78 lines
2.1 KiB
Ruby
78 lines
2.1 KiB
Ruby
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module Puppet::Parser::Functions
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newfunction(
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:try_get_value,
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:type => :rvalue,
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:arity => -2,
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:doc => <<-eos
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Looks up into a complex structure of arrays and hashes and returns a value
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or the default value if nothing was found.
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Key can contain slashes to describe path components. The function will go down
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the structure and try to extract the required value.
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$data = {
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'a' => {
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'b' => [
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'b1',
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'b2',
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'b3',
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]
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}
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}
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$value = try_get_value($data, 'a/b/2', 'not_found', '/')
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=> $value = 'b3'
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a -> first hash key
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b -> second hash key
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2 -> array index starting with 0
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not_found -> (optional) will be returned if there is no value or the path did not match. Defaults to nil.
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/ -> (optional) path delimiter. Defaults to '/'.
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In addition to the required "key" argument, "try_get_value" accepts default
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argument. It will be returned if no value was found or a path component is
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missing. And the fourth argument can set a variable path separator.
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eos
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) do |args|
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path_lookup = lambda do |data, path, default|
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debug "Try_get_value: #{path.inspect} from: #{data.inspect}"
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if data.nil?
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debug "Try_get_value: no data, return default: #{default.inspect}"
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break default
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end
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unless path.is_a? Array
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debug "Try_get_value: wrong path, return default: #{default.inspect}"
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break default
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end
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unless path.any?
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debug "Try_get_value: value found, return data: #{data.inspect}"
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break data
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end
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unless data.is_a? Hash or data.is_a? Array
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debug "Try_get_value: incorrect data, return default: #{default.inspect}"
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break default
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end
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key = path.shift
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if data.is_a? Array
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begin
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key = Integer key
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rescue ArgumentError
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debug "Try_get_value: non-numeric path for an array, return default: #{default.inspect}"
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break default
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end
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end
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path_lookup.call data[key], path, default
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end
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data = args[0]
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path = args[1] || ''
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default = args[2]
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separator = args[3] || '/'
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path = path.split separator
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path_lookup.call data, path, default
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end
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end
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