File: README — Documentation for eric-keyword

keyword_search

http://codefluency.rubyforge.org/keyword_search
by Bruce Williams
   Eric Lindvall (negation of terms)

DESCRIPTION:

Generic library to parse GMail-style search strings for keyword/value pairs; supports definition of valid keywords and handling of quoted values.

FEATURES:

The library features a very simple, easy-to-use API.

New in 1.4! Allow negation of terms
Define handlers for supported keywords with blocks
Define the default keyword (values not part of a keyword/value pair)

Development Roadmap:

2.0: Add grouping (will break API backwards compatibility)
Note: As of 1.4, negative terms (terms starting with ‘-’) will be ignored by with.keyword statements that only take one argument. To accept negative terms, provide a second argument to the block |values, positive| to the with.keyword handler.
Note: As of 1.3.0, input to KeywordSearch.search is no longer automatically downcased, allowing for case sensitive keyword and value pairs. If you want case insensitivity, downcase the input before you invoke the method.

SYNOPSIS:

Here’s an example of usage from Rails (though the library is generic, and could presumably be used for any Ruby project)

# Some variables to build up
clauses = []
arguments = []

# Search a string, defining the supported keywords and building up
# the variables in the associated closures

KeywordSearch.search('account has:attachment since:2006-12-03 -description:crazy') do |with|

  with.default_keyword :title

  with.keyword :title do |values|
    clauses << "title like ?"
    arguments << "%#{values.join(' ')}%"
  end

  with.keyword :has do |values|
    clauses << 'has_attachment = true' if values.include?('attachment')
  end

  with.keyword :since do |values|
    date = Date.parse(values.first) # only support one
    clauses << 'created_on >= ?'
    arguments << date.to_s
  end

  with.keyword :description do |values, positive|
    clauses << "description #{'not' unless positive} like ?"
    arguments << "%#{values.join(' ')}%"
  end
end

# Do our search with <tt>clauses</tt> and <tt>arguments</tt>
conditions = [clauses.map{|c| "(#{c})"}.join(' AND ')), *arguments] # simplistic example
results = Message.find(:all, :conditions => conditions)

REQUIREMENTS:

None (echoe if you’re running keyword_search tests or building the gem)

INSTALL:

sudo gem install keyword_search

LICENSE:

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ‘Software’), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.