Lukas is a library that helps in implementing a custom search query language. It offers some standard features users have come to expect from text driven search like boolean operators and subexpressions.

Lukas can also help you implement custom behaviour for certain keywords, you might for eg. define that keyword "photo" to mean "search for things that have a photo".

The Lukas query parser supports a fairly universal search query standard. It is meant to support the most common search combinations while be fairly simple to use by non-technical users.

It supports the following features:

• Keywords are split on whitespace, eg. Lukas me contains two keywords.
• Keywords can be grouped using quotation marks, eg. "Lukas me" only contains one keyword.
• Keywords can be combined using boolean and, eg. Lukas AND me. This is also the default combination, so Lukas me is the same as Lukas AND me.
• Keywords can be combined using boolean or, eg. Lukas OR me.
• Keywords can be negated using boolean, written as -keyword, eg. -Lukas.
• Combinational logic can be specified using parentheses, eg. Lukas OR (me AND you).
• A keyword can be explicitely marked as belonging to a certain domain, eg. people:Lukas.

Lukas can be installed from packagist through composer. Add a file called composer.json that contains the following:

{
	"require": {
		"oe/lukas": "dev-master"
	}
}

Please bear in mind that Lukas is still in active development. Installing "dev-master" means you are running from trunk. As soon as we hit a stable version it would be best to change "dev-master" to eg. "0.1.0"

Download and install composer:

curl -s https://getcomposer.org/installer | php

Install Lukas:

php composer.phar install

The examples folder contains some samples of what can be parsed and how a certain string will be parsed.

All contributions are welcome. Please fork the repository and send us a pull request. If at all possible include unit tests in the pull request.

To run the unit tests, first download and install composer:

curl -s https://getcomposer.org/installer | php

Create the autoloader:

php composer.phar install

Run the unit tests:

phpunit

Out of the box this will print code coverage information to the commandline. Although this is usefull and tells us how much coverage each class has, it does not show what parts of a class are covered or not. To see that kind of information, please run phpunit like this:

phpunit --coverage-html build/coverage/html