73 lines
2.3 KiB
Ruby
73 lines
2.3 KiB
Ruby
module Zero
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# makes it possible to route urls to rack applications
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#
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# This class can be used to build a small rack application which routes
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# requests to the given application.
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# In the URLs it is also possible to use placeholders which then get assigned
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# as variables to the parameters.
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#
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# @example of a simple router
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# router = Zero::Router.new(
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# '/' => WelcomeController,
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# '/posts' => PostController
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# )
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#
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# @example of a router with variables
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# router = Zero::Router.new(
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# '/foo/:id' => FooController
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# )
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class Router
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# match for variables in routes
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VARIABLE_MATCH = %r{:(\w+)[^/]?}
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# the replacement string to make it an regex
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VARIABLE_REGEX = '(?<\1>[\w-]+?)'
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# regex part of the beginning of the line
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REGEX_BEGINNING = '\A'
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# regex part of the end of the line
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REGEX_END = '\Z'
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# environment key to store custom parameters
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ENV_KEY_CUSTOM = 'zero.params.custom'
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# environment key to the path info
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ENV_KEY_PATH_INFO = 'PATH_INFO'
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# create a new router instance
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#
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# @example of a simple router
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# router = Zero::Router.new(
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# '/' => WelcomeController,
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# '/posts' => PostController
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# )
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#
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# @param routes [Hash] a map of URLs to rack compatible applications
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def initialize(routes)
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@routes = {}
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routes.to_a.sort_by(&:first).reverse.each do |route, target|
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@routes[
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Regexp.new(REGEX_BEGINNING +
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route.gsub(VARIABLE_MATCH, VARIABLE_REGEX) +
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REGEX_END)] = target
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end
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end
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# call the router and call the matching application
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#
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# This method has to be called with a rack compatible environment, then the
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# method will find a matching route and call the application.
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# @param env [Hash] a rack environment
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# @return [Array] a rack compatible response
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def call(env)
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env[ENV_KEY_CUSTOM] ||= {}
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@routes.each do |route, target|
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match = route.match(env[ENV_KEY_PATH_INFO])
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if match
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match.names.each_index do |i|
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env[ENV_KEY_CUSTOM][match.names[i]] = match.captures[i]
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end
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return target.call(env)
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end
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end
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[404, {'Content-Type' => 'text/html'}, ['Not found!']]
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end
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end
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end
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