class XML::Reader

Overview

XML::Reader is a parser for XML that iterates a XML document.

require "xml"

reader = XML::Reader.new(<<-XML)
  <message>Hello XML!</message>
  XML
reader.read
reader.name # => "message"
reader.read
reader.value # => "Hello XML!"

This is an alternative approach to XML.parse which parses an entire document into an XML data structure. XML::Reader offers more control and does not need to store the XML document in memory entirely. The latter is especially useful for large documents with the IO-based constructor.

WARNING This type is not concurrency-safe.

Defined in:

xml/reader.cr
xml/reader/type.cr

Constructors

Instance Method Summary

Instance methods inherited from class Reference

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, initialize initialize, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil) same?, to_s(io : IO) : Nil to_s

Constructor methods inherited from class Reference

new new

Instance methods inherited from class Object

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, inspect(io : IO) : Nil
inspect : String inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil!(message)
not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Class methods inherited from class Object

from_json(string_or_io, root : String)
from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml

Constructor Detail

def self.new(str : String, options : XML::ParserOptions = XML::ParserOptions.default) #

Creates a new reader from a string.

See XML::ParserOptions.default for default options.


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def self.new(io : IO, options : XML::ParserOptions = XML::ParserOptions.default) #

Creates a new reader from an IO.

See XML::ParserOptions.default for default options.


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Instance Method Detail

def [](attribute : String) : String #

Gets the attribute content for the attribute given by name. Raises KeyError if attribute is not found.


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def []?(attribute : String) : String | Nil #

Gets the attribute content for the attribute given by name. Returns nil if attribute is not found.


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def attributes_count : Int32 #

Returns attribute count of the node.


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def depth : Int32 #

Returns the current nesting depth of the reader.


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def empty_element? : Bool #

Checks if the node is an empty element.


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def errors : Array(XML::Error) #

Returns the errors reported while parsing.


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def expand : XML::Node #

Expands the node to a XML::Node that can be searched with XPath etc. The returned XML::Node is only valid until the next call to #read.

Raises a XML::Error if the node could not be expanded.


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def expand? : XML::Node | Nil #

Expands the node to a XML::Node that can be searched with XPath etc. The returned XML::Node is only valid until the next call to #read.

Returns nil if the node could not be expanded.


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def has_attributes? : Bool #

Checks if the node has any attributes.


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def move_to_attribute(name : String) : Bool #

Moves to the XML::Reader::Type::ATTRIBUTE with the specified name.


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def move_to_element : Bool #

Moves from the XML::Reader::Type::ATTRIBUTE to its containing XML::Reader::Type::ELEMENT.


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def move_to_first_attribute : Bool #

Moves to the first XML::Reader::Type::ATTRIBUTE of the node.


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def move_to_next_attribute : Bool #

Moves to the next XML::Reader::Type::ATTRIBUTE of the node.


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def name : String #

Returns the name of the node.


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def next : Bool #

Moves the reader to the next node while skipping subtrees.


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def next_sibling : Bool #

Moves the reader to the next sibling node while skipping subtrees.


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def node_type : XML::Reader::Type #

Returns the XML::Reader::Type of the node.


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def read : Bool #

Moves the reader to the next node.


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def read_inner_xml : String #

Returns the node's XML content including subtrees.


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def read_outer_xml : String #

Returns the XML for the node and its content including subtrees.


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def to_unsafe : LibXML::XMLTextReader #

Returns a reference to the underlying LibXML::XMLTextReader.


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def value : String #

Returns the text content of the node.


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