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Class: LibXML::XML::Attributes

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, Enumerable
Inherits: Object
Defined in: ext/libxml/ruby_xml_attributes.c,
ext/libxml/ruby_xml_attributes.c,
lib/libxml/attributes.rb

Overview

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'

Instance Method Summary

Instance Method Details

#[]("name") ⇒ String

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'
[ GitHub ] 

  


# File 'ext/libxml/ruby_xml_attributes.c', line 141



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);
}


  








  

    #[]=(name, value)  
  



  

    

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'


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_attributes.c', line 163



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  ⇒ XML::Attr   



  

    

Iterates over each attribute.



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


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_attributes.c', line 190



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   



  

    

Returns the first attribute.



doc.root.attributes.first


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_attributes.c', line 246



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})   



  

    

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 AttrDecl is returned.



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



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


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_attributes.c', line 76



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})   



  

    

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 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')


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_attributes.c', line 109



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   



  

    

Returns the number of attributes.



doc.root.attributes.length


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_attributes.c', line 220



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   



  

    

Return the node that owns this attributes list.



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


  



  [ GitHub ]


  

  


# File 'ext/libxml/ruby_xml_attributes.c', line 56



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


  








  

    #to_h  
  

  [ GitHub ]


  

  


# File 'lib/libxml/attributes.rb', line 6



def to_h
  inject({}) do |hash, attr|
    hash[attr.name] = attr.value
    hash
  end
end