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.

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

Note that Nokogiri::XML::Reader#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.

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

4
TYPE_ENTITY_REFERENCE =

Entity Reference node type

5
TYPE_ENTITY =

Entity node type

6
TYPE_PROCESSING_INSTRUCTION =

PI node type

7
TYPE_COMMENT =

Comment node type

8
TYPE_DOCUMENT =

Document node type

9
TYPE_DOCUMENT_TYPE =

Document Type node type

10
TYPE_DOCUMENT_FRAGMENT =

Document Fragment node type

11
TYPE_NOTATION =

Notation node type

12
TYPE_WHITESPACE =

Whitespace node type

13
TYPE_SIGNIFICANT_WHITESPACE =

Significant Whitespace node type

14
TYPE_END_ELEMENT =

Element end node type

15
TYPE_END_ENTITY =

Entity end node type

16
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



72
73
74
 
# File 'lib/nokogiri/xml/reader.rb', line 72

def errors
  @errors
end

#source ⇒ Object (readonly)

The XML source



75
76
77
 
# File 'lib/nokogiri/xml/reader.rb', line 75

def source
  @source
end

Class Method Details

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

Create a new reader that parses io



602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
 
# File 'ext/nokogiri/xml_reader.c', line 602

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 = 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;
}

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

Create a new reader that parses string



557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
 
# File 'ext/nokogiri/xml_reader.c', line 557

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;
}

Instance Method Details

#attribute(name) ⇒ Object

Get the value of attribute named name



219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
 
# File 'ext/nokogiri/xml_reader.c', line 219

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;
}

#attribute_at(index) ⇒ Object

Get the value of attribute at index



190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
 
# File 'ext/nokogiri/xml_reader.c', line 190

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;
}

#attribute_count ⇒ Object

Get the number of attributes for the current node



245
246
247
248
249
250
251
252
253
254
255
256
 
# File 'ext/nokogiri/xml_reader.c', line 245

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);
}

#attribute_nodes ⇒ Object

:call-seq: attribute_nodes() → Array<Nokogiri::XML::Attr>

Get the attributes of the current node as an Array of Attr



155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
 
# File 'ext/nokogiri/xml_reader.c', line 155

static VALUE
rb_xml_reader_attribute_nodes(VALUE rb_reader)
{
  xmlTextReaderPtr c_reader;
  xmlNodePtr c_node;
  VALUE attr_nodes;
  int j;

  Data_Get_Struct(rb_reader, xmlTextReader, c_reader);

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

  c_node = xmlTextReaderExpand(c_reader);
  if (c_node == NULL) {
    return Qnil;
  }

  attr_nodes = noko_xml_node_attrs(c_node);

  /* ensure that the Reader won't be GCed as long as a node is referenced */
  for (j = 0 ; j < RARRAY_LEN(attr_nodes) ; j++) {
    rb_iv_set(rb_ary_entry(attr_nodes, j), "@reader", rb_reader);
  }

  return attr_nodes;
}

#attributes ⇒ Object

Get the attributes of the current node as a Hash

Returns

(Hash<String, String>) Attribute names and values



89
90
91
92
93
94
95
96
 
# File 'lib/nokogiri/xml/reader.rb', line 89

def attributes
  attrs_hash = attribute_nodes.each_with_object({}) do |node, hash|
    hash[node.name] = node.to_s
  end
  ns = namespaces
  attrs_hash.merge!(ns) if ns
  attrs_hash
end

#attributes? ⇒ Boolean

Does this node have attributes?

Returns:

  • (Boolean) 


107
108
109
110
111
112
113
114
115
116
117
118
119
 
# File 'ext/nokogiri/xml_reader.c', line 107

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;
}

#base_uri ⇒ Object

base_uri

Get the xml:base of the node



416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
 
# File 'ext/nokogiri/xml_reader.c', line 416

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

  Data_Get_Struct(rb_reader, xmlTextReader, 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) 


67
68
69
70
71
72
73
74
75
76
77
78
79
 
# File 'ext/nokogiri/xml_reader.c', line 67

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;
}

#depth ⇒ Object

Get the depth of the node



264
265
266
267
268
269
270
271
272
273
274
275
 
# File 'ext/nokogiri/xml_reader.c', line 264

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);
}

#each ⇒ Object

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



100
101
102
103
104
 
# File 'lib/nokogiri/xml/reader.rb', line 100

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) 


648
649
650
651
652
653
654
655
656
657
658
659
660
 
# File 'ext/nokogiri/xml_reader.c', line 648

static VALUE
empty_element_p(VALUE self)
{
  xmlTextReaderPtr reader;

  Data_Get_Struct(self, xmlTextReader, reader);

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

  return Qfalse;
}

#encoding ⇒ Object 



662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
 
# File 'ext/nokogiri/xml_reader.c', line 662

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

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

  Data_Get_Struct(rb_reader, xmlTextReader, c_reader);
  parser_encoding = (const char *)xmlTextReaderConstEncoding(c_reader);
  if (parser_encoding == NULL) { return Qnil; }
  return NOKOGIRI_STR_NEW2(parser_encoding);
}

#inner_xml ⇒ Object

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



506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
 
# File 'ext/nokogiri/xml_reader.c', line 506

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;
}

#lang ⇒ Object

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



302
303
304
305
306
307
308
309
310
311
312
313
 
# File 'ext/nokogiri/xml_reader.c', line 302

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);
}

#local_name ⇒ Object

Get the local name of the node



378
379
380
381
382
383
384
385
386
387
388
389
 
# File 'ext/nokogiri/xml_reader.c', line 378

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);
}

#name ⇒ Object

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



397
398
399
400
401
402
403
404
405
406
407
408
 
# File 'ext/nokogiri/xml_reader.c', line 397

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);
}

#namespace_uri ⇒ Object

Get the URI defining the namespace associated with the node



359
360
361
362
363
364
365
366
367
368
369
370
 
# File 'ext/nokogiri/xml_reader.c', line 359

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);
}

#namespaces ⇒ Object

Get a hash of namespaces for this Node



127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
 
# File 'ext/nokogiri/xml_reader.c', line 127

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 ;
}

#node_type ⇒ Object

Get the type of readers current node



456
457
458
459
460
461
462
 
# File 'ext/nokogiri/xml_reader.c', line 456

static VALUE
node_type(VALUE self)
{
  xmlTextReaderPtr reader;
  Data_Get_Struct(self, xmlTextReader, reader);
  return INT2NUM((long)xmlTextReaderNodeType(reader));
}

#outer_xml ⇒ Object

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



533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
 
# File 'ext/nokogiri/xml_reader.c', line 533

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;
}

#prefix ⇒ Object

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



340
341
342
343
344
345
346
347
348
349
350
351
 
# File 'ext/nokogiri/xml_reader.c', line 340

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);
}

#read ⇒ Object

Move the Reader forward through the XML document.



470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
 
# File 'ext/nokogiri/xml_reader.c', line 470

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;
}

#state ⇒ Object

Get the state of the reader



442
443
444
445
446
447
448
 
# File 'ext/nokogiri/xml_reader.c', line 442

static VALUE
state(VALUE self)
{
  xmlTextReaderPtr reader;
  Data_Get_Struct(self, xmlTextReader, reader);
  return INT2NUM((long)xmlTextReaderReadState(reader));
}

#value ⇒ Object

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



321
322
323
324
325
326
327
328
329
330
331
332
 
# File 'ext/nokogiri/xml_reader.c', line 321

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);
}

#value? ⇒ Boolean

Does this node have a text value?

Returns:

  • (Boolean) 


87
88
89
90
91
92
93
94
95
96
97
98
99
 
# File 'ext/nokogiri/xml_reader.c', line 87

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;
}

#xml_version ⇒ Object

Get the XML version of the document being read



283
284
285
286
287
288
289
290
291
292
293
294
 
# File 'ext/nokogiri/xml_reader.c', line 283

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);
}