JezK
Edit File: handler.rb
# frozen_string_literal: true module Psych ### # Psych::Handler is an abstract base class that defines the events used # when dealing with Psych::Parser. Clients who want to use Psych::Parser # should implement a class that inherits from Psych::Handler and define # events that they can handle. # # Psych::Handler defines all events that Psych::Parser can possibly send to # event handlers. # # See Psych::Parser for more details class Handler ### # Configuration options for dumping YAML. class DumperOptions attr_accessor :line_width, :indentation, :canonical def initialize @line_width = 0 @indentation = 2 @canonical = false end end # Default dumping options OPTIONS = DumperOptions.new # Events that a Handler should respond to. EVENTS = [ :alias, :empty, :end_document, :end_mapping, :end_sequence, :end_stream, :scalar, :start_document, :start_mapping, :start_sequence, :start_stream ] ### # Called with +encoding+ when the YAML stream starts. This method is # called once per stream. A stream may contain multiple documents. # # See the constants in Psych::Parser for the possible values of +encoding+. def start_stream encoding end ### # Called when the document starts with the declared +version+, # +tag_directives+, if the document is +implicit+. # # +version+ will be an array of integers indicating the YAML version being # dealt with, +tag_directives+ is a list of tuples indicating the prefix # and suffix of each tag, and +implicit+ is a boolean indicating whether # the document is started implicitly. # # === Example # # Given the following YAML: # # %YAML 1.1 # %TAG ! tag:tenderlovemaking.com,2009: # --- !squee # # The parameters for start_document must be this: # # version # => [1, 1] # tag_directives # => [["!", "tag:tenderlovemaking.com,2009:"]] # implicit # => false def start_document version, tag_directives, implicit end ### # Called with the document ends. +implicit+ is a boolean value indicating # whether or not the document has an implicit ending. # # === Example # # Given the following YAML: # # --- # hello world # # +implicit+ will be true. Given this YAML: # # --- # hello world # ... # # +implicit+ will be false. def end_document implicit end ### # Called when an alias is found to +anchor+. +anchor+ will be the name # of the anchor found. # # === Example # # Here we have an example of an array that references itself in YAML: # # --- &ponies # - first element # - *ponies # # &ponies is the anchor, *ponies is the alias. In this case, alias is # called with "ponies". def alias anchor end ### # Called when a scalar +value+ is found. The scalar may have an # +anchor+, a +tag+, be implicitly +plain+ or implicitly +quoted+ # # +value+ is the string value of the scalar # +anchor+ is an associated anchor or nil # +tag+ is an associated tag or nil # +plain+ is a boolean value # +quoted+ is a boolean value # +style+ is an integer indicating the string style # # See the constants in Psych::Nodes::Scalar for the possible values of # +style+ # # === Example # # Here is a YAML document that exercises most of the possible ways this # method can be called: # # --- # - !str "foo" # - &anchor fun # - many # lines # - | # many # newlines # # The above YAML document contains a list with four strings. Here are # the parameters sent to this method in the same order: # # # value anchor tag plain quoted style # ["foo", nil, "!str", false, false, 3 ] # ["fun", "anchor", nil, true, false, 1 ] # ["many lines", nil, nil, true, false, 1 ] # ["many\nnewlines\n", nil, nil, false, true, 4 ] # def scalar value, anchor, tag, plain, quoted, style end ### # Called when a sequence is started. # # +anchor+ is the anchor associated with the sequence or nil. # +tag+ is the tag associated with the sequence or nil. # +implicit+ a boolean indicating whether or not the sequence was implicitly # started. # +style+ is an integer indicating the list style. # # See the constants in Psych::Nodes::Sequence for the possible values of # +style+. # # === Example # # Here is a YAML document that exercises most of the possible ways this # method can be called: # # --- # - !!seq [ # a # ] # - &pewpew # - b # # The above YAML document consists of three lists, an outer list that # contains two inner lists. Here is a matrix of the parameters sent # to represent these lists: # # # anchor tag implicit style # [nil, nil, true, 1 ] # [nil, "tag:yaml.org,2002:seq", false, 2 ] # ["pewpew", nil, true, 1 ] def start_sequence anchor, tag, implicit, style end ### # Called when a sequence ends. def end_sequence end ### # Called when a map starts. # # +anchor+ is the anchor associated with the map or +nil+. # +tag+ is the tag associated with the map or +nil+. # +implicit+ is a boolean indicating whether or not the map was implicitly # started. # +style+ is an integer indicating the mapping style. # # See the constants in Psych::Nodes::Mapping for the possible values of # +style+. # # === Example # # Here is a YAML document that exercises most of the possible ways this # method can be called: # # --- # k: !!map { hello: world } # v: &pewpew # hello: world # # The above YAML document consists of three maps, an outer map that contains # two inner maps. Below is a matrix of the parameters sent in order to # represent these three maps: # # # anchor tag implicit style # [nil, nil, true, 1 ] # [nil, "tag:yaml.org,2002:map", false, 2 ] # ["pewpew", nil, true, 1 ] def start_mapping anchor, tag, implicit, style end ### # Called when a map ends def end_mapping end ### # Called when an empty event happens. (Which, as far as I can tell, is # never). def empty end ### # Called when the YAML stream ends def end_stream end ### # Called before each event with line/column information. def event_location(start_line, start_column, end_line, end_column) end ### # Is this handler a streaming handler? def streaming? false end end end