/// <summary>
/// A collection is usually associated with a parent node (an HtmlElement, actually)
/// but you can pass null to implement an abstracted collection.
/// </summary>
/// <param name="parent">The parent element, or null if it is not appropriate</param>
internal HtmlNodeCollection(HtmlElement parent)
{
mParent = parent;
}
/// <summary>
/// Internal method to maintain the identity of the parent node.
/// </summary>
/// <param name="parentNode">The parent node of this one</param>
internal void SetParent(HtmlElement parentNode)
{
mParent = parentNode;
}
// Public constructor to create an empty collection.
public HtmlNodeCollection()
{
mParent = null;
}
/// <summary>
/// This constructor is used by the subclasses.
/// </summary>
protected HtmlNode()
{
mParent = null;
}
/// <summary>
/// This will create an empty collection of attributes.
/// </summary>
/// <param name="element"></param>
internal HtmlAttributeCollection(HtmlElement element)
{
mElement = element;
}
public HtmlAttributeCollection()
{
mElement = null;
}
/// <summary>
/// This will parse a string containing HTML and will produce a domain tree.
/// </summary>
/// <param name="html">The HTML to be parsed</param>
/// <returns>A tree representing the elements</returns>
public HtmlNodeCollection Parse(string html)
{
HtmlNodeCollection nodes = new HtmlNodeCollection(null);
html = PreprocessScript( html ,"script" );
html = PreprocessScript( html ,"style" );
html = RemoveComments( html );
html = RemoveSGMLComments( html );
StringCollection tokens = GetTokens( html );
int index = 0;
HtmlElement element = null;
while( index < tokens.Count )
{
if( "<".Equals( tokens[index] ) )
{
// Read open tag
index++;
if( index >= tokens.Count ) break;
string tag_name = tokens[index];
index++;
element = new HtmlElement( tag_name );
// read the attributes and values
while( index < tokens.Count && ! ">".Equals( tokens[index] ) && ! "/>".Equals( tokens[index] ) )
{
string attribute_name = tokens[ index ];
index++;
if( index < tokens.Count && "=".Equals( tokens[ index ] ) )
{
index++;
string attribute_value;
if( index < tokens.Count )
{
attribute_value = tokens[ index ];
}
else
{
attribute_value = null;
}
index++;
HtmlAttribute attribute = new HtmlAttribute( attribute_name , HtmlEncoder.DecodeValue( attribute_value ) );
element.Attributes.Add( attribute );
}
else if( index < tokens.Count )
{
// Null-value attribute
HtmlAttribute attribute = new HtmlAttribute( attribute_name , null );
element.Attributes.Add( attribute );
}
}
nodes.Add( element );
if( index < tokens.Count && "/>".Equals( tokens[ index ] ) )
{
element.IsTerminated = true;
index++;
element = null;
}
else if( index < tokens.Count && ">".Equals( tokens[ index ] ) )
{
index++;
}
}
else if( ">".Equals( tokens[index] ) )
{
index++;
}
else if( "</".Equals( tokens[index] ) )
{
// Read close tag
index++;
if( index >= tokens.Count ) break;
string tag_name = tokens[index];
index++;
int open_index = FindTagOpenNodeIndex( nodes , tag_name );
if( open_index != -1 )
{
MoveNodesDown( ref nodes , open_index + 1 , (HtmlElement)nodes[open_index] );
}
else
{
// Er, there is a close tag without an opening tag!!
}
// Skip to the end of this tag
while( index < tokens.Count && ! ">".Equals( tokens[ index ] ) )
{
index++;
}
if( index < tokens.Count && ">".Equals( tokens[ index ] ) )
{
index++;
}
element = null;
}
else
{
// Read text
string value = tokens[ index ];
if( mRemoveEmptyElementText )
{
value = RemoveWhitespace( value );
}
value = DecodeScript( value );
if( mRemoveEmptyElementText && value.Length == 0 )
{
// We do nothing
}
else
{
if( ! ( element != null && element.NoEscaping ) )
{
value = HtmlEncoder.DecodeValue( value );
}
HtmlText node = new HtmlText( value );
nodes.Add( node );
}
index++;
}
}
return nodes;
}
/// <summary>
/// This will move all the nodes from the specified index to the new parent.
/// </summary>
/// <param name="nodes">The collection of nodes</param>
/// <param name="node_index">The index of the first node (in the above collection) to move</param>
/// <param name="new_parent">The node which will become the parent of the moved nodes</param>
private void MoveNodesDown(ref HtmlNodeCollection nodes,int node_index,HtmlElement new_parent)
{
for( int i = node_index ; i < nodes.Count ; i++ )
{
((HtmlElement)new_parent).Nodes.Add( nodes[i] );
nodes[i].SetParent( new_parent );
}
int c = nodes.Count;
for( int i = node_index ; i < c ; i++ )
{
nodes.RemoveAt( node_index );
}
new_parent.IsExplicitlyTerminated = true;
}