Class: RGeo::WKRep::WKTParser
- Inherits:
-
Object
- Object
- RGeo::WKRep::WKTParser
- Defined in:
- lib/rgeo/wkrep/wkt_parser.rb
Overview
This class provides the functionality of parsing a geometry from WKT (well-known text) format. You may also customize the parser to recognize PostGIS EWKT extensions to the input, or Simple Features Specification 1.2 extensions for Z and M coordinates.
To use this class, create an instance with the desired settings and customizations, and call the parse method.
Configuration options
You must provide each parser with an RGeo::Feature::FactoryGenerator. It should understand the configuration options :srid
, :has_z_coordinate
, and :has_m_coordinate
. You may also pass a specific RGeo::Feature::Factory, or nil to specify the default Cartesian FactoryGenerator.
The following additional options are recognized. These can be passed to the constructor, or set on the object afterwards.
:support_ewkt
-
Activate support for PostGIS EWKT type tags, which appends an “M” to tags to indicate the presence of M but not Z, and also recognizes the SRID prefix. Default is false.
:support_wkt12
-
Activate support for SFS 1.2 extensions to the type codes, which use a “M”, “Z”, or “ZM” token to signal the presence of Z and M values in the data. SFS 1.2 types such as triangle, tin, and polyhedralsurface are NOT yet supported. Default is false.
:strict_wkt11
-
If true, parsing will proceed in SFS 1.1 strict mode, which disallows any values other than X or Y. This has no effect if support_ewkt or support_wkt12 are active. Default is false.
:ignore_extra_tokens
-
If true, extra tokens at the end of the data are ignored. If false (the default), extra tokens will trigger a parse error.
:default_srid
-
A SRID to pass to the factory generator if no SRID is present in the input. Defaults to nil (i.e. don’t specify a SRID).
Instance Method Summary collapse
-
#_check_factory_support ⇒ Object
:nodoc:.
-
#_clean_scanner ⇒ Object
:nodoc:.
-
#_ensure_factory ⇒ Object
:nodoc:.
-
#_expect_token_type(type_) ⇒ Object
:nodoc:.
-
#_next_token ⇒ Object
:nodoc:.
-
#_parse_coords ⇒ Object
:nodoc:.
-
#_parse_geometry_collection ⇒ Object
:nodoc:.
-
#_parse_line_string ⇒ Object
:nodoc:.
-
#_parse_multi_line_string ⇒ Object
:nodoc:.
-
#_parse_multi_point ⇒ Object
:nodoc:.
-
#_parse_multi_polygon ⇒ Object
:nodoc:.
-
#_parse_point(convert_empty_ = false) ⇒ Object
:nodoc:.
-
#_parse_polygon ⇒ Object
:nodoc:.
-
#_parse_type_tag(contained_) ⇒ Object
:nodoc:.
-
#_start_scanner(str_) ⇒ Object
:nodoc:.
-
#exact_factory ⇒ Object
If this parser was given an exact factory, returns it; otherwise returns nil.
-
#factory_generator ⇒ Object
Returns the factory generator.
-
#factory_generator=(value_) ⇒ Object
Sets the factory_generator.
-
#ignore_extra_tokens=(value_) ⇒ Object
Sets the the ignore_extra_tokens flag.
-
#ignore_extra_tokens? ⇒ Boolean
Returns true if this parser ignores extra tokens.
-
#initialize(factory_generator_ = nil, opts_ = {}) ⇒ WKTParser
constructor
Create and configure a WKT parser.
-
#parse(str_) ⇒ Object
Parse the given string, and return a geometry object.
-
#strict_wkt11=(value_) ⇒ Object
Sets the the strict_wkt11 flag.
-
#strict_wkt11? ⇒ Boolean
Returns true if this parser strictly adheres to WKT 1.1.
-
#support_ewkt=(value_) ⇒ Object
Sets the the support_ewkt flag.
-
#support_ewkt? ⇒ Boolean
Returns true if this parser supports EWKT.
-
#support_wkt12=(value_) ⇒ Object
Sets the the support_wkt12 flag.
-
#support_wkt12? ⇒ Boolean
Returns true if this parser supports SFS 1.2 extensions.
-
#to_generate_factory(&block_) ⇒ Object
Sets the factory_generator to the given block.
Constructor Details
#initialize(factory_generator_ = nil, opts_ = {}) ⇒ WKTParser
Create and configure a WKT parser. See the WKTParser documentation for the options that can be passed.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 90 def initialize(factory_generator_=nil, opts_={}) self.factory_generator = factory_generator_ @support_ewkt = opts_[:support_ewkt] ? true : false @support_wkt12 = opts_[:support_wkt12] ? true : false @strict_wkt11 = @support_ewkt || @support_wkt12 ? false : opts_[:strict_wkt11] ? true : false @ignore_extra_tokens = opts_[:ignore_extra_tokens] ? true : false @default_srid = opts_[:default_srid] end |
Instance Method Details
#_check_factory_support ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 205 def _check_factory_support # :nodoc: if @cur_expect_z && !@cur_factory_support_z raise Error::ParseError, "Geometry calls for Z coordinate but factory doesn't support it." end if @cur_expect_m && !@cur_factory_support_m raise Error::ParseError, "Geometry calls for M coordinate but factory doesn't support it." end end |
#_clean_scanner ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 454 def _clean_scanner # :nodoc: @_scanner = nil @cur_token = nil end |
#_ensure_factory ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 215 def _ensure_factory # :nodoc: unless @cur_factory @cur_factory = @factory_generator.call(:srid => @cur_srid, :has_z_coordinate => @cur_expect_z, :has_m_coordinate => @cur_expect_m) @cur_factory_support_z = @cur_factory.property(:has_z_coordinate) ? true : false @cur_factory_support_m = @cur_factory.property(:has_m_coordinate) ? true : false _check_factory_support unless @cur_expect_z.nil? end @cur_factory end |
#_expect_token_type(type_) ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 460 def _expect_token_type(type_) # :nodoc: unless type_ === @cur_token raise Error::ParseError, "#{type_.inspect} expected but #{@cur_token.inspect} found." end end |
#_next_token ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 467 def _next_token # :nodoc: if @_scanner.scan_until(/\(|\)|\[|\]|,|[^\s\(\)\[\],]+/) token_ = @_scanner.matched case token_ when /^[-+]?(\d+(\.\d*)?|\.\d+)(e[-+]?\d+)?$/ @cur_token = token_.to_f when /^[a-z]+$/ @cur_token = token_ when ',' @cur_token = :comma when '(','[' @cur_token = :begin when ']',')' @cur_token = :end else raise Error::ParseError, "Bad token: #{token_.inspect}" end else @cur_token = nil end @cur_token end |
#_parse_coords ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 283 def _parse_coords # :nodoc: _expect_token_type(::Numeric) x_ = @cur_token _next_token _expect_token_type(::Numeric) y_ = @cur_token _next_token extra_ = [] if @cur_expect_z.nil? while ::Numeric === @cur_token extra_ << @cur_token _next_token end num_extras_ = extra_.size @cur_expect_z = num_extras_ > 0 && (!@cur_factory || @cur_factory_support_z) ? true : false num_extras_ -= 1 if @cur_expect_z @cur_expect_m = num_extras_ > 0 && (!@cur_factory || @cur_factory_support_m) ? true : false num_extras_ -= 1 if @cur_expect_m if num_extras_ > 0 raise Error::ParseError, "Found #{extra_.size+2} coordinates, which is too many for this factory." end _ensure_factory else val_ = 0 if @cur_expect_z _expect_token_type(::Numeric) val_ = @cur_token _next_token end if @cur_factory_support_z extra_ << val_ end val_ = 0 if @cur_expect_m _expect_token_type(::Numeric) val_ = @cur_token _next_token end if @cur_factory_support_m extra_ << val_ end end @cur_factory.point(x_, y_, *extra_) end |
#_parse_geometry_collection ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 380 def _parse_geometry_collection # :nodoc: geometries_ = [] if @cur_token != 'empty' _expect_token_type(:begin) _next_token loop do geometries_ << _parse_type_tag(true) break if @cur_token == :end _expect_token_type(:comma) _next_token end end _next_token _ensure_factory.collection(geometries_) end |
#_parse_line_string ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 343 def _parse_line_string # :nodoc: points_ = [] if @cur_token != 'empty' _expect_token_type(:begin) _next_token loop do points_ << _parse_coords break if @cur_token == :end _expect_token_type(:comma) _next_token end end _next_token _ensure_factory.line_string(points_) end |
#_parse_multi_line_string ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 414 def _parse_multi_line_string # :nodoc: line_strings_ = [] if @cur_token != 'empty' _expect_token_type(:begin) _next_token loop do line_strings_ << _parse_line_string break if @cur_token == :end _expect_token_type(:comma) _next_token end end _next_token _ensure_factory.multi_line_string(line_strings_) end |
#_parse_multi_point ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 397 def _parse_multi_point # :nodoc: points_ = [] if @cur_token != 'empty' _expect_token_type(:begin) _next_token loop do points_ << _parse_point break if @cur_token == :end _expect_token_type(:comma) _next_token end end _next_token _ensure_factory.multi_point(points_) end |
#_parse_multi_polygon ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 431 def _parse_multi_polygon # :nodoc: polygons_ = [] if @cur_token != 'empty' _expect_token_type(:begin) _next_token loop do polygons_ << _parse_polygon break if @cur_token == :end _expect_token_type(:comma) _next_token end end _next_token _ensure_factory.multi_polygon(polygons_) end |
#_parse_point(convert_empty_ = false) ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 329 def _parse_point(convert_empty_=false) # :nodoc: if convert_empty_ && @cur_token == 'empty' point_ = _ensure_factory.multi_point([]) else _expect_token_type(:begin) _next_token point_ = _parse_coords _expect_token_type(:end) end _next_token point_ end |
#_parse_polygon ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 360 def _parse_polygon # :nodoc: inner_rings_ = [] if @cur_token == 'empty' outer_ring_ = _ensure_factory.linear_ring([]) else _expect_token_type(:begin) _next_token outer_ring_ = _parse_line_string loop do break if @cur_token == :end _expect_token_type(:comma) _next_token inner_rings_ << _parse_line_string end end _next_token _ensure_factory.polygon(outer_ring_, inner_rings_) end |
#_parse_type_tag(contained_) ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 226 def _parse_type_tag(contained_) # :nodoc: _expect_token_type(::String) if @support_ewkt && @cur_token =~ /^(.+)(m)$/ type_ = $1 zm_ = $2 else type_ = @cur_token zm_ = '' end _next_token if zm_.length == 0 && @support_wkt12 && @cur_token.kind_of?(::String) && @cur_token =~ /^z?m?$/ zm_ = @cur_token _next_token end if zm_.length > 0 || @strict_wkt11 creating_expectation_ = @cur_expect_z.nil? expect_z_ = zm_[0,1] == 'z' ? true : false if @cur_expect_z.nil? @cur_expect_z = expect_z_ elsif expect_z_ != @cur_expect_z raise Error::ParseError, "Surrounding collection has Z but contained geometry doesn't." end expect_m_ = zm_[-1,1] == 'm' ? true : false if @cur_expect_m.nil? @cur_expect_m = expect_m_ else expect_m_ != @cur_expect_m raise Error::ParseError, "Surrounding collection has M but contained geometry doesn't." end if creating_expectation_ if @cur_factory _check_factory_support else _ensure_factory end end end case type_ when 'point' _parse_point(true) when 'linestring' _parse_line_string when 'polygon' _parse_polygon when 'geometrycollection' _parse_geometry_collection when 'multipoint' _parse_multi_point when 'multilinestring' _parse_multi_line_string when 'multipolygon' _parse_multi_polygon else raise Error::ParseError, "Unknown type tag: #{type_.inspect}." end end |
#_start_scanner(str_) ⇒ Object
:nodoc:
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 448 def _start_scanner(str_) # :nodoc: @_scanner = ::StringScanner.new(str_) _next_token end |
#exact_factory ⇒ Object
If this parser was given an exact factory, returns it; otherwise returns nil.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 107 def exact_factory @exact_factory end |
#factory_generator ⇒ Object
Returns the factory generator. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 101 def factory_generator @factory_generator end |
#factory_generator=(value_) ⇒ Object
Sets the factory_generator. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 112 def factory_generator=(value_) if value_.kind_of?(Feature::Factory::Instance) @factory_generator = Feature::FactoryGenerator.single(value_) @exact_factory = value_ elsif value_.respond_to?(:call) @factory_generator = value_ @exact_factory = nil else @factory_generator = Cartesian.method(:preferred_factory) @exact_factory = nil end end |
#ignore_extra_tokens=(value_) ⇒ Object
Sets the the ignore_extra_tokens flag. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 171 def ignore_extra_tokens=(value_) @ignore_extra_tokens = value_ ? true : false end |
#ignore_extra_tokens? ⇒ Boolean
Returns true if this parser ignores extra tokens. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 166 def ignore_extra_tokens? @ignore_extra_tokens end |
#parse(str_) ⇒ Object
Parse the given string, and return a geometry object.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 178 def parse(str_) str_ = str_.downcase @cur_factory = @exact_factory if @cur_factory @cur_factory_support_z = @cur_factory.property(:has_z_coordinate) ? true : false @cur_factory_support_m = @cur_factory.property(:has_m_coordinate) ? true : false end @cur_expect_z = nil @cur_expect_m = nil @cur_srid = @default_srid if @support_ewkt && str_ =~ /^srid=(\d+);/i str_ = $' @cur_srid = $1.to_i end begin _start_scanner(str_) obj_ = _parse_type_tag(false) if @cur_token && !@ignore_extra_tokens raise Error::ParseError, "Extra tokens beginning with #{@cur_token.inspect}." end ensure _clean_scanner end obj_ end |
#strict_wkt11=(value_) ⇒ Object
Sets the the strict_wkt11 flag. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 160 def strict_wkt11=(value_) @strict_wkt11 = value_ ? true : false end |
#strict_wkt11? ⇒ Boolean
Returns true if this parser strictly adheres to WKT 1.1. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 155 def strict_wkt11? @strict_wkt11 end |
#support_ewkt=(value_) ⇒ Object
Sets the the support_ewkt flag. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 138 def support_ewkt=(value_) @support_ewkt = value_ ? true : false end |
#support_ewkt? ⇒ Boolean
Returns true if this parser supports EWKT. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 133 def support_ewkt? @support_ewkt end |
#support_wkt12=(value_) ⇒ Object
Sets the the support_wkt12 flag. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 149 def support_wkt12=(value_) @support_wkt12 = value_ ? true : false end |
#support_wkt12? ⇒ Boolean
Returns true if this parser supports SFS 1.2 extensions. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 144 def support_wkt12? @support_wkt12 end |
#to_generate_factory(&block_) ⇒ Object
Sets the factory_generator to the given block. See WKTParser for details.
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# File 'lib/rgeo/wkrep/wkt_parser.rb', line 127 def to_generate_factory(&block_) self.factory_generator = block_ end |