//
// System.Web.UI.HtmlControls.HtmlHead
//
// Authors:
// Lluis Sanchez Gual (lluis@novell.com)
//
// Copyright (C) 2004-2010 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.ComponentModel;
using System.Collections;
using System.Security.Permissions;
using System.Web.UI.WebControls;
namespace System.Web.UI.HtmlControls
{
// CAS - no InheritanceDemand here as the class is sealed
[AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
// attributes
[ControlBuilder (typeof(HtmlHeadBuilder))]
public sealed class HtmlHead: HtmlGenericControl, IParserAccessor
{
string descriptionText;
string keywordsText;
HtmlMeta descriptionMeta;
HtmlMeta keywordsMeta;
string titleText;
HtmlTitle title;
//Hashtable metadata;
StyleSheetBag styleSheet;
public HtmlHead(): base("head") {}
public HtmlHead (string tag) : base (tag)
{
}
protected internal override void OnInit (EventArgs e)
{
base.OnInit (e);
Page page = Page;
if (page == null)
throw new HttpException ("The control requires a page.");
//You can only have one control on a page.
if(page.Header != null)
throw new HttpException ("You can only have one control on a page.");
page.SetHeader (this);
}
protected internal override void RenderChildren (HtmlTextWriter writer)
{
base.RenderChildren (writer);
if (title == null) {
writer.RenderBeginTag (HtmlTextWriterTag.Title);
if (!String.IsNullOrEmpty (titleText))
writer.Write (titleText);
writer.RenderEndTag ();
}
if (descriptionMeta == null && descriptionText != null) {
writer.AddAttribute ("name", "description");
writer.AddAttribute ("content", HttpUtility.HtmlAttributeEncode (descriptionText));
writer.RenderBeginTag (HtmlTextWriterTag.Meta);
writer.RenderEndTag ();
}
if (keywordsMeta == null && keywordsText != null) {
writer.AddAttribute ("name", "keywords");
writer.AddAttribute ("content", HttpUtility.HtmlAttributeEncode (keywordsText));
writer.RenderBeginTag (HtmlTextWriterTag.Meta);
writer.RenderEndTag ();
}
if (styleSheet != null)
styleSheet.Render (writer);
}
protected internal override void AddedControl (Control control, int index)
{
//You can only have one element within the <head> element.
HtmlTitle t = control as HtmlTitle;
if (t != null) {
if (title != null)
throw new HttpException ("You can only have one <title> element within the <head> element.");
title = t;
}
HtmlMeta meta = control as HtmlMeta;
if (meta != null) {
if (String.Compare ("keywords", meta.Name, StringComparison.OrdinalIgnoreCase) == 0)
keywordsMeta = meta;
else if (String.Compare ("description", meta.Name, StringComparison.OrdinalIgnoreCase) == 0)
descriptionMeta = meta;
}
base.AddedControl (control, index);
}
protected internal override void RemovedControl (Control control)
{
if (title == control)
title = null;
if (keywordsMeta == control)
keywordsMeta = null;
else if (descriptionMeta == control)
descriptionMeta = null;
base.RemovedControl (control);
}
public string Description {
get {
if (descriptionMeta != null)
return descriptionMeta.Content;
return descriptionText;
}
set {
if (descriptionMeta != null)
descriptionMeta.Content = value;
else
descriptionText = value;
}
}
public string Keywords {
get {
if (keywordsMeta != null)
return keywordsMeta.Content;
return keywordsText;
}
set {
if (keywordsMeta != null)
keywordsMeta.Content = value;
else
keywordsText = value;
}
}
public IStyleSheet StyleSheet {
get {
if (styleSheet == null) styleSheet = new StyleSheetBag ();
return styleSheet;
}
}
public string Title {
get {
if (title != null)
return title.Text;
else
return titleText;
}
set {
if (title != null)
title.Text = value;
else
titleText = value;
}
}
}
internal class StyleSheetBag: IStyleSheet
{
ArrayList entries = new ArrayList ();
internal class StyleEntry
{
public Style Style;
public string Selection;
public IUrlResolutionService UrlResolver;
}
public StyleSheetBag ()
{
}
public void CreateStyleRule (Style style, IUrlResolutionService urlResolver, string selection)
{
StyleEntry entry = new StyleEntry ();
entry.Style = style;
entry.UrlResolver = urlResolver;
entry.Selection = selection;
entries.Add (entry);
}
public void RegisterStyle (Style style, IUrlResolutionService urlResolver)
{
for (int n=0; n<entries.Count; n++) {
if (((StyleEntry)entries[n]).Style == style)
return;
}
string name = "aspnet_" + entries.Count;
style.SetRegisteredCssClass (name);
CreateStyleRule (style, urlResolver, "." + name);
}
public void Render (HtmlTextWriter writer)
{
writer.AddAttribute ("type", "text/css", false);
writer.RenderBeginTag (HtmlTextWriterTag.Style);
foreach (StyleEntry entry in entries) {
CssStyleCollection sts = entry.Style.GetStyleAttributes (entry.UrlResolver);
writer.Write ("\n" + entry.Selection + " {" + sts.Value + "}");
}
writer.RenderEndTag ();
}
}
}