require "rexml/parent" require "rexml/namespace" require "rexml/attribute" require "rexml/cdata" require "rexml/xpath" require "rexml/parseexception" module REXML # An implementation note about namespaces: # As we parse, when we find namespaces we put them in a hash and assign # them a unique ID. We then convert the namespace prefix for the node # to the unique ID. This makes namespace lookup much faster for the # cost of extra memory use. We save the namespace prefix for the # context node and convert it back when we write it. @@namespaces = {} # Represents a tagged XML element. Elements are characterized by # having children, attributes, and names, and can themselves be # children. class Element < Parent include Namespace UNDEFINED = "UNDEFINED"; # The default name # Mechanisms for accessing attributes and child elements of this # element. attr_reader :attributes, :elements # The context holds information about the processing environment, such as # whitespace handling. attr_accessor :context # Constructor # arg:: # if not supplied, will be set to the default value. # If a String, the name of this object will be set to the argument. # If an Element, the object will be shallowly cloned; name, # attributes, and namespaces will be copied. Children will +not+ be # copied. # parent:: # if supplied, must be a Parent, and will be used as # the parent of this object. # context:: # If supplied, must be a hash containing context items. Context items # include: # * <tt>:respect_whitespace</tt> the value of this is :+all+ or an array of # strings being the names of the elements to respect # whitespace for. Defaults to :+all+. # * <tt>:compress_whitespace</tt> the value can be :+all+ or an array of # strings being the names of the elements to ignore whitespace on. # Overrides :+respect_whitespace+. # * <tt>:ignore_whitespace_nodes</tt> the value can be :+all+ or an array # of strings being the names of the elements in which to ignore # whitespace-only nodes. If this is set, Text nodes which contain only # whitespace will not be added to the document tree. # * <tt>:raw</tt> can be :+all+, or an array of strings being the names of # the elements to process in raw mode. In raw mode, special # characters in text is not converted to or from entities. def initialize( arg = UNDEFINED, parent=nil, context=nil ) super(parent) @elements = Elements.new(self) @attributes = Attributes.new(self) @context = context if arg.kind_of? String self.name = arg elsif arg.kind_of? Element self.name = arg.expanded_name arg.attributes.each_attribute{ |attribute| @attributes << Attribute.new( attribute ) } @context = arg.context end end def inspect rv = "<#@expanded_name" @attributes.each_attribute do |attr| rv << " " attr.write( rv, 0 ) end if children.size > 0 rv << "> ... </>" else rv << "/>" end end # Creates a shallow copy of self. # d = Document.new "<a><b/><b/><c><d/></c></a>" # new_a = d.root.clone # puts new_a # => "<a/>" def clone self.class.new self end # Evaluates to the root node of the document that this element # belongs to. If this element doesn't belong to a document, but does # belong to another Element, the parent's root will be returned, until the # earliest ancestor is found. # # Note that this is not the same as the document element. # In the following example, <a> is the document element, and the root # node is the parent node of the document element. You may ask yourself # why the root node is useful: consider the doctype and XML declaration, # and any processing instructions before the document element... they # are children of the root node, or siblings of the document element. # The only time this isn't true is when an Element is created that is # not part of any Document. In this case, the ancestor that has no # parent acts as the root node. # d = Document.new '<a><b><c/></b></a>' # a = d[1] ; c = a[1][1] # d.root_node == d # TRUE # a.root_node # namely, d # c.root_node # again, d def root_node parent.nil? ? self : parent.root_node end def root return elements[1] if self.kind_of? Document return self if parent.kind_of? Document or parent.nil? return parent.root end # Evaluates to the document to which this element belongs, or nil if this # element doesn't belong to a document. def document rt = root rt.parent if rt end # Evaluates to +true+ if whitespace is respected for this element. This # is the case if: # 1. Neither :+respect_whitespace+ nor :+compress_whitespace+ has any value # 2. The context has :+respect_whitespace+ set to :+all+ or # an array containing the name of this element, and # :+compress_whitespace+ isn't set to :+all+ or an array containing the # name of this element. # The evaluation is tested against +expanded_name+, and so is namespace # sensitive. def whitespace @whitespace = nil if @context if @context[:respect_whitespace] @whitespace = (@context[:respect_whitespace] == :all or @context[:respect_whitespace].include? expanded_name) end @whitespace = false if (@context[:compress_whitespace] and (@context[:compress_whitespace] == :all or @context[:compress_whitespace].include? expanded_name) ) end @whitespace = true unless @whitespace == false @whitespace end def ignore_whitespace_nodes @ignore_whitespace_nodes = false if @context if @context[:ignore_whitespace_nodes] @ignore_whitespace_nodes = (@context[:ignore_whitespace_nodes] == :all or @context[:ignore_whitespace_nodes].include? expanded_name) end end end # Evaluates to +true+ if raw mode is set for this element. This # is the case if the context has :+raw+ set to :+all+ or # an array containing the name of this element. # # The evaluation is tested against +expanded_name+, and so is namespace # sensitive. def raw @raw = (@context and @context[:raw] and (@context[:raw] == :all or @context[:raw].include? expanded_name)) @raw end #once :whitespace, :raw, :ignore_whitespace_nodes ################################################# # Namespaces # ################################################# # Evaluates to an +Array+ containing the prefixes (names) of all defined # namespaces at this context node. # doc = Document.new("<a xmlns:x='1' xmlns:y='2'><b/><c xmlns:z='3'/></a>") # doc.elements['//b'].prefixes # -> ['x', 'y'] def prefixes prefixes = [] prefixes = parent.prefixes if parent prefixes |= attributes.prefixes return prefixes end def namespaces namespaces = {} namespaces = parent.namespaces if parent namespaces = namespaces.merge( attributes.namespaces ) return namespaces end # Evalutas to the URI for a prefix, or the empty string if no such # namespace is declared for this element. Evaluates recursively for # ancestors. Returns the default namespace, if there is one. # prefix:: # the prefix to search for. If not supplied, returns the default # namespace if one exists # Returns:: # the namespace URI as a String, or nil if no such namespace # exists. If the namespace is undefined, returns an empty string # doc = Document.new("<a xmlns='1' xmlns:y='2'><b/><c xmlns:z='3'/></a>") # b = doc.elements['//b'] # b.namespace # -> '1' # b.namespace("y") # -> '2' def namespace(prefix=nil) if prefix.nil? prefix = prefix() end if prefix == '' prefix = "xmlns" else prefix = "xmlns:#{prefix}" unless prefix[0,5] == 'xmlns' end ns = attributes[ prefix ] ns = parent.namespace(prefix) if ns.nil? and parent ns = '' if ns.nil? and prefix == 'xmlns' return ns end # Adds a namespace to this element. # prefix:: # the prefix string, or the namespace URI if +uri+ is not # supplied # uri:: # the namespace URI. May be nil, in which +prefix+ is used as # the URI # Evaluates to: this Element # a = Element.new("a") # a.add_namespace("xmlns:foo", "bar" ) # a.add_namespace("foo", "bar") # shorthand for previous line # a.add_namespace("twiddle") # puts a #-> <a xmlns:foo='bar' xmlns='twiddle'/> def add_namespace( prefix, uri=nil ) unless uri @attributes["xmlns"] = prefix else prefix = "xmlns:#{prefix}" unless prefix =~ /^xmlns:/ @attributes[ prefix ] = uri end self end # Removes a namespace from this node. This only works if the namespace is # actually declared in this node. If no argument is passed, deletes the # default namespace. # # Evaluates to: this element # doc = Document.new "<a xmlns:foo='bar' xmlns='twiddle'/>" # doc.root.delete_namespace # puts doc # -> <a xmlns:foo='bar'/> # doc.root.delete_namespace 'foo' # puts doc # -> <a/> def delete_namespace namespace="xmlns" namespace = "xmlns:#{namespace}" unless namespace == 'xmlns' attribute = attributes.get_attribute(namespace) attribute.remove unless attribute.nil? self end ################################################# # Elements # ################################################# # Adds a child to this element, optionally setting attributes in # the element. # element:: # optional. If Element, the element is added. # Otherwise, a new Element is constructed with the argument (see # Element.initialize). # attrs:: # If supplied, must be a Hash containing String name,value # pairs, which will be used to set the attributes of the new Element. # Returns:: the Element that was added # el = doc.add_element 'my-tag' # el = doc.add_element 'my-tag', {'attr1'=>'val1', 'attr2'=>'val2'} # el = Element.new 'my-tag' # doc.add_element el def add_element element, attrs=nil raise "First argument must be either an element name, or an Element object" if element.nil? el = @elements.add(element) attrs.each do |key, value| el.attributes[key]=Attribute.new(key,value,self) end if attrs.kind_of? Hash el end # Deletes a child element. # element:: # Must be an +Element+, +String+, or +Integer+. If Element, # the element is removed. If String, the element is found (via XPath) # and removed. <em>This means that any parent can remove any # descendant.<em> If Integer, the Element indexed by that number will be # removed. # Returns:: the element that was removed. # doc.delete_element "/a/b/c[@id='4']" # doc.delete_element doc.elements["//k"] # doc.delete_element 1 def delete_element element @elements.delete element end # Evaluates to +true+ if this element has at least one child Element # doc = Document.new "<a><b/><c>Text</c></a>" # doc.root.has_elements # -> true # doc.elements["/a/b"].has_elements # -> false # doc.elements["/a/c"].has_elements # -> false def has_elements? !@elements.empty? end # Iterates through the child elements, yielding for each Element that # has a particular attribute set. # key:: # the name of the attribute to search for # value:: # the value of the attribute # max:: # (optional) causes this method to return after yielding # for this number of matching children # name:: # (optional) if supplied, this is an XPath that filters # the children to check. # # doc = Document.new "<a><b @id='1'/><c @id='2'/><d @id='1'/><e/></a>" # # Yields b, c, d # doc.root.each_element_with_attribute( 'id' ) {|e| p e} # # Yields b, d # doc.root.each_element_with_attribute( 'id', '1' ) {|e| p e} # # Yields b # doc.root.each_element_with_attribute( 'id', '1', 1 ) {|e| p e} # # Yields d # doc.root.each_element_with_attribute( 'id', '1', 0, 'd' ) {|e| p e} def each_element_with_attribute( key, value=nil, max=0, name=nil, &block ) # :yields: Element each_with_something( proc {|child| if value.nil? child.attributes[key] != nil else child.attributes[key]==value end }, max, name, &block ) end # Iterates through the children, yielding for each Element that # has a particular text set. # text:: # the text to search for. If nil, or not supplied, will iterate # over all +Element+ children that contain at least one +Text+ node. # max:: # (optional) causes this method to return after yielding # for this number of matching children # name:: # (optional) if supplied, this is an XPath that filters # the children to check. # # doc = Document.new '<a><b>b</b><c>b</c><d>d</d><e/></a>' # # Yields b, c, d # doc.each_element_with_text {|e|p e} # # Yields b, c # doc.each_element_with_text('b'){|e|p e} # # Yields b # doc.each_element_with_text('b', 1){|e|p e} # # Yields d # doc.each_element_with_text(nil, 0, 'd'){|e|p e} def each_element_with_text( text=nil, max=0, name=nil, &block ) # :yields: Element each_with_something( proc {|child| if text.nil? child.has_text? else child.text == text end }, max, name, &block ) end # Synonym for Element.elements.each def each_element( xpath=nil, &block ) # :yields: Element @elements.each( xpath, &block ) end # Synonym for Element.to_a # This is a little slower than calling elements.each directly. # xpath:: any XPath by which to search for elements in the tree # Returns:: an array of Elements that match the supplied path def get_elements( xpath ) @elements.to_a( xpath ) end # Returns the next sibling that is an element, or nil if there is # no Element sibling after this one # doc = Document.new '<a><b/>text<c/></a>' # doc.root.elements['b'].next_element #-> <c/> # doc.root.elements['c'].next_element #-> nil def next_element element = next_sibling element = element.next_sibling until element.nil? or element.kind_of? Element return element end # Returns the previous sibling that is an element, or nil if there is # no Element sibling prior to this one # doc = Document.new '<a><b/>text<c/></a>' # doc.root.elements['c'].previous_element #-> <b/> # doc.root.elements['b'].previous_element #-> nil def previous_element element = previous_sibling element = element.previous_sibling until element.nil? or element.kind_of? Element return element end ################################################# # Text # ################################################# # Evaluates to +true+ if this element has at least one Text child def has_text? not text().nil? end # A convenience method which returns the String value of the _first_ # child text element, if one exists, and +nil+ otherwise. # # <em>Note that an element may have multiple Text elements, perhaps # separated by other children</em>. Be aware that this method only returns # the first Text node. # # This method returns the +value+ of the first text child node, which # ignores the +raw+ setting, so always returns normalized text. See # the Text::value documentation. # # doc = Document.new "<p>some text <b>this is bold!</b> more text</p>" # # The element 'p' has two text elements, "some text " and " more text". # doc.root.text #-> "some text " def text( path = nil ) rv = get_text(path) return rv.value unless rv.nil? nil end # Returns the first child Text node, if any, or +nil+ otherwise. # This method returns the actual +Text+ node, rather than the String content. # doc = Document.new "<p>some text <b>this is bold!</b> more text</p>" # # The element 'p' has two text elements, "some text " and " more text". # doc.root.get_text.value #-> "some text " def get_text path = nil rv = nil if path element = @elements[ path ] rv = element.get_text unless element.nil? else rv = @children.find { |node| node.kind_of? Text } end return rv end # Sets the first Text child of this object. See text() for a # discussion about Text children. # # If a Text child already exists, the child is replaced by this # content. This means that Text content can be deleted by calling # this method with a nil argument. In this case, the next Text # child becomes the first Text child. In no case is the order of # any siblings disturbed. # text:: # If a String, a new Text child is created and added to # this Element as the first Text child. If Text, the text is set # as the first Child element. If nil, then any existing first Text # child is removed. # Returns:: this Element. # doc = Document.new '<a><b/></a>' # doc.root.text = 'Sean' #-> '<a><b/>Sean</a>' # doc.root.text = 'Elliott' #-> '<a><b/>Elliott</a>' # doc.root.add_element 'c' #-> '<a><b/>Elliott<c/></a>' # doc.root.text = 'Russell' #-> '<a><b/>Russell<c/></a>' # doc.root.text = nil #-> '<a><b/><c/></a>' def text=( text ) if text.kind_of? String text = Text.new( text, whitespace(), nil, raw() ) elsif text and !text.kind_of? Text text = Text.new( text.to_s, whitespace(), nil, raw() ) end old_text = get_text if text.nil? old_text.remove unless old_text.nil? else if old_text.nil? self << text else old_text.replace_with( text ) end end return self end # A helper method to add a Text child. Actual Text instances can # be added with regular Parent methods, such as add() and <<() # text:: # if a String, a new Text instance is created and added # to the parent. If Text, the object is added directly. # Returns:: this Element # e = Element.new('a') #-> <e/> # e.add_text 'foo' #-> <e>foo</e> # e.add_text Text.new(' bar') #-> <e>foo bar</e> # Note that at the end of this example, the branch has <b>3</b> nodes; the 'e' # element and <b>2</b> Text node children. def add_text( text ) if text.kind_of? String if @children[-1].kind_of? Text @children[-1] << text return end text = Text.new( text, whitespace(), nil, raw() ) end self << text unless text.nil? return self end def node_type :element end def xpath path_elements = [] cur = self path_elements << __to_xpath_helper( self ) while cur.parent cur = cur.parent path_elements << __to_xpath_helper( cur ) end return path_elements.reverse.join( "/" ) end ################################################# # Attributes # ################################################# def attribute( name, namespace=nil ) prefix = nil prefix = namespaces.index(namespace) if namespace prefix = nil if prefix == 'xmlns' attributes.get_attribute( "#{prefix ? prefix + ':' : ''}#{name}" ) end # Evaluates to +true+ if this element has any attributes set, false # otherwise. def has_attributes? return !@attributes.empty? end # Adds an attribute to this element, overwriting any existing attribute # by the same name. # key:: # can be either an Attribute or a String. If an Attribute, # the attribute is added to the list of Element attributes. If String, # the argument is used as the name of the new attribute, and the value # parameter must be supplied. # value:: # Required if +key+ is a String, and ignored if the first argument is # an Attribute. This is a String, and is used as the value # of the new Attribute. This should be the unnormalized value of the # attribute (without entities). # Returns:: the Attribute added # e = Element.new 'e' # e.add_attribute( 'a', 'b' ) #-> <e a='b'/> # e.add_attribute( 'x:a', 'c' ) #-> <e a='b' x:a='c'/> # e.add_attribute Attribute.new('b', 'd') #-> <e a='b' x:a='c' b='d'/> def add_attribute( key, value=nil ) if key.kind_of? Attribute @attributes << key else @attributes[key] = value end end # Add multiple attributes to this element. # hash:: is either a hash, or array of arrays # el.add_attributes( {"name1"=>"value1", "name2"=>"value2"} ) # el.add_attributes( [ ["name1","value1"], ["name2"=>"value2"] ] ) def add_attributes hash if hash.kind_of? Hash hash.each_pair {|key, value| @attributes[key] = value } elsif hash.kind_of? Array hash.each { |value| @attributes[ value[0] ] = value[1] } end end # Removes an attribute # key:: # either an Attribute or a String. In either case, the # attribute is found by matching the attribute name to the argument, # and then removed. If no attribute is found, no action is taken. # Returns:: # the attribute removed, or nil if this Element did not contain # a matching attribute # e = Element.new('E') # e.add_attribute( 'name', 'Sean' ) #-> <E name='Sean'/> # r = e.add_attribute( 'sur:name', 'Russell' ) #-> <E name='Sean' sur:name='Russell'/> # e.delete_attribute( 'name' ) #-> <E sur:name='Russell'/> # e.delete_attribute( r ) #-> <E/> def delete_attribute(key) attr = @attributes.get_attribute(key) attr.remove unless attr.nil? end ################################################# # Other Utilities # ################################################# # Get an array of all CData children. # IMMUTABLE def cdatas find_all { |child| child.kind_of? CData }.freeze end # Get an array of all Comment children. # IMMUTABLE def comments find_all { |child| child.kind_of? Comment }.freeze end # Get an array of all Instruction children. # IMMUTABLE def instructions find_all { |child| child.kind_of? Instruction }.freeze end # Get an array of all Text children. # IMMUTABLE def texts find_all { |child| child.kind_of? Text }.freeze end # == DEPRECATED # See REXML::Formatters # # Writes out this element, and recursively, all children. # output:: # output an object which supports '<< string'; this is where the # document will be written. # indent:: # An integer. If -1, no indenting will be used; otherwise, the # indentation will be this number of spaces, and children will be # indented an additional amount. Defaults to -1 # transitive:: # If transitive is true and indent is >= 0, then the output will be # pretty-printed in such a way that the added whitespace does not affect # the parse tree of the document # ie_hack:: # Internet Explorer is the worst piece of crap to have ever been # written, with the possible exception of Windows itself. Since IE is # unable to parse proper XML, we have to provide a hack to generate XML # that IE's limited abilities can handle. This hack inserts a space # before the /> on empty tags. Defaults to false # # out = '' # doc.write( out ) #-> doc is written to the string 'out' # doc.write( $stdout ) #-> doc written to the console def write(writer=$stdout, indent=-1, transitive=false, ie_hack=false) Kernel.warn("#{self.class.name}.write is deprecated. See REXML::Formatters") formatter = if indent > -1 if transitive REXML::Formatters::Transitive.new( indent, ie_hack ) else REXML::Formatters::Pretty.new( indent, ie_hack ) end else REXML::Formatters::Default.new( ie_hack ) end formatter.write( self, output ) end private def __to_xpath_helper node rv = node.expanded_name.clone if node.parent results = node.parent.find_all {|n| n.kind_of?(REXML::Element) and n.expanded_name == node.expanded_name } if results.length > 1 idx = results.index( node ) rv << "[#{idx+1}]" end end rv end # A private helper method def each_with_something( test, max=0, name=nil ) num = 0 child=nil @elements.each( name ){ |child| yield child if test.call(child) and num += 1 return if max>0 and num == max } end end ######################################################################## # ELEMENTS # ######################################################################## # A class which provides filtering of children for Elements, and # XPath search support. You are expected to only encounter this class as # the <tt>element.elements</tt> object. Therefore, you are # _not_ expected to instantiate this yourself. class Elements include Enumerable # Constructor # parent:: the parent Element def initialize parent @element = parent end # Fetches a child element. Filters only Element children, regardless of # the XPath match. # index:: # the search parameter. This is either an Integer, which # will be used to find the index'th child Element, or an XPath, # which will be used to search for the Element. <em>Because # of the nature of XPath searches, any element in the connected XML # document can be fetched through any other element.</em> <b>The # Integer index is 1-based, not 0-based.</b> This means that the first # child element is at index 1, not 0, and the +n+th element is at index # +n+, not <tt>n-1</tt>. This is because XPath indexes element children # starting from 1, not 0, and the indexes should be the same. # name:: # optional, and only used in the first argument is an # Integer. In that case, the index'th child Element that has the # supplied name will be returned. Note again that the indexes start at 1. # Returns:: the first matching Element, or nil if no child matched # doc = Document.new '<a><b/><c id="1"/><c id="2"/><d/></a>' # doc.root.elements[1] #-> <b/> # doc.root.elements['c'] #-> <c id="1"/> # doc.root.elements[2,'c'] #-> <c id="2"/> def []( index, name=nil) if index.kind_of? Integer raise "index (#{index}) must be >= 1" if index < 1 name = literalize(name) if name num = 0 child = nil @element.find { |child| child.kind_of? Element and (name.nil? ? true : child.has_name?( name )) and (num += 1) == index } else return XPath::first( @element, index ) #{ |element| # return element if element.kind_of? Element #} #return nil end end # Sets an element, replacing any previous matching element. If no # existing element is found ,the element is added. # index:: Used to find a matching element to replace. See [](). # element:: # The element to replace the existing element with # the previous element # Returns:: nil if no previous element was found. # # doc = Document.new '<a/>' # doc.root.elements[10] = Element.new('b') #-> <a><b/></a> # doc.root.elements[1] #-> <b/> # doc.root.elements[1] = Element.new('c') #-> <a><c/></a> # doc.root.elements['c'] = Element.new('d') #-> <a><d/></a> def []=( index, element ) previous = self[index] if previous.nil? @element.add element else previous.replace_with element end return previous end # Returns +true+ if there are no +Element+ children, +false+ otherwise def empty? @element.find{ |child| child.kind_of? Element}.nil? end # Returns the index of the supplied child (starting at 1), or -1 if # the element is not a child # element:: an +Element+ child def index element rv = 0 found = @element.find do |child| child.kind_of? Element and (rv += 1) and child == element end return rv if found == element return -1 end # Deletes a child Element # element:: # Either an Element, which is removed directly; an # xpath, where the first matching child is removed; or an Integer, # where the n'th Element is removed. # Returns:: the removed child # doc = Document.new '<a><b/><c/><c id="1"/></a>' # b = doc.root.elements[1] # doc.root.elements.delete b #-> <a><c/><c id="1"/></a> # doc.elements.delete("a/c[@id='1']") #-> <a><c/></a> # doc.root.elements.delete 1 #-> <a/> def delete element if element.kind_of? Element @element.delete element else el = self[element] el.remove if el end end # Removes multiple elements. Filters for Element children, regardless of # XPath matching. # xpath:: all elements matching this String path are removed. # Returns:: an Array of Elements that have been removed # doc = Document.new '<a><c/><c/><c/><c/></a>' # deleted = doc.elements.delete_all 'a/c' #-> [<c/>, <c/>, <c/>, <c/>] def delete_all( xpath ) rv = [] XPath::each( @element, xpath) {|element| rv << element if element.kind_of? Element } rv.each do |element| @element.delete element element.remove end return rv end # Adds an element # element:: # if supplied, is either an Element, String, or # Source (see Element.initialize). If not supplied or nil, a # new, default Element will be constructed # Returns:: the added Element # a = Element.new('a') # a.elements.add(Element.new('b')) #-> <a><b/></a> # a.elements.add('c') #-> <a><b/><c/></a> def add element=nil rv = nil if element.nil? Element.new("", self, @element.context) elsif not element.kind_of?(Element) Element.new(element, self, @element.context) else @element << element element.context = @element.context element end end alias :<< :add # Iterates through all of the child Elements, optionally filtering # them by a given XPath # xpath:: # optional. If supplied, this is a String XPath, and is used to # filter the children, so that only matching children are yielded. Note # that XPaths are automatically filtered for Elements, so that # non-Element children will not be yielded # doc = Document.new '<a><b/><c/><d/>sean<b/><c/><d/></a>' # doc.root.each {|e|p e} #-> Yields b, c, d, b, c, d elements # doc.root.each('b') {|e|p e} #-> Yields b, b elements # doc.root.each('child::node()') {|e|p e} # #-> Yields <b/>, <c/>, <d/>, <b/>, <c/>, <d/> # XPath.each(doc.root, 'child::node()', &block) # #-> Yields <b/>, <c/>, <d/>, sean, <b/>, <c/>, <d/> def each( xpath=nil, &block) XPath::each( @element, xpath ) {|e| yield e if e.kind_of? Element } end def collect( xpath=nil, &block ) collection = [] XPath::each( @element, xpath ) {|e| collection << yield(e) if e.kind_of?(Element) } collection end def inject( xpath=nil, initial=nil, &block ) first = true XPath::each( @element, xpath ) {|e| if (e.kind_of? Element) if (first and initial == nil) initial = e first = false else initial = yield( initial, e ) if e.kind_of? Element end end } initial end # Returns the number of +Element+ children of the parent object. # doc = Document.new '<a>sean<b/>elliott<b/>russell<b/></a>' # doc.root.size #-> 6, 3 element and 3 text nodes # doc.root.elements.size #-> 3 def size count = 0 @element.each {|child| count+=1 if child.kind_of? Element } count end # Returns an Array of Element children. An XPath may be supplied to # filter the children. Only Element children are returned, even if the # supplied XPath matches non-Element children. # doc = Document.new '<a>sean<b/>elliott<c/></a>' # doc.root.elements.to_a #-> [ <b/>, <c/> ] # doc.root.elements.to_a("child::node()") #-> [ <b/>, <c/> ] # XPath.match(doc.root, "child::node()") #-> [ sean, <b/>, elliott, <c/> ] def to_a( xpath=nil ) rv = XPath.match( @element, xpath ) return rv.find_all{|e| e.kind_of? Element} if xpath rv end private # Private helper class. Removes quotes from quoted strings def literalize name name = name[1..-2] if name[0] == ?' or name[0] == ?" #' name end end ######################################################################## # ATTRIBUTES # ######################################################################## # A class that defines the set of Attributes of an Element and provides # operations for accessing elements in that set. class Attributes < Hash # Constructor # element:: the Element of which this is an Attribute def initialize element @element = element end # 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' def [](name) attr = get_attribute(name) return attr.value unless attr.nil? return nil end def to_a values.flatten end # Returns the number of attributes the owning Element contains. # doc = Document "<a x='1' y='2' foo:x='3'/>" # doc.root.attributes.length #-> 3 def length c = 0 each_attribute { c+=1 } c end alias :size :length # Iterates over the attributes of an Element. Yields actual Attribute # nodes, not String values. # # doc = Document.new '<a x="1" y="2"/>' # doc.root.attributes.each_attribute {|attr| # p attr.expanded_name+" => "+attr.value # } 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 # Iterates over each attribute of an Element, yielding the expanded name # and value as a pair of Strings. # # doc = Document.new '<a x="1" y="2"/>' # doc.root.attributes.each {|name, value| p name+" => "+value } def each each_attribute do |attr| yield attr.expanded_name, attr.value end end # Fetches an attribute # name:: # the name by which to search for the attribute. Can be a # <tt>prefix:name</tt> 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" 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.expanded_name 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 # 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 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 # 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'] def prefixes ns = [] each_attribute do |attribute| ns << attribute.name if attribute.prefix == 'xmlns' end if @element.document and @element.document.doctype expn = @element.expanded_name 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 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.expanded_name 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 # 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'/>" 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 # Adds an attribute, overriding any existing attribute by the # same name. Namespaces are significant. # attribute:: An Attribute def add( attribute ) self[attribute.name] = attribute end alias :<< :add # 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 def delete_all( name ) rv = [] each_attribute { |attribute| rv << attribute if attribute.expanded_name == name } rv.each{ |attr| attr.remove } return rv end # 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 def get_attribute_ns(namespace, name) each_attribute() { |attribute| if name == attribute.name && namespace == attribute.namespace() return attribute end } nil end end end