class LibXML::XML::Attr

Provides access to an attribute defined on an element.

Basic Usage:

require 'test_helper'

doc = XML::Document.new(<some_file>)
attribute = doc.root.attributes.get_attribute_ns('http://www.w3.org/1999/xlink', 'href')
attribute.name == 'href'
attribute.value == 'http://www.mydocument.com'
attribute.remove!

Public Class Methods

initialize(node, "name", "value")

Source

static VALUE rxml_attr_initialize(int argc, VALUE *argv, VALUE self)
{
  VALUE node = argv[0];
  VALUE name = argv[1];
  VALUE value = argv[2];
  VALUE ns = (argc == 4 ? argv[3] : Qnil);

  xmlNodePtr xnode;
  xmlAttrPtr xattr;

  if (argc < 3 || argc > 4)
    rb_raise(rb_eArgError, "Wrong number of arguments (3 or 4)");

  Check_Type(name, T_STRING);
  Check_Type(value, T_STRING);

  TypedData_Get_Struct(node, xmlNode, &rxml_node_data_type, xnode);

  if (xnode->type != XML_ELEMENT_NODE)
    rb_raise(rb_eArgError, "Attributes can only be created on element nodes.");

  if (NIL_P(ns))
  {
    xattr = xmlNewProp(xnode, (xmlChar*)StringValuePtr(name), (xmlChar*)StringValuePtr(value));
  }
  else
  {
    xmlNsPtr xns;
    TypedData_Get_Struct(ns, xmlNs, &rxml_namespace_type, xns);
    xattr = xmlNewNsProp(xnode, xns, (xmlChar*)StringValuePtr(name), (xmlChar*)StringValuePtr(value));
  }

  if (!xattr)
    rb_raise(rb_eRuntimeError, "Could not create attribute.");

  RTYPEDDATA_DATA( self) = xattr;
  return self;
}

Creates a new attribute for the node.

node: The XML::Node that will contain the attribute name: The name of the attribute value: The value of the attribute

attr = XML::Attr.new(doc.root, 'name', 'libxml')

Public Instance Methods

child → node

Source

static VALUE rxml_attr_child_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  if (xattr->children == NULL)
    return Qnil;
  else
    return rxml_node_wrap((xmlNodePtr) xattr->children);
}

Obtain this attribute’s child attribute(s).

child? → (true|false)

Source

   # File lib/libxml/attr.rb
13 def child?
14   not self.children.nil?
15 end

Returns whether this attribute has child attributes.

doc → XML::Document

Source

static VALUE rxml_attr_doc_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  if (xattr->doc == NULL)
    return Qnil;
  else
    return rxml_registry_lookup(xattr->doc);
}

Returns this attribute’s document.

doc.root.attributes.get_attribute('name').doc == doc

doc? → (true|false)

Source

   # File lib/libxml/attr.rb
22 def doc?
23   not self.doc.nil?
24 end

Determine whether this attribute is associated with an XML::Document.

each (&blk)

Alias for: each_sibling

each_attr (&blk)

Alias for: each_sibling

each_sibling (&blk)

Source

   # File lib/libxml/attr.rb
97 def each_sibling(&blk)
98   siblings(self,&blk)
99 end

Also aliased as: each_attr, each

last → node

Source

static VALUE rxml_attr_last_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  if (xattr->last == NULL)
    return Qnil;
  else
    return rxml_node_wrap(xattr->last);
}

Obtain the last attribute.

last? → (true|false)

Source

   # File lib/libxml/attr.rb
30 def last?
31   self.last.nil?
32 end

Determine whether this is the last attribute.

name → "name"

Source

static VALUE rxml_attr_name_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);

  if (xattr->name == NULL)
    return Qnil;
  else
    return rxml_new_cstr( xattr->name, NULL);
}

Obtain this attribute’s name.

namespacess → XML::Namespaces

Source

   # File lib/libxml/attr.rb
57 def namespaces
58   @namespaces ||= XML::Namespaces.new(self)
59 end

Returns this node’s XML::Namespaces object, which is used to access the namespaces associated with this node.

next → node

Source

static VALUE rxml_attr_next_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  if (xattr->next == NULL)
    return Qnil;
  else
    return rxml_attr_wrap(xattr->next);
}

Obtain the next attribute.

next? → (true|false)

Source

   # File lib/libxml/attr.rb
38 def next?
39   not self.next.nil?
40 end

Determine whether there is a next attribute.

node_type → num

Source

static VALUE rxml_attr_node_type(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  return INT2NUM(xattr->type);
}

Obtain this node’s type identifier.

node_type_name ()

Source

   # File lib/libxml/attr.rb
79 def node_type_name
80   if node_type == Node::ATTRIBUTE_NODE
81     'attribute'
82   else
83     raise(UnknownType, "Unknown node type: %n", node.node_type);
84   end
85 end

Returns this node’s type name

ns → namespace

Source

static VALUE rxml_attr_ns_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  if (xattr->ns == NULL)
    return Qnil;
  else
    return rxml_namespace_wrap(xattr->ns);
}

Obtain this attribute’s associated XML::NS, if any.

ns? → (true|false)

Source

   # File lib/libxml/attr.rb
47 def ns?
48   not self.ns.nil?
49 end

Determine whether this attribute has an associated namespace.

parent → node

Source

static VALUE rxml_attr_parent_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  if (xattr->parent == NULL)
    return Qnil;
  else
    return rxml_node_wrap(xattr->parent);
}

Obtain this attribute node’s parent.

parent? → (true|false)

Source

   # File lib/libxml/attr.rb
66 def parent?
67   not self.parent.nil?
68 end

Determine whether this attribute has a parent.

prev → node

Source

static VALUE rxml_attr_prev_get(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  if (xattr->prev == NULL)
    return Qnil;
  else
    return rxml_attr_wrap(xattr->prev);
}

Obtain the previous attribute.

prev? → (true|false)

Source

   # File lib/libxml/attr.rb
74 def prev?
75   not self.prev.nil?
76 end

Determine whether there is a previous attribute.

remove! → nil

Source

static VALUE rxml_attr_remove_ex(VALUE self)
{
  xmlAttrPtr xattr;
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  xmlRemoveProp(xattr);

  RTYPEDDATA_DATA(self) = NULL;

  return Qnil;
}

Removes this attribute from it’s parent. Note the attribute and its content is freed and can no longer be used. If you try to use it you will get a segmentation fault.

siblings (node, &blk)

Source

   # File lib/libxml/attr.rb
88 def siblings(node, &blk)
89   if n = node
90     loop do
91       blk.call(n)
92       break unless n = n.next
93     end
94   end
95 end

Iterates nodes and attributes

to_a ()

Source

    # File lib/libxml/attr.rb
111 def to_a
112   inject([]) do |ary,a| 
113     ary << [a.name, a.value]
114     ary
115   end
116 end

to_h ()

Source

    # File lib/libxml/attr.rb
104 def to_h
105   inject({}) do |h,a|
106     h[a.name] = a.value
107     h
108   end
109 end

to_s ()

Source

    # File lib/libxml/attr.rb
118 def to_s
119   "#{name} = #{value}"
120 end

value → "value"

Source

VALUE rxml_attr_value_get(VALUE self)
{
  xmlAttrPtr xattr;
  xmlChar *value;
  VALUE result = Qnil;

  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);
  value = xmlNodeGetContent((xmlNodePtr)xattr);

  if (value != NULL)
  {
    result = rxml_new_cstr( value, NULL);
    xmlFree(value);
  }
  return result;
}

Obtain the value of this attribute.

value = "value"

Source

VALUE rxml_attr_value_set(VALUE self, VALUE val)
{
  xmlAttrPtr xattr;

  Check_Type(val, T_STRING);
  TypedData_Get_Struct(self, xmlAttr, &rxml_attr_type, xattr);

  if (xattr->ns)
    xmlSetNsProp(xattr->parent, xattr->ns, xattr->name,
        (xmlChar*) StringValuePtr(val));
  else
    xmlSetProp(xattr->parent, xattr->name, (xmlChar*) StringValuePtr(val));

  return (self);
}

Sets the value of this attribute.