Class: HTMLTree::Element

Inherits:
Object
  • Object
show all
Includes:
TreeElement
Defined in:
lib/html/element.rb,
lib/html/xpath.rb

Overview

This is a TreeElement that represents tagged items in an HTML document.

Instance Method Summary collapse

Methods included from TreeElement

#add_child, #children, #content, #dump, #each, #has_children?, #parent, #parent=, #remove_child, #rexml_match, #root

Instance Method Details

#[](name) ⇒ Object

Return the value of a single attribute (a String or Array).



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# File 'lib/html/element.rb', line 245

def [](name); attribute(name); end

#[]=(name, *values) ⇒ Object

Replace an attribute.



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# File 'lib/html/element.rb', line 248

def []=(name, *values)
  @_attributes[name] = values.size > 1 ? values : values[0]
  @_attribute_order.delete(name)
  self
end

#add_attribute(name, *values) ⇒ Object

Append an attribute. values are first flattened into an Array, then converted into strings.

If there is a single attribute value, it will appear as a String, otherwise it will be an Array of Strings.

Example:

element.add_attribute("width", "123")
element.add_attribute("value", [ "a", "b" ])



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# File 'lib/html/element.rb', line 188

def add_attribute(name, *values)
  values = values.flatten.collect { |ea| ea.to_s.strip }
  name = name.downcase
  if @_attributes.include?(name)
    @_attributes[name] = @_attributes[name].to_a + values
  else
    @_attributes[name] = values.size > 1 ? values : values[0]
  end
  @_attribute_order << name
  self
end

#as_rexml_document(rparent = nil, context = {}) ⇒ Object

convert the given HTMLTree::Element (or HTMLTree::Document) into a REXML::Element or REXML::Document, ready to use REXML::XPath on. Note that this caches the tree; further changes to my tree will not be reflected in subsequent calls



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# File 'lib/html/xpath.rb', line 30

def as_rexml_document(rparent = nil, context = {})
  return @_rexml_tree if @_rexml_tree
  node = REXML::Element.new( tag, rparent, context )
  attribute_order().each { |attr|
    node.add_attribute(attr, attribute(attr).to_s)
  }
  children().each { |child|
    childNode = child.as_rexml_document(node, context)
  }
  @_rexml_tree = node
end

#attribute(name) ⇒ Object

Return the value of a single attribute (a String or Array).



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# File 'lib/html/element.rb', line 242

def attribute(name); @_attributes[name]; end

#attribute_order ⇒ Object

Return the order of my attributes



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# File 'lib/html/element.rb', line 239

def attribute_order; @_attribute_order; end

#attributes ⇒ Object

Return my attributes Hash.



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# File 'lib/html/element.rb', line 236

def attributes; @_attributes; end

#can_have_children? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/html/element.rb', line 164

def can_have_children?; true; end

#data? ⇒ Boolean

Return true if I’m data instead of a tag

Returns:

  • (Boolean) 


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# File 'lib/html/element.rb', line 167

def data?; false; end

#elements ⇒ Object

Return the children of this node that are elements (not data)



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# File 'lib/html/element.rb', line 231

def elements
  children.select { |node| node.is_a? Element }
end

#path ⇒ Object

Return the path to this element from the root



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# File 'lib/html/element.rb', line 214

def path
  path = []
  node = self
  while node do
    path.unshift node.tag
    node = node.parent
  end
  path.join(".")
end

#show_structure(indent = 0) ⇒ Object 



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# File 'lib/html/element.rb', line 224

def show_structure(indent = 0)
  puts(' ' * indent) + path
  elements.each { |node| node.show_structure(indent + 2) }
  nil
end

#tag ⇒ Object

Return my tag (should be a String)



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# File 'lib/html/element.rb', line 201

def tag; @_tag; end

#tag_info ⇒ Object

Return an HTML::Tag for further information, or nil if this is an unknown tag.



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# File 'lib/html/element.rb', line 205

def tag_info
  begin
    HTML::Tag.named(@_tag)
  rescue NoSuchHTMLTagError
    nil
  end
end

#to_s ⇒ Object 



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# File 'lib/html/element.rb', line 169

def to_s
  a = [ "<", tag ]
  @_attribute_order.each { |k|
    v = @_attributes[k]
    a << " #{k.to_s}=\"#{v.to_s}\""
  }
  a << ">"
  a.join('')
end

#write(io) ⇒ Object

Print me (and my descendents) on the given IO stream.



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# File 'lib/html/element.rb', line 255

def write(io)
  io << self
  children.each { |t| t.write(io) }
  unless tag_info.is_empty_element
    io.puts( "</#{tag()}>" )
  end
end