Class: Utopia::Path::Matcher

Inherits:
Object
  • Object
show all
Defined in:
lib/utopia/path/matcher.rb

Overview

Performs structured, efficient, matches against Utopia::Path instances. Supports regular expressions, type-casts and constants.

Examples:

path = Utopia::Path['users/20/edit']
matcher = Utopia::Path::Matcher[users: /users/, id: Integer, action: String]
match_data = matcher.match(path)

Defined Under Namespace

Classes: MatchData

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(patterns = []) ⇒ Matcher

Returns a new instance of Matcher.

Parameters:

  • patterns (Hash<Symbol,Pattern>) (defaults to: []) —

    An ordered list of things to match.



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# File 'lib/utopia/path/matcher.rb', line 47

def initialize(patterns = [])
	@patterns = patterns
end

Class Method Details

.[](patterns) ⇒ Object

Construct a matcher from typed named patterns.



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# File 'lib/utopia/path/matcher.rb', line 54

def self.[](patterns)
	self.new(patterns)
end

Instance Method Details

#coerce(klass, value) ⇒ Object

Coerce.



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# File 'lib/utopia/path/matcher.rb', line 62

def coerce(klass, value)
	if klass == Integer
		Integer(value)
	elsif klass == Float
		Float(value)
	elsif klass == String
		value.to_s
	else
		klass.new(value)
	end
rescue
	return nil
end

#match(path) ⇒ Object

This is a path prefix matching algorithm. The pattern is an array of String, Symbol, Regexp, or nil. The path is an array of String.



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# File 'lib/utopia/path/matcher.rb', line 77

def match(path)
	components = path.to_a
	
	# Can't possibly match if not enough components:
	return nil if components.size < @patterns.size
	
	named_parts = {}
	
	# Try to match each component against the pattern:
	@patterns.each_with_index do |(key, pattern), index|
		component = components[index]
		
		if pattern.is_a? Class
			return nil unless value = coerce(pattern, component)
			
			named_parts[key] = value
		elsif pattern
			if result = pattern.match(component)
				named_parts[key] = result
			else
				# Couldn't match:
				return nil
			end
		else
			# Ignore this part:
			named_parts[key] = component
		end
	end
	
	return MatchData.new(named_parts, components[@patterns.size..-1])
end