Class: LibXML::XML::Attributes

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
ext/libxml/ruby_xml_attributes.c,
lib/libxml/attributes.rb,
ext/libxml/ruby_xml_attributes.c

Overview

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

Basic Usage:

require 'xml'

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 collapse

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'

Returns:

  • (String) 


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# File 'ext/libxml/ruby_xml_attributes.c', line 143

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") ⇒ Object

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'



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# File 'ext/libxml/ruby_xml_attributes.c', line 165

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}

Yields:

Returns:



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# File 'ext/libxml/ruby_xml_attributes.c', line 192

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

Returns:



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# File 'ext/libxml/ruby_xml_attributes.c', line 248

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 XML::AttrDecl is returned.

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

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

Returns:



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# File 'ext/libxml/ruby_xml_attributes.c', line 78

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 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')

Returns:



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# File 'ext/libxml/ruby_xml_attributes.c', line 111

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

Returns:

  • (Integer) 


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# File 'ext/libxml/ruby_xml_attributes.c', line 222

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

Returns:



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# File 'ext/libxml/ruby_xml_attributes.c', line 58

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

#to_h ⇒ Object 



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# File 'lib/libxml/attributes.rb', line 4

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