|
//------------------------------------------------------------------------------
// <copyright file="LinkButton.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI.WebControls {
using System;
using System.ComponentModel;
using System.Drawing.Design;
using System.Web;
using System.Web.UI;
using System.Web.Util;
/// <devdoc>
/// <para>Interacts with the parser to build a <see cref='System.Web.UI.WebControls.LinkButton'/> control.</para>
/// </devdoc>
public class LinkButtonControlBuilder : ControlBuilder {
/// <internalonly/>
/// <devdoc>
/// <para>Specifies whether white space literals are allowed.</para>
/// </devdoc>
public override bool AllowWhitespaceLiterals() {
return false;
}
}
/// <devdoc>
/// <para>Constructs a link button and defines its properties.</para>
/// </devdoc>
[
ControlBuilderAttribute(typeof(LinkButtonControlBuilder)),
DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + AssemblyRef.SystemDesign),
DefaultEvent("Click"),
DefaultProperty("Text"),
ToolboxData("<{0}:LinkButton runat=\"server\">LinkButton</{0}:LinkButton>"),
Designer("System.Web.UI.Design.WebControls.LinkButtonDesigner, " + AssemblyRef.SystemDesign),
ParseChildren(false),
SupportsEventValidation
]
public class LinkButton : WebControl, IButtonControl, IPostBackEventHandler {
private bool _textSetByAddParsedSubObject = false;
private static readonly object EventClick = new object();
private static readonly object EventCommand = new object();
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.LinkButton'/> class.</para>
/// </devdoc>
public LinkButton() : base(HtmlTextWriterTag.A) {
}
/// <devdoc>
/// <para>Specifies the command name that is propagated in the
/// <see cref='System.Web.UI.WebControls.LinkButton.Command'/>event along with the associated <see cref='System.Web.UI.WebControls.LinkButton.CommandArgument'/>
/// property.</para>
/// </devdoc>
[
DefaultValue(""),
Themeable(false),
WebCategory("Behavior"),
WebSysDescription(SR.WebControl_CommandName)
]
public string CommandName {
get {
string s = (string)ViewState["CommandName"];
return((s == null) ? String.Empty : s);
}
set {
ViewState["CommandName"] = value;
}
}
/// <devdoc>
/// <para>Specifies the command argument that is propagated in the
/// <see langword='Command '/>event along with the associated <see cref='System.Web.UI.WebControls.LinkButton.CommandName'/>
/// property.</para>
/// </devdoc>
[
Bindable(true),
DefaultValue(""),
Themeable(false),
WebCategory("Behavior"),
WebSysDescription(SR.WebControl_CommandArgument)
]
public string CommandArgument {
get {
string s = (string)ViewState["CommandArgument"];
return((s == null) ? String.Empty : s);
}
set {
ViewState["CommandArgument"] = value;
}
}
/// <devdoc>
/// <para>Gets or sets whether pressing the button causes page validation to fire. This defaults to True so that when
/// using validation controls, the validation state of all controls are updated when the button is clicked, both
/// on the client and the server. Setting this to False is useful when defining a cancel or reset button on a page
/// that has validators.</para>
/// </devdoc>
[
DefaultValue(true),
Themeable(false),
WebCategory("Behavior"),
WebSysDescription(SR.Button_CausesValidation)
]
public virtual bool CausesValidation {
get {
object b = ViewState["CausesValidation"];
return((b == null) ? true : (bool)b);
}
set {
ViewState["CausesValidation"] = value;
}
}
/// <devdoc>
/// The script that is executed on a client-side click.
/// </devdoc>
[
DefaultValue(""),
Themeable(false),
WebCategory("Behavior"),
WebSysDescription(SR.Button_OnClientClick)
]
public virtual string OnClientClick {
get {
string s = (string)ViewState["OnClientClick"];
if (s == null) {
return String.Empty;
}
return s;
}
set {
ViewState["OnClientClick"] = value;
}
}
public override bool SupportsDisabledAttribute {
get {
return RenderingCompatibility < VersionUtil.Framework40;
}
}
internal override bool RequiresLegacyRendering {
get {
return true;
}
}
/// <devdoc>
/// <para>Gets or sets the text display for the link button.</para>
/// </devdoc>
[
Localizable(true),
Bindable(true),
WebCategory("Appearance"),
DefaultValue(""),
WebSysDescription(SR.LinkButton_Text),
PersistenceMode(PersistenceMode.InnerDefaultProperty)
]
public virtual string Text {
get {
object o = ViewState["Text"];
return((o == null) ? String.Empty : (string)o);
}
set {
if (HasControls()) {
Controls.Clear();
}
ViewState["Text"] = value;
}
}
[
DefaultValue(""),
Editor("System.Web.UI.Design.UrlEditor, " + AssemblyRef.SystemDesign, typeof(UITypeEditor)),
Themeable(false),
UrlProperty("*.aspx"),
WebCategory("Behavior"),
WebSysDescription(SR.Button_PostBackUrl)
]
public virtual string PostBackUrl {
get {
string s = (string)ViewState["PostBackUrl"];
return s == null? String.Empty : s;
}
set {
ViewState["PostBackUrl"] = value;
}
}
[
WebCategory("Behavior"),
Themeable(false),
DefaultValue(""),
WebSysDescription(SR.PostBackControl_ValidationGroup)
]
public virtual string ValidationGroup {
get {
string s = (string)ViewState["ValidationGroup"];
return((s == null) ? String.Empty : s);
}
set {
ViewState["ValidationGroup"] = value;
}
}
/// <devdoc>
/// <para>Occurs when the link button is clicked.</para>
/// </devdoc>
[
WebCategory("Action"),
WebSysDescription(SR.LinkButton_OnClick)
]
public event EventHandler Click {
add {
Events.AddHandler(EventClick, value);
}
remove {
Events.RemoveHandler(EventClick, value);
}
}
/// <devdoc>
/// <para>Occurs when any item is clicked within the <see cref='System.Web.UI.WebControls.LinkButton'/> control tree.</para>
/// </devdoc>
[
WebCategory("Action"),
WebSysDescription(SR.Button_OnCommand)
]
public event CommandEventHandler Command {
add {
Events.AddHandler(EventCommand, value);
}
remove {
Events.RemoveHandler(EventCommand, value);
}
}
/// <internalonly/>
/// <devdoc>
/// Render the attributes on the begin tag.
/// </devdoc>
protected override void AddAttributesToRender(HtmlTextWriter writer) {
// Make sure we are in a form tag with runat=server.
if (Page != null) {
Page.VerifyRenderingInServerForm(this);
}
// Need to merge the onclick attribute with the OnClientClick
string onClick = Util.EnsureEndWithSemiColon(OnClientClick);
if (HasAttributes) {
string userOnClick = Attributes["onclick"];
if (userOnClick != null) {
// We don't use Util.MergeScript because OnClientClick or
// onclick attribute are set by page developer directly. We
// should preserve the value without adding javascript prefix.
onClick += Util.EnsureEndWithSemiColon(userOnClick);
Attributes.Remove("onclick");
}
}
if (onClick.Length > 0) {
writer.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
}
bool effectiveEnabled = IsEnabled;
if (Enabled && !effectiveEnabled && SupportsDisabledAttribute) {
// We need to do the cascade effect on the server, because the browser
// only renders as disabled, but doesn't disable the functionality.
writer.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled");
}
base.AddAttributesToRender(writer);
if (effectiveEnabled && Page != null) {
//
PostBackOptions options = GetPostBackOptions();
string postBackEventReference = null;
if (options != null) {
postBackEventReference = Page.ClientScript.GetPostBackEventReference(options, true);
}
// If the postBackEventReference is empty, use a javascript no-op instead, since
// <a href="" /> is a link to the root of the current directory.
if (String.IsNullOrEmpty(postBackEventReference)) {
postBackEventReference = "javascript:void(0)";
}
writer.AddAttribute(HtmlTextWriterAttribute.Href, postBackEventReference);
}
}
/// <internalonly/>
/// <devdoc>
/// </devdoc>
protected override void AddParsedSubObject(object obj) {
if (HasControls()) {
base.AddParsedSubObject(obj);
}
else {
if (obj is LiteralControl) {
if (_textSetByAddParsedSubObject) {
Text += ((LiteralControl)obj).Text;
}
else {
Text = ((LiteralControl)obj).Text;
}
_textSetByAddParsedSubObject = true;
}
else {
string currentText = Text;
if (currentText.Length != 0) {
Text = String.Empty;
base.AddParsedSubObject(new LiteralControl(currentText));
}
base.AddParsedSubObject(obj);
}
}
}
// Returns the client post back options.
protected virtual PostBackOptions GetPostBackOptions() {
PostBackOptions options = new PostBackOptions(this, String.Empty);
options.RequiresJavaScriptProtocol = true;
if (!String.IsNullOrEmpty(PostBackUrl)) {
// VSWhidbey 424614: Since the url is embedded as javascript in attribute,
// we should match the same encoding as done on HyperLink.NavigateUrl value.
options.ActionUrl = HttpUtility.UrlPathEncode(ResolveClientUrl(PostBackUrl));
// Also, there is a specific behavior in IE that when the script
// is triggered in href attribute, the whole string will be
// decoded once before the code is run. This doesn't happen to
// onclick or other event attributes. So here we do an extra
// encoding to compensate the weird behavior on IE.
if (!DesignMode && Page != null &&
String.Equals(Page.Request.Browser.Browser, "IE", StringComparison.OrdinalIgnoreCase)) {
options.ActionUrl = Util.QuoteJScriptString(options.ActionUrl, true);
}
}
if (CausesValidation && Page.GetValidators(ValidationGroup).Count > 0) {
options.PerformValidation = true;
options.ValidationGroup = ValidationGroup;
}
return options;
}
/// <internalonly/>
/// <devdoc>
/// Load previously saved state.
/// Overridden to synchronize Text property with LiteralContent.
/// </devdoc>
protected override void LoadViewState(object savedState) {
if (savedState != null) {
base.LoadViewState(savedState);
string s = (string)ViewState["Text"];
// Dev10 703061 If Text is set, we want to clear out any child controls, but not dirty viewstate
if (s != null && HasControls()) {
Controls.Clear();
}
}
}
/// <devdoc>
/// <para>Raises the <see langword='Click '/> event.</para>
/// </devdoc>
protected virtual void OnClick(EventArgs e) {
EventHandler onClickHandler = (EventHandler)Events[EventClick];
if (onClickHandler != null) onClickHandler(this,e);
}
/// <devdoc>
/// <para>Raises the <see langword='Command'/> event.</para>
/// </devdoc>
protected virtual void OnCommand(CommandEventArgs e) {
CommandEventHandler onCommandHandler = (CommandEventHandler)Events[EventCommand];
if (onCommandHandler != null)
onCommandHandler(this,e);
// Command events are bubbled up the control heirarchy
RaiseBubbleEvent(this, e);
}
/// <internalonly/>
/// <devdoc>
/// <para>Raises a <see langword='Click '/>event upon postback
/// to the server, and a <see langword='Command'/> event if the <see cref='System.Web.UI.WebControls.LinkButton.CommandName'/>
/// is defined.</para>
/// </devdoc>
void IPostBackEventHandler.RaisePostBackEvent(string eventArgument) {
RaisePostBackEvent(eventArgument);
}
/// <internalonly/>
/// <devdoc>
/// <para>Raises a <see langword='Click '/>event upon postback
/// to the server, and a <see langword='Command'/> event if the <see cref='System.Web.UI.WebControls.LinkButton.CommandName'/>
/// is defined.</para>
/// </devdoc>
protected virtual void RaisePostBackEvent(string eventArgument) {
ValidateEvent(this.UniqueID, eventArgument);
if (CausesValidation) {
Page.Validate(ValidationGroup);
}
OnClick(EventArgs.Empty);
OnCommand(new CommandEventArgs(CommandName, CommandArgument));
}
/// <internalonly/>
protected internal override void OnPreRender(EventArgs e) {
base.OnPreRender(e);
if (Page != null && Enabled) {
Page.RegisterPostBackScript();
if ((CausesValidation && Page.GetValidators(ValidationGroup).Count > 0) ||
!String.IsNullOrEmpty(PostBackUrl)) {
Page.RegisterWebFormsScript(); // VSWhidbey 489577
}
}
}
/// <internalonly/>
/// <devdoc>
/// </devdoc>
protected internal override void RenderContents(HtmlTextWriter writer) {
if (HasRenderingData()) {
base.RenderContents(writer);
}
else {
writer.Write(Text);
}
}
}
}
|