class LibXML::XML::Attributes

Provides access to an element’s attributes (XML::Attr).

Basic Usage:

require 'test_helper'

doc = XML::Document.new(<some_file>)
attributes = doc.root.attributes

attributes.each do |attribute|
  ..
end

attributes['foo'] = 'bar'
attribute = attributes.get_attribute['foo']
attribute.value == 'foo'

To access a namespaced attribute:

XLINK_URI = 'http://www.w3.org/1999/xlink'

attribute = attributes.get_attribute_ns(XLINK_URI, 'title')
attribute.value = 'My title'

Public Instance Methods

attributes["name"] → String click to toggle source

Fetches an attribute value. If you want to access the underlying Attribute itself use get_attribute.

name: The name of the attribute, not including any namespaces.

doc.root.attributes['att'] -> 'some value'

VALUE rxml_attributes_attribute_get(VALUE self, VALUE name)
{
  VALUE xattr = rxml_attributes_get_attribute(self, name);
  
  if (NIL_P(xattr))
    return Qnil;
  else
    return rxml_attr_value_get(xattr);
}

attributes["name"] = "value" click to toggle source

Sets an attribute value. If you want to get the Attribute itself, use get_attribute.

name: The name of the attribute, not including any namespaces. value: The new value of the namespace.

doc.root.attributes['att'] = 'some value'

VALUE rxml_attributes_attribute_set(VALUE self, VALUE name, VALUE value)
{
  VALUE xattr = rxml_attributes_get_attribute(self, name);
  if (NIL_P(xattr))
  {
    VALUE args[3];

    args[0] = rxml_attributes_node_get(self);
    args[1] = name;
    args[2] = value;

    return rb_class_new_instance(sizeof(args)/sizeof(VALUE), args, cXMLAttr);
  }
  else
  {
    return rxml_attr_value_set(xattr, value);
  }
}

each {block} → XML::Attr click to toggle source

Iterates over each attribute.

doc.root.attributes.each {|attribute| puts attribute.name}

static VALUE rxml_attributes_each(VALUE self)
{
  xmlNodePtr xnode;
  xmlAttrPtr xattr;
  Data_Get_Struct(self, xmlNode, xnode);

  xattr = xnode->properties;

  while (xattr)
  {
    /* Get the next attribute while we still can - the user
       may remove the yielded attribute. */
    xmlAttrPtr next = xattr->next;

    VALUE attr = rxml_attr_wrap(xattr);
    rb_yield(attr);
    xattr = next;
  }

  return self;
}

first → XML::Attr click to toggle source

Returns the first attribute.

doc.root.attributes.first

static VALUE rxml_attributes_first(VALUE self)
{
  xmlNodePtr xnode;
  Data_Get_Struct(self, xmlNode, xnode);

  if (xnode->type == XML_ELEMENT_NODE)
  {
    xmlAttrPtr xattr = xnode->properties;

    if (xattr)
    {
      return rxml_attr_wrap(xattr);
    }
  }
  return Qnil;
}

get_attribute("name") → (XML::Attr | XML::AtrrDecl) click to toggle source

Returns the specified attribute. If the attribute does not exist but the document has an associated DTD that defines a default value for the attribute, then a XML::AttrDecl is returned.

name: The name of the attribute, not including a namespace.

doc.root.attributes.get_attribute("foo")

static VALUE rxml_attributes_get_attribute(VALUE self, VALUE name)
{
  xmlNodePtr xnode;
  xmlAttrPtr xattr;

  name = rb_obj_as_string(name);

  Data_Get_Struct(self, xmlNode, xnode);

  xattr = xmlHasProp(xnode, (xmlChar*) StringValuePtr(name));

  if (!xattr)
    return Qnil;
  else if (xattr->type == XML_ATTRIBUTE_DECL)
    return rxml_attr_decl_wrap((xmlAttributePtr)xattr);
  else
    return rxml_attr_wrap(xattr);
}

get_attribute_ns("namespace", "name") → (XML::Attr | XML::AtrrDecl) click to toggle source

Returns the specified attribute. If the attribute does not exist but the document has an associated DTD that defines a default value for the attribute, then a XML::AttrDecl is returned.

namespace: The URI of the attribute’s namespace. name: The name of the attribute, not including a namespace.

doc.root.attributes.get_attribute_ns('http://www.w3.org/1999/xlink', 'href')

static VALUE rxml_attributes_get_attribute_ns(VALUE self, VALUE namespace,
    VALUE name)
{
  xmlNodePtr xnode;
  xmlAttrPtr xattr;

  name = rb_obj_as_string(name);

  Data_Get_Struct(self, xmlNode, xnode);

  xattr = xmlHasNsProp(xnode, (xmlChar*) StringValuePtr(name),
                      (xmlChar*) StringValuePtr(namespace));

  if (!xattr)
    return Qnil;
  else if (xattr->type == XML_ATTRIBUTE_DECL)
    return rxml_attr_decl_wrap((xmlAttributePtr)xattr);
  else
    return rxml_attr_wrap(xattr);
}

length → Integer click to toggle source

Returns the number of attributes.

doc.root.attributes.length

static VALUE rxml_attributes_length(VALUE self)
{
  int length = 0;
  xmlNodePtr xnode;
  xmlAttrPtr xattr;
  Data_Get_Struct(self, xmlNode, xnode);

  xattr = xnode->properties;

  while (xattr)
  {
    length++;
    xattr = xattr->next;
  }
  
  return INT2NUM(length);
}

node → XML::Node click to toggle source

Return the node that owns this attributes list.

doc.root.attributes.node == doc.root

VALUE rxml_attributes_node_get(VALUE self)
{
  xmlNodePtr xnode;
  Data_Get_Struct(self, xmlNode, xnode);
  return rxml_node_wrap(xnode);
}

to_h() click to toggle source

   # File lib/libxml/attributes.rb
 6 def to_h
 7   inject({}) do |hash, attr|
 8     hash[attr.name] = attr.value
 9     hash
10   end
11 end