Class: Nokogiri::XML::Reader

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/nokogiri/xml/reader.rb,
ext/nokogiri/xml_reader.c

Overview

Nokogiri::XML::Reader parses an XML document similar to the way a cursor would move. The Reader is given an XML document, and yields nodes to an each block.

The Reader parser might be good for when you need the speed and low memory usage of the SAX parser, but do not want to write a Document handler.

Here is an example of usage:

reader = Nokogiri::XML::Reader(<<-eoxml)
  <x xmlns:tenderlove='http://tenderlovemaking.com/'>
    <tenderlove:foo awesome='true'>snuggles!</tenderlove:foo>
  </x>
eoxml

reader.each do |node|

  # node is an instance of Nokogiri::XML::Reader
  puts node.name

end

⚠ Nokogiri::XML::Reader#each can only be called once! Once the cursor moves through the entire document, you must parse the document again. It may be better to capture all information you need during a single iteration.

⚠ libxml2 does not support error recovery in the Reader parser. The ‘RECOVER` ParseOption is ignored. If a syntax error is encountered during parsing, an exception will be raised.

Constant Summary collapse

TYPE_NONE = 
0
TYPE_ELEMENT =

Element node type

1
TYPE_ATTRIBUTE =

Attribute node type

2
TYPE_TEXT =

Text node type

3
TYPE_CDATA =

CDATA node type

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TYPE_ENTITY_REFERENCE =

Entity Reference node type

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TYPE_ENTITY =

Entity node type

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TYPE_PROCESSING_INSTRUCTION =

PI node type

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TYPE_COMMENT =

Comment node type

8
TYPE_DOCUMENT =

Document node type

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TYPE_DOCUMENT_TYPE =

Document Type node type

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TYPE_DOCUMENT_FRAGMENT =

Document Fragment node type

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TYPE_NOTATION =

Notation node type

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TYPE_WHITESPACE =

Whitespace node type

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TYPE_SIGNIFICANT_WHITESPACE =

Significant Whitespace node type

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TYPE_END_ELEMENT =

Element end node type

15
TYPE_END_ENTITY =

Entity end node type

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TYPE_XML_DECLARATION =

XML Declaration node type

17

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#errors ⇒ Object

A list of errors encountered while parsing



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# File 'lib/nokogiri/xml/reader.rb', line 73

def errors
  @errors
end

#source ⇒ Object (readonly)

The XML source



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# File 'lib/nokogiri/xml/reader.rb', line 76

def source
  @source
end

Class Method Details

.from_io(io, url = nil, encoding = nil, options = 0) ⇒ Object

Create a new reader that parses io



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# File 'ext/nokogiri/xml_reader.c', line 658

static VALUE
from_io(int argc, VALUE *argv, VALUE klass)
{
  VALUE rb_io, rb_url, encoding, rb_options;
  xmlTextReaderPtr reader;
  const char *c_url      = NULL;
  const char *c_encoding = NULL;
  int c_options           = 0;
  VALUE rb_reader, args[3];

  rb_scan_args(argc, argv, "13", &rb_io, &rb_url, &encoding, &rb_options);

  if (!RTEST(rb_io)) { rb_raise(rb_eArgError, "io cannot be nil"); }
  if (RTEST(rb_url)) { c_url = StringValueCStr(rb_url); }
  if (RTEST(encoding)) { c_encoding = StringValueCStr(encoding); }
  if (RTEST(rb_options)) { c_options = (int)NUM2INT(rb_options); }

  reader = xmlReaderForIO(
             (xmlInputReadCallback)noko_io_read,
             (xmlInputCloseCallback)noko_io_close,
             (void *)rb_io,
             c_url,
             c_encoding,
             c_options
           );

  if (reader == NULL) {
    xmlFreeTextReader(reader);
    rb_raise(rb_eRuntimeError, "couldn't create a parser");
  }

  rb_reader = TypedData_Wrap_Struct(klass, &xml_text_reader_type, reader);
  args[0] = rb_io;
  args[1] = rb_url;
  args[2] = encoding;
  rb_obj_call_init(rb_reader, 3, args);

  return rb_reader;
}

.from_memory(string, url = nil, encoding = nil, options = 0) ⇒ Object

Create a new reader that parses string



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# File 'ext/nokogiri/xml_reader.c', line 613

static VALUE
from_memory(int argc, VALUE *argv, VALUE klass)
{
  VALUE rb_buffer, rb_url, encoding, rb_options;
  xmlTextReaderPtr reader;
  const char *c_url      = NULL;
  const char *c_encoding = NULL;
  int c_options           = 0;
  VALUE rb_reader, args[3];

  rb_scan_args(argc, argv, "13", &rb_buffer, &rb_url, &encoding, &rb_options);

  if (!RTEST(rb_buffer)) { rb_raise(rb_eArgError, "string cannot be nil"); }
  if (RTEST(rb_url)) { c_url = StringValueCStr(rb_url); }
  if (RTEST(encoding)) { c_encoding = StringValueCStr(encoding); }
  if (RTEST(rb_options)) { c_options = (int)NUM2INT(rb_options); }

  reader = xmlReaderForMemory(
             StringValuePtr(rb_buffer),
             (int)RSTRING_LEN(rb_buffer),
             c_url,
             c_encoding,
             c_options
           );

  if (reader == NULL) {
    xmlFreeTextReader(reader);
    rb_raise(rb_eRuntimeError, "couldn't create a parser");
  }

  rb_reader = TypedData_Wrap_Struct(klass, &xml_text_reader_type, reader);
  args[0] = rb_buffer;
  args[1] = rb_url;
  args[2] = encoding;
  rb_obj_call_init(rb_reader, 3, args);

  return rb_reader;
}

Instance Method Details

#attribute(name) ⇒ Object

Get the value of attribute named name



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# File 'ext/nokogiri/xml_reader.c', line 266

static VALUE
reader_attribute(VALUE self, VALUE name)
{
  xmlTextReaderPtr reader;
  xmlChar *value ;
  VALUE rb_value;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);

  if (NIL_P(name)) { return Qnil; }
  name = StringValue(name) ;

  value = xmlTextReaderGetAttribute(reader, (xmlChar *)StringValueCStr(name));
  if (value == NULL) { return Qnil; }

  rb_value = NOKOGIRI_STR_NEW2(value);
  xmlFree(value);
  return rb_value;
}

#attribute_at(index) ⇒ Object

Get the value of attribute at index



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# File 'ext/nokogiri/xml_reader.c', line 237

static VALUE
attribute_at(VALUE self, VALUE index)
{
  xmlTextReaderPtr reader;
  xmlChar *value;
  VALUE rb_value;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);

  if (NIL_P(index)) { return Qnil; }
  index = rb_Integer(index);

  value = xmlTextReaderGetAttributeNo(
            reader,
            (int)NUM2INT(index)
          );
  if (value == NULL) { return Qnil; }

  rb_value = NOKOGIRI_STR_NEW2(value);
  xmlFree(value);
  return rb_value;
}

#attribute_count ⇒ Object

Get the number of attributes for the current node



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# File 'ext/nokogiri/xml_reader.c', line 292

static VALUE
attribute_count(VALUE self)
{
  xmlTextReaderPtr reader;
  int count;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  count = xmlTextReaderAttributeCount(reader);
  if (count == -1) { return Qnil; }

  return INT2NUM(count);
}

#attribute_hash ⇒ Object

:call-seq: attribute_hash() → Hash<String ⇒ String>

Get the attributes of the current node as a Hash of names and values.

See related: #attributes and #namespaces



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# File 'ext/nokogiri/xml_reader.c', line 182

static VALUE
rb_xml_reader_attribute_hash(VALUE rb_reader)
{
  VALUE rb_attributes = rb_hash_new();
  xmlTextReaderPtr c_reader;
  xmlNodePtr c_node;
  xmlAttrPtr c_property;
  VALUE rb_errors;

  TypedData_Get_Struct(rb_reader, xmlTextReader, &xml_text_reader_type, c_reader);

  if (!has_attributes(c_reader)) {
    return rb_attributes;
  }

  rb_errors = rb_funcall(rb_reader, rb_intern("errors"), 0);

  xmlSetStructuredErrorFunc((void *)rb_errors, noko__error_array_pusher);
  c_node = xmlTextReaderExpand(c_reader);
  xmlSetStructuredErrorFunc(NULL, NULL);

  if (c_node == NULL) {
    if (RARRAY_LEN(rb_errors) > 0) {
      VALUE rb_error = rb_ary_entry(rb_errors, 0);
      VALUE exception_message = rb_funcall(rb_error, rb_intern("to_s"), 0);
      rb_exc_raise(rb_class_new_instance(1, &exception_message, cNokogiriXmlSyntaxError));
    }
    return Qnil;
  }

  c_property = c_node->properties;
  while (c_property != NULL) {
    VALUE rb_name = NOKOGIRI_STR_NEW2(c_property->name);
    VALUE rb_value = Qnil;
    xmlChar *c_value = xmlNodeGetContent((xmlNode *)c_property);

    if (c_value) {
      rb_value = NOKOGIRI_STR_NEW2(c_value);
      xmlFree(c_value);
    }

    rb_hash_aset(rb_attributes, rb_name, rb_value);

    c_property = c_property->next;
  }

  return rb_attributes;
}

#attributes ⇒ Object

Get the attributes and namespaces of the current node as a Hash.

This is the union of Reader#attribute_hash and Reader#namespaces

Returns

(Hash<String, String>) Attribute names and values, and namespace prefixes and hrefs.



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# File 'lib/nokogiri/xml/reader.rb', line 93

def attributes
  attribute_hash.merge(namespaces)
end

#attributes? ⇒ Boolean

Does this node have attributes?

Returns:

  • (Boolean) 


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# File 'ext/nokogiri/xml_reader.c', line 121

static VALUE
attributes_eh(VALUE self)
{
  xmlTextReaderPtr reader;
  int eh;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  eh = has_attributes(reader);
  if (eh == 0) { return Qfalse; }
  if (eh == 1) { return Qtrue; }

  return Qnil;
}

#base_uri ⇒ Object

base_uri

Get the xml:base of the node



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# File 'ext/nokogiri/xml_reader.c', line 463

static VALUE
rb_xml_reader_base_uri(VALUE rb_reader)
{
  VALUE rb_base_uri;
  xmlTextReaderPtr c_reader;
  xmlChar *c_base_uri;

  TypedData_Get_Struct(rb_reader, xmlTextReader, &xml_text_reader_type, c_reader);

  c_base_uri = xmlTextReaderBaseUri(c_reader);
  if (c_base_uri == NULL) {
    return Qnil;
  }

  rb_base_uri = NOKOGIRI_STR_NEW2(c_base_uri);
  xmlFree(c_base_uri);

  return rb_base_uri;
}

#default? ⇒ Boolean

Was an attribute generated from the default value in the DTD or schema?

Returns:

  • (Boolean) 


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# File 'ext/nokogiri/xml_reader.c', line 81

static VALUE
default_eh(VALUE self)
{
  xmlTextReaderPtr reader;
  int eh;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  eh = xmlTextReaderIsDefault(reader);
  if (eh == 0) { return Qfalse; }
  if (eh == 1) { return Qtrue; }

  return Qnil;
}

#depth ⇒ Object

Get the depth of the node



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# File 'ext/nokogiri/xml_reader.c', line 311

static VALUE
depth(VALUE self)
{
  xmlTextReaderPtr reader;
  int depth;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  depth = xmlTextReaderDepth(reader);
  if (depth == -1) { return Qnil; }

  return INT2NUM(depth);
}

#each ⇒ Object

Move the cursor through the document yielding the cursor to the block



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# File 'lib/nokogiri/xml/reader.rb', line 99

def each
  while (cursor = read)
    yield cursor
  end
end

#empty_element?(#) ⇒ Boolean Also known as: self_closing?

Returns true if the current node is empty, otherwise false.

Returns:

  • (Boolean) 


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# File 'ext/nokogiri/xml_reader.c', line 704

static VALUE
empty_element_p(VALUE self)
{
  xmlTextReaderPtr reader;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);

  if (xmlTextReaderIsEmptyElement(reader)) {
    return Qtrue;
  }

  return Qfalse;
}

#encoding ⇒ Object 



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# File 'ext/nokogiri/xml_reader.c', line 718

static VALUE
rb_xml_reader_encoding(VALUE rb_reader)
{
  xmlTextReaderPtr c_reader;
  const char *parser_encoding;
  VALUE constructor_encoding;

  TypedData_Get_Struct(rb_reader, xmlTextReader, &xml_text_reader_type, c_reader);
  parser_encoding = (const char *)xmlTextReaderConstEncoding(c_reader);
  if (parser_encoding) {
    return NOKOGIRI_STR_NEW2(parser_encoding);
  }

  constructor_encoding = rb_iv_get(rb_reader, "@encoding");
  if (RTEST(constructor_encoding)) {
    return constructor_encoding;
  }

  return Qnil;
}

#inner_xml ⇒ Object

Read the contents of the current node, including child nodes and markup. Returns a utf-8 encoded string.



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# File 'ext/nokogiri/xml_reader.c', line 562

static VALUE
inner_xml(VALUE self)
{
  xmlTextReaderPtr reader;
  xmlChar *value;
  VALUE str;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);

  value = xmlTextReaderReadInnerXml(reader);

  str = Qnil;
  if (value) {
    str = NOKOGIRI_STR_NEW2((char *)value);
    xmlFree(value);
  }

  return str;
}

#lang ⇒ Object

Get the xml:lang scope within which the node resides.



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# File 'ext/nokogiri/xml_reader.c', line 349

static VALUE
lang(VALUE self)
{
  xmlTextReaderPtr reader;
  const char *lang;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  lang = (const char *)xmlTextReaderConstXmlLang(reader);
  if (lang == NULL) { return Qnil; }

  return NOKOGIRI_STR_NEW2(lang);
}

#local_name ⇒ Object

Get the local name of the node



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# File 'ext/nokogiri/xml_reader.c', line 425

static VALUE
local_name(VALUE self)
{
  xmlTextReaderPtr reader;
  const char *name;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  name = (const char *)xmlTextReaderConstLocalName(reader);
  if (name == NULL) { return Qnil; }

  return NOKOGIRI_STR_NEW2(name);
}

#name ⇒ Object

Get the name of the node. Returns a utf-8 encoded string.



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# File 'ext/nokogiri/xml_reader.c', line 444

static VALUE
name(VALUE self)
{
  xmlTextReaderPtr reader;
  const char *name;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  name = (const char *)xmlTextReaderConstName(reader);
  if (name == NULL) { return Qnil; }

  return NOKOGIRI_STR_NEW2(name);
}

#namespace_uri ⇒ Object

Get the URI defining the namespace associated with the node



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# File 'ext/nokogiri/xml_reader.c', line 406

static VALUE
namespace_uri(VALUE self)
{
  xmlTextReaderPtr reader;
  const char *uri;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  uri = (const char *)xmlTextReaderConstNamespaceUri(reader);
  if (uri == NULL) { return Qnil; }

  return NOKOGIRI_STR_NEW2(uri);
}

#namespaces ⇒ Object

Get a hash of namespaces for this Node



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# File 'ext/nokogiri/xml_reader.c', line 141

static VALUE
rb_xml_reader_namespaces(VALUE rb_reader)
{
  VALUE rb_namespaces = rb_hash_new() ;
  xmlTextReaderPtr c_reader;
  xmlNodePtr c_node;
  VALUE rb_errors;

  TypedData_Get_Struct(rb_reader, xmlTextReader, &xml_text_reader_type, c_reader);

  if (! has_attributes(c_reader)) {
    return rb_namespaces ;
  }

  rb_errors = rb_funcall(rb_reader, rb_intern("errors"), 0);

  xmlSetStructuredErrorFunc((void *)rb_errors, noko__error_array_pusher);
  c_node = xmlTextReaderExpand(c_reader);
  xmlSetStructuredErrorFunc(NULL, NULL);

  if (c_node == NULL) {
    if (RARRAY_LEN(rb_errors) > 0) {
      VALUE rb_error = rb_ary_entry(rb_errors, 0);
      VALUE exception_message = rb_funcall(rb_error, rb_intern("to_s"), 0);
      rb_exc_raise(rb_class_new_instance(1, &exception_message, cNokogiriXmlSyntaxError));
    }
    return Qnil;
  }

  Nokogiri_xml_node_namespaces(c_node, rb_namespaces);

  return rb_namespaces ;
}

#node_type ⇒ Object

Get the type of readers current node



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# File 'ext/nokogiri/xml_reader.c', line 503

static VALUE
node_type(VALUE self)
{
  xmlTextReaderPtr reader;
  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  return INT2NUM(xmlTextReaderNodeType(reader));
}

#outer_xml ⇒ Object

Read the current node and its contents, including child nodes and markup. Returns a utf-8 encoded string.



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# File 'ext/nokogiri/xml_reader.c', line 589

static VALUE
outer_xml(VALUE self)
{
  xmlTextReaderPtr reader;
  xmlChar *value;
  VALUE str = Qnil;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);

  value = xmlTextReaderReadOuterXml(reader);

  if (value) {
    str = NOKOGIRI_STR_NEW2((char *)value);
    xmlFree(value);
  }
  return str;
}

#prefix ⇒ Object

Get the shorthand reference to the namespace associated with the node.



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# File 'ext/nokogiri/xml_reader.c', line 387

static VALUE
prefix(VALUE self)
{
  xmlTextReaderPtr reader;
  const char *prefix;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  prefix = (const char *)xmlTextReaderConstPrefix(reader);
  if (prefix == NULL) { return Qnil; }

  return NOKOGIRI_STR_NEW2(prefix);
}

#read ⇒ Object

Move the Reader forward through the XML document.



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# File 'ext/nokogiri/xml_reader.c', line 517

static VALUE
read_more(VALUE rb_reader)
{
  xmlTextReaderPtr c_reader;
  libxmlStructuredErrorHandlerState handler_state;

  TypedData_Get_Struct(rb_reader, xmlTextReader, &xml_text_reader_type, c_reader);

  VALUE rb_errors = rb_funcall(rb_reader, rb_intern("errors"), 0);
  noko__structured_error_func_save_and_set(&handler_state, (void *)rb_errors, noko__error_array_pusher);

  int status = xmlTextReaderRead(c_reader);

  noko__structured_error_func_restore(&handler_state);

  xmlDocPtr c_document = xmlTextReaderCurrentDoc(c_reader);
  if (c_document && c_document->encoding == NULL) {
    VALUE constructor_encoding = rb_iv_get(rb_reader, "@encoding");
    if (RTEST(constructor_encoding)) {
      c_document->encoding = xmlStrdup(BAD_CAST StringValueCStr(constructor_encoding));
    } else {
      rb_iv_set(rb_reader, "@encoding", NOKOGIRI_STR_NEW2("UTF-8"));
      c_document->encoding = xmlStrdup(BAD_CAST "UTF-8");
    }
  }

  if (status == 1) { return rb_reader; }
  if (status == 0) { return Qnil; }

  /* if we're here, there was an error */
  VALUE exception = rb_funcall(cNokogiriXmlSyntaxError, rb_intern("aggregate"), 1, rb_errors);
  if (RB_TEST(exception)) {
    rb_exc_raise(exception);
  } else {
    rb_raise(rb_eRuntimeError, "Error pulling: %d", status);
  }
}

#state ⇒ Object

Get the state of the reader



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# File 'ext/nokogiri/xml_reader.c', line 489

static VALUE
state(VALUE self)
{
  xmlTextReaderPtr reader;
  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  return INT2NUM(xmlTextReaderReadState(reader));
}

#value ⇒ Object

Get the text value of the node if present. Returns a utf-8 encoded string.



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# File 'ext/nokogiri/xml_reader.c', line 368

static VALUE
value(VALUE self)
{
  xmlTextReaderPtr reader;
  const char *value;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  value = (const char *)xmlTextReaderConstValue(reader);
  if (value == NULL) { return Qnil; }

  return NOKOGIRI_STR_NEW2(value);
}

#value? ⇒ Boolean

Does this node have a text value?

Returns:

  • (Boolean) 


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# File 'ext/nokogiri/xml_reader.c', line 101

static VALUE
value_eh(VALUE self)
{
  xmlTextReaderPtr reader;
  int eh;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  eh = xmlTextReaderHasValue(reader);
  if (eh == 0) { return Qfalse; }
  if (eh == 1) { return Qtrue; }

  return Qnil;
}

#xml_version ⇒ Object

Get the XML version of the document being read



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# File 'ext/nokogiri/xml_reader.c', line 330

static VALUE
xml_version(VALUE self)
{
  xmlTextReaderPtr reader;
  const char *version;

  TypedData_Get_Struct(self, xmlTextReader, &xml_text_reader_type, reader);
  version = (const char *)xmlTextReaderConstXmlVersion(reader);
  if (version == NULL) { return Qnil; }

  return NOKOGIRI_STR_NEW2(version);
}