Nokogiri::XML::Reader
class Nokogiri::XML::Reader
The Reader parser allows you to effectively pull parse an XML document. Once instantiated, call #each to iterate over each node. Note that you may only iterate over the document once!
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.
Here is an example of usage:
reader = Nokogiri::XML::Reader(" <x xmlns:tenderlove='http://tenderlovemaking.com/'> <tenderlove:foo awesome='true'>snuggles!</tenderlove:foo> </x> ") reader.each do |node| # node is an instance of Nokogiri::XML::Reader puts node.name end
Note that #each can only be called once!! Once the cursor moves through the entire document, you must parse the document again. So make sure that you capture any information you need during the first iteration.
The Reader parser is good for when you need the speed of a SAX parser, but do not want to write a Document handler.
Constants
- TYPE_ATTRIBUTE
-
Attribute node type
- TYPE_CDATA
-
CDATA node type
- TYPE_COMMENT
-
Comment node type
- TYPE_DOCUMENT
-
Document node type
- TYPE_DOCUMENT_FRAGMENT
-
Document Fragment node type
- TYPE_DOCUMENT_TYPE
-
Document Type node type
- TYPE_ELEMENT
-
Element node type
- TYPE_END_ELEMENT
-
Element end node type
- TYPE_END_ENTITY
-
Entity end node type
- TYPE_ENTITY
-
Entity node type
- TYPE_ENTITY_REFERENCE
-
Entity Reference node type
- TYPE_NONE
- TYPE_NOTATION
-
Notation node type
- TYPE_PROCESSING_INSTRUCTION
-
PI node type
- TYPE_SIGNIFICANT_WHITESPACE
-
Significant Whitespace node type
- TYPE_TEXT
-
Text node type
- TYPE_WHITESPACE
-
Whitespace node type
- TYPE_XML_DECLARATION
-
XML Declaration node type
Attributes
The encoding for the document
A list of errors encountered while parsing
The XML source
Public Class Methods
Create a new reader that parses io
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)io_read_callback, (xmlInputCloseCallback)io_close_callback, (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 = Data_Wrap_Struct(klass, NULL, dealloc, reader); args[0] = rb_io; args[1] = rb_url; args[2] = encoding; rb_obj_call_init(rb_reader, 3, args); return rb_reader; }
Create a new reader that parses string
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 = Data_Wrap_Struct(klass, NULL, dealloc, reader); args[0] = rb_buffer; args[1] = rb_url; args[2] = encoding; rb_obj_call_init(rb_reader, 3, args); return rb_reader; }
Public Instance Methods
Get the value of attribute named name
static VALUE reader_attribute(VALUE self, VALUE name) { xmlTextReaderPtr reader; xmlChar *value ; VALUE rb_value; Data_Get_Struct(self, xmlTextReader, 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; }
Get the value of attribute at index
static VALUE attribute_at(VALUE self, VALUE index) { xmlTextReaderPtr reader; xmlChar *value; VALUE rb_value; Data_Get_Struct(self, xmlTextReader, 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; }
Get the number of attributes for the current node
static VALUE attribute_count(VALUE self) { xmlTextReaderPtr reader; int count; Data_Get_Struct(self, xmlTextReader, reader); count = xmlTextReaderAttributeCount(reader); if(count == -1) return Qnil; return INT2NUM((long)count); }
Get a list of attributes for the current node
# File lib/nokogiri/xml/reader.rb, line 97 def attribute_nodes nodes = attr_nodes nodes.each { |v| v.instance_variable_set(:@_r, self) } nodes end
Get a list of attributes for the current node.
# File lib/nokogiri/xml/reader.rb, line 89 def attributes Hash[attribute_nodes.map { |node| [node.name, node.to_s] }].merge(namespaces || {}) end
Does this node have attributes?
static VALUE attributes_eh(VALUE self) { xmlTextReaderPtr reader; int eh; Data_Get_Struct(self, xmlTextReader, reader); eh = has_attributes(reader); if(eh == 0) return Qfalse; if(eh == 1) return Qtrue; return Qnil; }
Get the xml:base of the node
static VALUE base_uri(VALUE self) { xmlTextReaderPtr reader; const char * base_uri; Data_Get_Struct(self, xmlTextReader, reader); base_uri = (const char *)xmlTextReaderBaseUri(reader); if (base_uri == NULL) return Qnil; return NOKOGIRI_STR_NEW2(base_uri); }
Was an attribute generated from the default value in the DTD or schema?
static VALUE default_eh(VALUE self) { xmlTextReaderPtr reader; int eh; Data_Get_Struct(self, xmlTextReader, reader); eh = xmlTextReaderIsDefault(reader); if(eh == 0) return Qfalse; if(eh == 1) return Qtrue; return Qnil; }
Get the depth of the node
static VALUE depth(VALUE self) { xmlTextReaderPtr reader; int depth; Data_Get_Struct(self, xmlTextReader, reader); depth = xmlTextReaderDepth(reader); if(depth == -1) return Qnil; return INT2NUM((long)depth); }
Move the cursor through the document yielding the cursor to the block
# File lib/nokogiri/xml/reader.rb, line 105 def each while cursor = self.read yield cursor end end
Returns true if the current node is empty, otherwise false.
static VALUE empty_element_p(VALUE self) { xmlTextReaderPtr reader; Data_Get_Struct(self, xmlTextReader, reader); if(xmlTextReaderIsEmptyElement(reader)) return Qtrue; return Qfalse; }
Read the contents of the current node, including child nodes and markup. Returns a utf-8 encoded string.
static VALUE inner_xml(VALUE self) { xmlTextReaderPtr reader; xmlChar* value; VALUE str; Data_Get_Struct(self, xmlTextReader, reader); value = xmlTextReaderReadInnerXml(reader); str = Qnil; if(value) { str = NOKOGIRI_STR_NEW2((char*)value); xmlFree(value); } return str; }
Get the xml:lang scope within which the node resides.
static VALUE lang(VALUE self) { xmlTextReaderPtr reader; const char *lang; Data_Get_Struct(self, xmlTextReader, reader); lang = (const char *)xmlTextReaderConstXmlLang(reader); if(lang == NULL) return Qnil; return NOKOGIRI_STR_NEW2(lang); }
Get the local name of the node
static VALUE local_name(VALUE self) { xmlTextReaderPtr reader; const char *name; Data_Get_Struct(self, xmlTextReader, reader); name = (const char *)xmlTextReaderConstLocalName(reader); if(name == NULL) return Qnil; return NOKOGIRI_STR_NEW2(name); }
Get the name of the node. Returns a utf-8 encoded string.
static VALUE name(VALUE self) { xmlTextReaderPtr reader; const char *name; Data_Get_Struct(self, xmlTextReader, reader); name = (const char *)xmlTextReaderConstName(reader); if(name == NULL) return Qnil; return NOKOGIRI_STR_NEW2(name); }
Get the URI defining the namespace associated with the node
static VALUE namespace_uri(VALUE self) { xmlTextReaderPtr reader; const char *uri; Data_Get_Struct(self, xmlTextReader, reader); uri = (const char *)xmlTextReaderConstNamespaceUri(reader); if(uri == NULL) return Qnil; return NOKOGIRI_STR_NEW2(uri); }
Get a hash of namespaces for this Node
static VALUE namespaces(VALUE self) { xmlTextReaderPtr reader; xmlNodePtr ptr; VALUE attr ; Data_Get_Struct(self, xmlTextReader, reader); attr = rb_hash_new() ; if (! has_attributes(reader)) return attr ; ptr = xmlTextReaderExpand(reader); if(ptr == NULL) return Qnil; Nokogiri_xml_node_namespaces(ptr, attr); return attr ; }
Get the type of readers current node
static VALUE node_type(VALUE self) { xmlTextReaderPtr reader; Data_Get_Struct(self, xmlTextReader, reader); return INT2NUM((long)xmlTextReaderNodeType(reader)); }
Read the current node and its contents, including child nodes and markup. Returns a utf-8 encoded string.
static VALUE outer_xml(VALUE self) { xmlTextReaderPtr reader; xmlChar *value; VALUE str = Qnil; Data_Get_Struct(self, xmlTextReader, reader); value = xmlTextReaderReadOuterXml(reader); if(value) { str = NOKOGIRI_STR_NEW2((char*)value); xmlFree(value); } return str; }
Get the shorthand reference to the namespace associated with the node.
static VALUE prefix(VALUE self) { xmlTextReaderPtr reader; const char *prefix; Data_Get_Struct(self, xmlTextReader, reader); prefix = (const char *)xmlTextReaderConstPrefix(reader); if(prefix == NULL) return Qnil; return NOKOGIRI_STR_NEW2(prefix); }
Move the Reader forward through the XML document.
static VALUE read_more(VALUE self) { xmlTextReaderPtr reader; xmlErrorPtr error; VALUE error_list; int ret; Data_Get_Struct(self, xmlTextReader, reader); error_list = rb_funcall(self, rb_intern("errors"), 0); xmlSetStructuredErrorFunc((void *)error_list, Nokogiri_error_array_pusher); ret = xmlTextReaderRead(reader); xmlSetStructuredErrorFunc(NULL, NULL); if(ret == 1) return self; if(ret == 0) return Qnil; error = xmlGetLastError(); if(error) rb_exc_raise(Nokogiri_wrap_xml_syntax_error(error)); else rb_raise(rb_eRuntimeError, "Error pulling: %d", ret); return Qnil; }
Get the state of the reader
static VALUE state(VALUE self) { xmlTextReaderPtr reader; Data_Get_Struct(self, xmlTextReader, reader); return INT2NUM((long)xmlTextReaderReadState(reader)); }
Get the text value of the node if present. Returns a utf-8 encoded string.
static VALUE value(VALUE self) { xmlTextReaderPtr reader; const char *value; Data_Get_Struct(self, xmlTextReader, reader); value = (const char *)xmlTextReaderConstValue(reader); if(value == NULL) return Qnil; return NOKOGIRI_STR_NEW2(value); }
Does this node have a text value?
static VALUE value_eh(VALUE self) { xmlTextReaderPtr reader; int eh; Data_Get_Struct(self, xmlTextReader, reader); eh = xmlTextReaderHasValue(reader); if(eh == 0) return Qfalse; if(eh == 1) return Qtrue; return Qnil; }
Get the XML version of the document being read
static VALUE xml_version(VALUE self) { xmlTextReaderPtr reader; const char *version; Data_Get_Struct(self, xmlTextReader, reader); version = (const char *)xmlTextReaderConstXmlVersion(reader); if(version == NULL) return Qnil; return NOKOGIRI_STR_NEW2(version); }
© 2008–2016 Aaron Patterson, Mike Dalessio, Charles Nutter, Sergio Arbeo
Patrick Mahoney, Yoko Harada, Akinori Musha, John Shahid
Licensed under the MIT License.