/// <summary>
/// Returns the pos'th child with the given tagName.
/// </summary>
public static IHtmlElement GetChildAt(this IHtmlElement parent, string tagName, int pos)
{
parent.Require(x => parent != null);
tagName.Require(x => !string.IsNullOrEmpty(tagName));
int childPos = 0;
foreach (var child in parent.Children)
{
if (child.TagName.Equals(tagName, StringComparison.OrdinalIgnoreCase))
{
if (childPos == pos)
{
return(child);
}
childPos++;
}
}
return(null);
// TODO: this could happen if the site has been changed and the
// path is no longer valid
//throw new ArgumentException( "Could not find child for path: " + tagName + "[" + pos + "]" );
}
/// <summary>
/// Returns the position of the HtmlElement in its parents children.
/// </summary>
public static int GetChildPos(this IHtmlElement element)
{
element.Require(x => element != null);
if (element.Parent == null)
{
// assume its valid HTML with <html/> as root element
return(0);
}
int childPos = 0;
foreach (var child in element.Parent.Children)
{
if (child.TagName.Equals(element.TagName, StringComparison.OrdinalIgnoreCase))
{
if (child == element)
{
return(childPos);
}
childPos++;
}
}
//throw new ArgumentException( "Could not find child pos for child: " + e.TagName );
return(-1);
}
/// <summary>
/// Searches for the parent of the given elment for which <c>cond</c>
/// gets <c>true</c>.
/// Stops the search and returns null if <c>abortIf</c> gets true before
/// <c>cond</c> gets true.
/// The given element must not fullfil the abort condition.
/// </summary>
/// <returns>the parent found if any, null otherwise</returns>
public static IHtmlElement FindParent(this IHtmlElement start, Predicate <IHtmlElement> cond, Predicate <IHtmlElement> abortIf)
{
start.Require(x => start != null);
start.Require(x => !abortIf(start));
var parent = start.Parent;
while (parent != null && !abortIf(parent))
{
if (cond(parent))
{
return(parent);
}
parent = parent.Parent;
}
return(null);
}
/// <summary>
/// Gets the complete row of the given cell.
/// </summary>
public static IEnumerable <IHtmlElement> GetRow(IHtmlElement cell)
{
cell.Require(x => cell != null);
var row = GetEmbeddingTR(cell);
if (row == null)
{
throw new ArgumentException("Element does not point to cell inside table row");
}
return(row.Children);
}
/// <summary>
/// Searches for the table which embedds the given element.
/// If the start element is a TABLE element, this one is returned.
/// </summary>
public static HtmlTable FindEmbeddingTable(this IHtmlElement start)
{
start.Require(x => start != null);
if (start.TagName == "TABLE")
{
return(new HtmlTable(start));
}
var table = start.FindParent(p => p.TagName == "TABLE");
return(table == null ? null : new HtmlTable(table));
}
/// <summary>
/// Returns the TR element embedding the given element.
/// If the given element itself is a TR, this one is returned.
/// </summary>
public static IHtmlElement GetEmbeddingTR(IHtmlElement e)
{
e.Require(x => e != null);
if (e.TagName == "TR")
{
return(e);
}
else
{
var parent = e.FindParent(p => p.TagName == "TR", p => e.IsTableOrTBody());
return(parent == null ? null : parent);
}
}
/// <summary>
/// Returns the <see cref="HtmlPath"/> of the HtmlElement up to root.
/// </summary>
public static HtmlPath GetPath(this IHtmlElement element)
{
element.Require(x => element != null);
HtmlPath path = new HtmlPath();
var cur = element;
while (cur.Parent != null)
{
path.Elements.Insert(0, new HtmlPathElement(cur.TagName, cur.GetChildPos()));
cur = cur.Parent;
}
return(path);
}
/// <summary>
/// Gets the complete column of the given cell.
/// <remarks>Attention: Handling "colspan" is not implemented.
/// A TR without any TD is skipped.</remarks>
/// </summary>
public static IEnumerable <IHtmlElement> GetColumn(IHtmlElement cell)
{
cell.Require(x => cell != null);
HtmlTable table = cell.FindEmbeddingTable();
if (table == null)
{
throw new ArgumentException("Element does not point to into table");
}
int colIdx = cell.GetChildPos();
foreach (object row in table.TableBody.Children)
{
IHtmlElement e = ((IHtmlElement)row).GetChildAt("TD", colIdx);
if (e == null)
{
continue;
}
yield return(e);
}
}
/// <summary>
/// Gets the complete row of the given cell.
/// </summary>
public static IEnumerable<IHtmlElement> GetRow( IHtmlElement cell )
{
cell.Require( x => cell != null );
var row = GetEmbeddingTR( cell );
if ( row == null )
{
throw new ArgumentException( "Element does not point to cell inside table row" );
}
return row.Children;
}
/// <summary>
/// Returns the TR element embedding the given element.
/// If the given element itself is a TR, this one is returned.
/// </summary>
public static IHtmlElement GetEmbeddingTR( IHtmlElement e )
{
e.Require( x => e != null );
if ( e.TagName == "TR" )
{
return e;
}
else
{
var parent = e.FindParent( p => p.TagName == "TR", p => e.IsTableOrTBody() );
return (parent == null ? null : parent);
}
}
/// <summary>
/// Gets the complete column of the given cell.
/// <remarks>Attention: Handling "colspan" is not implemented.
/// A TR without any TD is skipped.</remarks>
/// </summary>
public static IEnumerable<IHtmlElement> GetColumn( IHtmlElement cell )
{
cell.Require( x => cell != null );
HtmlTable table = cell.FindEmbeddingTable();
if ( table == null )
{
throw new ArgumentException( "Element does not point to into table" );
}
int colIdx = cell.GetChildPos();
foreach ( object row in table.TableBody.Children )
{
IHtmlElement e = ((IHtmlElement)row).GetChildAt( "TD", colIdx );
if ( e == null )
{
continue;
}
yield return e;
}
}
