class Rack::NestedParams::UrlEncodedPairParser
Constants
- BRACKETED_KEY_REGEXP
- KEY_REGEXP
Attributes
parent[R]
result[R]
top[R]
Public Class Methods
new(pairs = [])
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Calls superclass method
# File lib/rack/contrib/nested_params.rb, line 52 def initialize(pairs = []) super('') @result = {} pairs.each { |key, value| parse(key, value) } end
Public Instance Methods
parse(key, value)
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Parse the query string
# File lib/rack/contrib/nested_params.rb, line 62 def parse(key, value) self.string = key @top, @parent = result, nil # First scan the bare key key = scan(KEY_REGEXP) or return key = post_key_check(key) # Then scan as many nestings as present until eos? r = scan(BRACKETED_KEY_REGEXP) or return key = self[1] key = post_key_check(key) end bind(key, value) end
Private Instance Methods
bind(key, value)
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Bind a key (which may be nil for items in an array) to the provided value.
# File lib/rack/contrib/nested_params.rb, line 113 def bind(key, value) if top.is_a? Array if key if top[-1].is_a?(Hash) && ! top[-1].key?(key) top[-1][key] = value else top << {key => value} end push top.last return top[key] else top << value return value end elsif top.is_a? Hash key = CGI.unescape(key) parent << (@top = {}) if top.key?(key) && parent.is_a?(Array) top[key] ||= value return top[key] else raise ArgumentError, "Don't know what to do: top is #{top.inspect}" end end
container(key, klass)
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Add a container to the stack.
# File lib/rack/contrib/nested_params.rb, line 100 def container(key, klass) type_conflict! klass, top[key] if top.is_a?(Hash) && top.key?(key) && ! top[key].is_a?(klass) value = bind(key, klass.new) type_conflict! klass, value unless value.is_a?(klass) push(value) end
post_key_check(key)
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After we see a key, we must look ahead to determine our next action. Cases:
[] follows the key. Then the value must be an array. = follows the key. (A value comes next) & or the end of string follows the key. Then the key is a flag. otherwise, a hash follows the key.
# File lib/rack/contrib/nested_params.rb, line 87 def post_key_check(key) if scan(/\[\]/) # a[b][] indicates that b is an array container(key, Array) nil elsif check(/\[[^\]]/) # a[b] indicates that a is a hash container(key, Hash) nil else # End of key? We do nothing. key end end
push(value)
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Push a value onto the 'stack', which is actually only the top 2 items.
# File lib/rack/contrib/nested_params.rb, line 108 def push(value) @parent, @top = @top, value end
type_conflict!(klass, value)
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# File lib/rack/contrib/nested_params.rb, line 137 def type_conflict!(klass, value) raise TypeError, "Conflicting types for parameter containers. Expected an instance of #{klass} but found an instance of #{value.class}. This can be caused by colliding Array and Hash parameters like qs[]=value&qs[key]=value. (The parameters received were #{value.inspect}.)" end