//------------------------------------------------------------------------------ // // Copyright (c) Microsoft Corporation. All rights reserved. // //------------------------------------------------------------------------------ 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; /// /// Interacts with the parser to build a control. /// public class LinkButtonControlBuilder : ControlBuilder { /// /// /// Specifies whether white space literals are allowed. /// public override bool AllowWhitespaceLiterals() { return false; } } /// /// Constructs a link button and defines its properties. /// [ ControlBuilderAttribute(typeof(LinkButtonControlBuilder)), DataBindingHandler("System.Web.UI.Design.TextDataBindingHandler, " + AssemblyRef.SystemDesign), DefaultEvent("Click"), DefaultProperty("Text"), ToolboxData("<{0}:LinkButton runat=\"server\">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(); /// /// Initializes a new instance of the class. /// public LinkButton() : base(HtmlTextWriterTag.A) { } /// /// Specifies the command name that is propagated in the /// event along with the associated /// property. /// [ 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; } } /// /// Specifies the command argument that is propagated in the /// event along with the associated /// property. /// [ 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; } } /// /// 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. /// [ 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; } } /// /// The script that is executed on a client-side click. /// [ 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; } } /// /// Gets or sets the text display for the link button. /// [ 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; } } /// /// Occurs when the link button is clicked. /// [ WebCategory("Action"), WebSysDescription(SR.LinkButton_OnClick) ] public event EventHandler Click { add { Events.AddHandler(EventClick, value); } remove { Events.RemoveHandler(EventClick, value); } } /// /// Occurs when any item is clicked within the control tree. /// [ WebCategory("Action"), WebSysDescription(SR.Button_OnCommand) ] public event CommandEventHandler Command { add { Events.AddHandler(EventCommand, value); } remove { Events.RemoveHandler(EventCommand, value); } } /// /// /// Render the attributes on the begin tag. /// 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 // is a link to the root of the current directory. if (String.IsNullOrEmpty(postBackEventReference)) { postBackEventReference = "javascript:void(0)"; } writer.AddAttribute(HtmlTextWriterAttribute.Href, postBackEventReference); } } /// /// /// 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; } /// /// /// Load previously saved state. /// Overridden to synchronize Text property with LiteralContent. /// 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(); } } } /// /// Raises the event. /// protected virtual void OnClick(EventArgs e) { EventHandler onClickHandler = (EventHandler)Events[EventClick]; if (onClickHandler != null) onClickHandler(this,e); } /// /// Raises the event. /// 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); } /// /// /// Raises a event upon postback /// to the server, and a event if the /// is defined. /// void IPostBackEventHandler.RaisePostBackEvent(string eventArgument) { RaisePostBackEvent(eventArgument); } /// /// /// Raises a event upon postback /// to the server, and a event if the /// is defined. /// protected virtual void RaisePostBackEvent(string eventArgument) { ValidateEvent(this.UniqueID, eventArgument); if (CausesValidation) { Page.Validate(ValidationGroup); } OnClick(EventArgs.Empty); OnCommand(new CommandEventArgs(CommandName, CommandArgument)); } /// 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 } } } /// /// /// protected internal override void RenderContents(HtmlTextWriter writer) { if (HasRenderingData()) { base.RenderContents(writer); } else { writer.Write(Text); } } } }