl.org/perlre.html . Enclose each expression in parentheses. You can separate multiple
expressions with a space, for example,
(i) (.*) report
ignores case and matches any word before report.
The table below lists common regular expression rules.
The following are examples of the common regular expression rules:
• The regular expression status (.*) matches a query if the user types status and a project name.
• The regular expression distance from (.*) to (.*) matches a query such as distance from
Paris to Rome.
• The regular expression \d+ matches a query such as 123.
Syntax Description
(.*) Match any character zero or more times; that is, match any word
(.?) Match a single character
(\d+) Match a digit one or more times
(i) Ignore case
([a-z]+) Match lowercase letters one or more times
(?: values) Match specific keyword values