Class: REXML::Attributes
Overview
A class that defines the set of Attributes of an Element and provides operations for accessing elements in that set.
Instance Method Summary collapse
-
#[](name) ⇒ Object
Fetches an attribute value.
-
#[]=(name, value) ⇒ Object
Sets an attribute, overwriting any existing attribute value by the same name.
-
#add(attribute) ⇒ Object
(also: #<<)
Adds an attribute, overriding any existing attribute by the same name.
-
#delete(attribute) ⇒ Object
- Removes an attribute attribute
-
either a String, which is the name of the attribute to remove -- namespaces are significant here -- or the attribute to remove.
-
#delete_all(name) ⇒ Object
Deletes all attributes matching a name.
-
#each ⇒ Object
Itterates over each attribute of an Element, yielding the expanded name and value as a pair of Strings.
-
#each_attribute ⇒ Object
Itterates over the attributes of an Element.
-
#get_attribute(name) ⇒ Object
- Fetches an attribute name
-
the name by which to search for the attribute.
-
#get_attribute_ns(namespace, name) ⇒ Object
The
get_attribute_ns
method retrieves a method by its namespace and name. -
#initialize(element) ⇒ Attributes
constructor
- Constructor element
-
the Element of which this is an Attribute.
-
#length ⇒ Object
(also: #size)
Returns the number of attributes the owning Element contains.
- #namespaces ⇒ Object
-
#prefixes ⇒ Object
Returns an array of Strings containing all of the prefixes declared by this set of # attributes.
- #to_a ⇒ Object
Constructor Details
#initialize(element) ⇒ Attributes
Constructor
- element
-
the Element of which this is an Attribute
957 958 959 |
# File 'lib/rexml/element.rb', line 957 def initialize element @element = element end |
Instance Method Details
#[](name) ⇒ Object
Fetches an attribute value. If you want to get the Attribute itself, use get_attribute()
- name
-
an XPath attribute name. Namespaces are relevant here.
- Returns
-
the String value of the matching attribute, or
nil
if no matching attribute was found. This is the unnormalized value (with entities expanded).
doc = Document.new "<a foo:att='1' bar:att='2' att='<'/>"
doc.root.attributes['att'] #-> '<'
doc.root.attributes['bar:att'] #-> '2'
972 973 974 975 976 |
# File 'lib/rexml/element.rb', line 972 def [](name) attr = get_attribute(name) return attr.value unless attr.nil? return nil end |
#[]=(name, value) ⇒ Object
Sets an attribute, overwriting any existing attribute value by the same name. Namespace is significant.
- name
-
the name of the attribute
- value
-
(optional) If supplied, the value of the attribute. If nil, any existing matching attribute is deleted.
- Returns
-
Owning element
doc = Document.new "<a x:foo='1' foo='3'/>"
doc.root.attributes['y:foo'] = '2'
doc.root.attributes['foo'] = '4'
doc.root.attributes['x:foo'] = nil
1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 |
# File 'lib/rexml/element.rb', line 1074 def []=( name, value ) if value.nil? # Delete the named attribute attr = get_attribute(name) delete attr return end element_document = @element.document unless value.kind_of? Attribute if @element.document and @element.document.doctype value = Text::normalize( value, @element.document.doctype ) else value = Text::normalize( value, nil ) end value = Attribute.new(name, value) end value.element = @element old_attr = fetch(value.name, nil) if old_attr.nil? store(value.name, value) elsif old_attr.kind_of? Hash old_attr[value.prefix] = value elsif old_attr.prefix != value.prefix # Check for conflicting namespaces raise ParseException.new( "Namespace conflict in adding attribute \"#{value.name}\": "+ "Prefix \"#{old_attr.prefix}\" = "+ "\"#{@element.namespace(old_attr.prefix)}\" and prefix "+ "\"#{value.prefix}\" = \"#{@element.namespace(value.prefix)}\"") if value.prefix != "xmlns" and old_attr.prefix != "xmlns" and @element.namespace( old_attr.prefix ) == @element.namespace( value.prefix ) store value.name, { old_attr.prefix => old_attr, value.prefix => value } else store value.name, value end return @element end |
#add(attribute) ⇒ Object Also known as: <<
Adds an attribute, overriding any existing attribute by the same name. Namespaces are significant.
- attribute
-
An Attribute
1193 1194 1195 |
# File 'lib/rexml/element.rb', line 1193 def add( attribute ) self[attribute.name] = attribute end |
#delete(attribute) ⇒ Object
Removes an attribute
- attribute
-
either a String, which is the name of the attribute to remove -- namespaces are significant here -- or the attribute to remove.
- Returns
-
the owning element
doc = Document.new "<a y:foo='0' x:foo='1' foo='3' z:foo='4'/>"
doc.root.attributes.delete 'foo' #-> <a y:foo='0' x:foo='1' z:foo='4'/>"
doc.root.attributes.delete 'x:foo' #-> <a y:foo='0' z:foo='4'/>"
attr = doc.root.attributes.get_attribute('y:foo')
doc.root.attributes.delete attr #-> <a z:foo='4'/>"
1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 |
# File 'lib/rexml/element.rb', line 1161 def delete( attribute ) name = nil prefix = nil if attribute.kind_of? Attribute name = attribute.name prefix = attribute.prefix else attribute =~ Namespace::NAMESPLIT prefix, name = $1, $2 prefix = '' unless prefix end old = fetch(name, nil) attr = nil if old.kind_of? Hash # the supplied attribute is one of many attr = old.delete(prefix) if old.size == 1 repl = nil old.each_value{|v| repl = v} store name, repl end elsif old.nil? return @element else # the supplied attribute is a top-level one attr = old res = super(name) end @element end |
#delete_all(name) ⇒ Object
Deletes all attributes matching a name. Namespaces are significant.
- name
-
A String; all attributes that match this path will be removed
- Returns
-
an Array of the Attributes that were removed
1203 1204 1205 1206 1207 1208 1209 1210 |
# File 'lib/rexml/element.rb', line 1203 def delete_all( name ) rv = [] each_attribute { |attribute| rv << attribute if attribute. == name } rv.each{ |attr| attr.remove } return rv end |
#each ⇒ Object
1014 1015 1016 1017 1018 |
# File 'lib/rexml/element.rb', line 1014 def each each_attribute do |attr| yield attr., attr.value end end |
#each_attribute ⇒ Object
999 1000 1001 1002 1003 1004 1005 1006 1007 |
# File 'lib/rexml/element.rb', line 999 def each_attribute # :yields: attribute each_value do |val| if val.kind_of? Attribute yield val else val.each_value { |atr| yield atr } end end end |
#get_attribute(name) ⇒ Object
Fetches an attribute
- name
-
the name by which to search for the attribute. Can be a
prefix:name
namespace name. - Returns
-
The first matching attribute, or nil if there was none. This
value is an Attribute node, not the String value of the attribute.
doc = Document.new '<a x:foo="1" foo="2" bar="3"/>'
doc.root.attributes.get_attribute("foo").value #-> "2"
doc.root.attributes.get_attribute("x:foo").value #-> "1"
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 |
# File 'lib/rexml/element.rb', line 1029 def get_attribute( name ) attr = fetch( name, nil ) if attr.nil? return nil if name.nil? # Look for prefix name =~ Namespace::NAMESPLIT prefix, n = $1, $2 if prefix attr = fetch( n, nil ) # check prefix if attr == nil elsif attr.kind_of? Attribute return attr if prefix == attr.prefix else attr = attr[ prefix ] return attr end end element_document = @element.document if element_document and element_document.doctype expn = @element. expn = element_document.doctype.name if expn.size == 0 attr_val = element_document.doctype.attribute_of(expn, name) return Attribute.new( name, attr_val ) if attr_val end return nil end if attr.kind_of? Hash attr = attr[ @element.prefix ] end return attr end |
#get_attribute_ns(namespace, name) ⇒ Object
The get_attribute_ns
method retrieves a method by its namespace and name. Thus it is possible to reliably identify an attribute even if an XML processor has changed the prefix.
Method contributed by Henrik Martensson
1217 1218 1219 1220 1221 1222 1223 1224 1225 |
# File 'lib/rexml/element.rb', line 1217 def get_attribute_ns(namespace, name) each_attribute() { |attribute| if name == attribute.name && namespace == attribute.namespace() return attribute end } nil end |
#length ⇒ Object Also known as: size
Returns the number of attributes the owning Element contains.
doc = Document "<a x='1' y='2' foo:x='3'/>"
doc.root.attributes.length #-> 3
985 986 987 988 989 |
# File 'lib/rexml/element.rb', line 985 def length c = 0 each_attribute { c+=1 } c end |
#namespaces ⇒ Object
1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 |
# File 'lib/rexml/element.rb', line 1135 def namespaces namespaces = {} each_attribute do |attribute| namespaces[attribute.name] = attribute.value if attribute.prefix == 'xmlns' or attribute.name == 'xmlns' end if @element.document and @element.document.doctype expn = @element. expn = @element.document.doctype.name if expn.size == 0 @element.document.doctype.attributes_of(expn).each { |attribute| namespaces[attribute.name] = attribute.value if attribute.prefix == 'xmlns' or attribute.name == 'xmlns' } end namespaces end |
#prefixes ⇒ Object
Returns an array of Strings containing all of the prefixes declared by this set of # attributes. The array does not include the default namespace declaration, if one exists.
doc = Document.new("<a xmlns='foo' xmlns:x='bar' xmlns:y='twee' "+
"z='glorp' p:k='gru'/>")
prefixes = doc.root.attributes.prefixes #-> ['x', 'y']
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 |
# File 'lib/rexml/element.rb', line 1119 def prefixes ns = [] each_attribute do |attribute| ns << attribute.name if attribute.prefix == 'xmlns' end if @element.document and @element.document.doctype expn = @element. expn = @element.document.doctype.name if expn.size == 0 @element.document.doctype.attributes_of(expn).each { |attribute| ns << attribute.name if attribute.prefix == 'xmlns' } end ns end |
#to_a ⇒ Object
978 979 980 |
# File 'lib/rexml/element.rb', line 978 def to_a values.flatten end |