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//------------------------------------------------------------------------------
// <copyright file="ContentPlaceHolder.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI.WebControls {
using System;
using System.Collections;
using System.ComponentModel;
using System.Web.UI;
using System.Web.Util;
internal class ContentPlaceHolderBuilder : ControlBuilder {
private string _contentPlaceHolderID;
private string _templateName;
internal string Name { get { return _templateName; } }
public override void Init(TemplateParser parser, ControlBuilder parentBuilder,
Type type, string tagName, string ID, IDictionary attribs) {
// Copy the ID so that it will be available when BuildObject is called
_contentPlaceHolderID = ID;
if (parser.FInDesigner) {
// shortcut for designer
base.Init(parser, parentBuilder, type, tagName, ID, attribs);
return;
}
if (String.IsNullOrEmpty(ID)) {
throw new HttpException(SR.GetString(SR.Control_Missing_Attribute, "ID", type.Name));
}
_templateName = ID;
MasterPageParser masterPageParser = parser as MasterPageParser;
if (masterPageParser == null) {
throw new HttpException(SR.GetString(SR.ContentPlaceHolder_only_in_master));
}
base.Init(parser, parentBuilder, type, tagName, ID, attribs);
if (masterPageParser.PlaceHolderList.Contains(Name))
throw new HttpException(SR.GetString(SR.ContentPlaceHolder_duplicate_contentPlaceHolderID, Name));
masterPageParser.PlaceHolderList.Add(Name);
}
public override object BuildObject() {
MasterPage masterPage = TemplateControl as MasterPage;
Debug.Assert(masterPage != null || InDesigner);
// Instantiate the ContentPlaceHolder
ContentPlaceHolder cph = (ContentPlaceHolder) base.BuildObject();
// If the page is providing content, instantiate it in the holder
if (PageProvidesMatchingContent(masterPage)) {
ITemplate tpl = ((System.Web.UI.ITemplate)(masterPage.ContentTemplates[_contentPlaceHolderID]));
masterPage.InstantiateInContentPlaceHolder(cph, tpl);
}
return cph;
}
internal override void BuildChildren(object parentObj) {
MasterPage masterPage = TemplateControl as MasterPage;
// If the page is providing content, don't call the base, which would
// instantiate the default content (which we don't want)
if (PageProvidesMatchingContent(masterPage))
return;
base.BuildChildren(parentObj);
}
private bool PageProvidesMatchingContent(MasterPage masterPage) {
if (masterPage != null && masterPage.ContentTemplates != null
&& masterPage.ContentTemplates.Contains(_contentPlaceHolderID)) {
return true;
}
return false;
}
}
// Factory used to efficiently create builder instances
internal class ContentPlaceHolderBuilderFactory: IWebObjectFactory {
object IWebObjectFactory.CreateInstance() {
return new ContentPlaceHolderBuilder();
}
}
[ControlBuilderAttribute(typeof(ContentPlaceHolderBuilder))]
[Designer("System.Web.UI.Design.WebControls.ContentPlaceHolderDesigner, " + AssemblyRef.SystemDesign)]
[ToolboxItemFilter("System.Web.UI")]
[ToolboxItemFilter("Microsoft.VisualStudio.Web.WebForms.MasterPageWebFormDesigner", ToolboxItemFilterType.Require)]
[ToolboxData("<{0}:ContentPlaceHolder runat=\"server\"></{0}:ContentPlaceHolder>")]
public class ContentPlaceHolder : Control, INonBindingContainer {
}
}
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