HtmlForm.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / HtmlForm.cs / 1305376 / HtmlForm.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

// HtmlForm.cs 
// 

namespace System.Web.UI.HtmlControls { 
    using System.ComponentModel;
    using System;
    using System.Collections;
    using System.Globalization; 
    using System.IO;
    using System.Text; 
    using System.Web.Configuration; 
    using System.Web.Util;
    using System.Web.UI; 
    using System.Web.UI.WebControls;
    using System.Web.Security;
    using System.Security.Permissions;
 

    ///  
    ///     
    ///       The  class defines the methods, properties, and
    ///       events for the HtmlForm control. This class provides programmatic access to the 
    ///       HTML <form> element on the server.
    ///    
    /// 
    public class HtmlForm: HtmlContainerControl { 
        private string _defaultFocus;
        private string _defaultButton; 
        private bool _submitDisabledControls; 
        private const string _aspnetFormID = "aspnetForm";
 

        /// 
        /// 
        public HtmlForm() : base("form") { 
        }
 
        [ 
        WebCategory("Behavior"),
        DefaultValue(""), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
        public string Action {
            get { 
                string s = Attributes["action"];
                return ((s != null) ? s : String.Empty); 
            } 
            set {
                Attributes["action"] = MapStringAttributeToString(value); 
            }
        }

        ///  
        ///     Gets or sets default button for the form
        ///  
        [ 
        WebCategory("Behavior"),
        DefaultValue(""), 
        ]
        public string DefaultButton {
            get {
                if (_defaultButton == null) { 
                    return String.Empty;
                } 
                return _defaultButton; 
            }
            set { 
                _defaultButton = value;
            }
        }
 

        ///  
        ///     Gets or sets default focused control for the form 
        /// 
        [ 
        WebCategory("Behavior"),
        DefaultValue(""),
        ]
        public string DefaultFocus { 
            get {
                if (_defaultFocus == null) { 
                    return String.Empty; 
                }
                return _defaultFocus; 
            }
            set {
                _defaultFocus = value;
            } 
        }
 
        /* 
         * Encode Type property.
         */ 

        /// 
        ///    
        ///       Gets or sets the Enctype attribute of the form. This is 
        ///       the encoding type that browsers
        ///       use when posting the form's data to the server. 
        ///     
        /// 
        [ 
        WebCategory("Behavior"),
        DefaultValue(""),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ] 
        public string Enctype {
            get { 
                string s = Attributes["enctype"]; 
                return((s != null) ? s : String.Empty);
            } 
            set {
                Attributes["enctype"] = MapStringAttributeToString(value);
            }
        } 

        /* 
         * Method property. 
         */
 
        /// 
        ///    
        ///       Gets or sets the Method attribute for the form. This defines how a browser
        ///       posts form data to the server for processing. The two common methods supported 
        ///       by all browsers are GET and POST.
        ///     
        ///  
        [
        WebCategory("Behavior"), 
        DefaultValue(""),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
        public string Method { 
            get {
                string s = Attributes["method"]; 
                return((s != null) ? s : "post"); 
            }
            set { 
                Attributes["method"] = MapStringAttributeToString(value);
            }
        }
 
        /*
         * Name property. 
         */ 

        ///  
        ///    
        ///       Gets the value of the HTML Name attribute that will be rendered to the
        ///       browser.
        ///     
        /// 
        [ 
        WebCategory("Appearance"), 
        DefaultValue(""),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden) 
        ]
        public virtual string Name {
            get {
                return UniqueID; 
            }
            set { 
                // no-op setter to prevent the name from being set 
            }
        } 


        /// 
        /// If true, forces controls disabled on the client to submit their values (thus preserving their previous postback state) 
        /// 
        [ 
        WebCategory("Behavior"), 
        DefaultValue(false)
        ] 
        public virtual bool SubmitDisabledControls {
            get {
                return _submitDisabledControls;
            } 
            set {
                _submitDisabledControls = value; 
            } 
        }
 
        /*
         * Target property.
         */
 
        /// 
        ///     
        ///       Gets or sets the Uri of the frame or window to render the results of a Form 
        ///       POST request. Developers can use this property to redirect these results to
        ///       another browser window or frame. 
        ///    
        /// 
        [
        WebCategory("Behavior"), 
        DefaultValue(""),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden) 
        ] 
        public string Target {
            get { 
                string s = Attributes["target"];
                return((s != null) ? s : String.Empty);
            }
 
            set {
                Attributes["target"] = MapStringAttributeToString(value); 
            } 
        }
 

        /// 
        /// Overridden to return a constant value or tack the ID onto the same constant value.
        /// This fixes a bug in PocketPC which doesn't allow the name and ID of a form to be different 
        /// 
        public override string UniqueID { 
            get { 
                if (NamingContainer == Page) {
                    return base.UniqueID; 
                }
                else if (this.EffectiveClientIDMode != ClientIDMode.AutoID) {
                    return ID ?? _aspnetFormID;
                } 

                return _aspnetFormID; 
            } 
        }
 
        public override string ClientID {
            get {
                if (this.EffectiveClientIDMode != ClientIDMode.AutoID) {
                    return ID; 
                }
                return base.ClientID; 
            } 
        }
 
        protected internal override void Render(HtmlTextWriter output) {
            Page p = Page;
            if (p == null)
                throw new HttpException(SR.GetString(SR.Form_Needs_Page)); 

#pragma warning disable 0618    // To avoid deprecation warning 
            if (p.SmartNavigation) { 
#pragma warning restore 0618
                ((IAttributeAccessor)this).SetAttribute("__smartNavEnabled", "true"); 

                // Output the IFrame
                StringBuilder sb = new StringBuilder("");
                output.WriteLine(sb.ToString()); 
            } 

            base.Render(output); 
        }

        private string GetActionAttribute() {
            // If the Action property is nonempty, we use it instead of the current page.  This allows the developer 
            // to support scenarios like PathInfo, UrlMapping, etc. (DevDiv Bugs 164390)
            string actionProperty = Action; 
            if (!String.IsNullOrEmpty(actionProperty)) { 
                return actionProperty;
            } 

            string action;
            VirtualPath clientFilePath = Context.Request.ClientFilePath;
 
            // ASURT 15075/11054/59970: always set the action to the current page.
            // DevDiv Servicing 215795/Dev10 567580: The IIS URL Rewrite module and other rewrite 
            // scenarios need the postback action to be the original URL.  Note however, if Server.Transfer/Execute 
            // is used, the action will be set to the transferred/executed page, that is, the value of
            // CurrentExecutionFilePathObject.  This is because of ASURT 59970 and the document attached to 
            // that bug, which indirectly states that things should behave this way when Transfer/Execute is used.
            if (Context.ServerExecuteDepth == 0) {
                // There hasn't been any Server.Transfer or RewritePath.
                // ASURT 15979: need to use a relative path, not absolute 
                action = clientFilePath.VirtualPathString;
                int iPos = action.LastIndexOf('/'); 
                if (iPos >= 0) { 
                    action = action.Substring(iPos+1);
                } 
            }
            else {
                VirtualPath currentFilePath = Context.Request.CurrentExecutionFilePathObject;
                // Server.Transfer or RewritePath case.  We need to make the form action relative 
                // to the original ClientFilePath (since that's where the browser thinks we are).
                currentFilePath = clientFilePath.MakeRelative(currentFilePath); 
                action = currentFilePath.VirtualPathString; 
            }
 
            // VSWhidbey 202380: If cookieless is on, we need to add the app path modifier to the form action
            bool cookieless = CookielessHelperClass.UseCookieless(Context, false, FormsAuthentication.CookieMode);
            if (cookieless && Context.Request != null && Context.Response != null) {
                action = Context.Response.ApplyAppPathModifier(action); 
            }
 
            // We should never return an empty action. 
            Debug.Assert(!String.IsNullOrEmpty(action));
 
            string queryString = Page.ClientQueryString;
            // ASURT 15355: Don't lose the query string if there is one.
            // In scriptless mobile HTML, we prepend __EVENTTARGET, et. al. to the query string.  These have to be
            // removed from the form action.  Use new HttpValueCollection to leverage ToString(bool encoded). 
            if (!String.IsNullOrEmpty(queryString)) {
                action += "?" + queryString; 
            } 

            return action; 
        }


        ///  
        /// 
        ///     Call RegisterViewStateHandler(). 
        ///  
        protected internal override void OnInit(EventArgs e) {
            base.OnInit(e); 

            Page.SetForm(this);

            // Make sure view state is calculated (see ASURT 73020) 
            Page.RegisterViewStateHandler();
        } 
 

        ///  
        /// Overridden to handle focus stuff
        /// 
        protected internal override void OnPreRender(EventArgs e) {
            base.OnPreRender(e); 

#pragma warning disable 0618    // To avoid deprecation warning 
            if (Page.SmartNavigation) { 
#pragma warning restore 0618
                // Register the smartnav script file reference so it gets rendered 
                Page.ClientScript.RegisterClientScriptResource(typeof(HtmlForm), "SmartNav.js");
            }
        }
 

        ///  
        ///  
        /// 
        protected override void RenderAttributes(HtmlTextWriter writer) { 
            ArrayList invalidAttributes = new ArrayList();
            foreach (String key in Attributes.Keys) {
                if (!writer.IsValidFormAttribute(key)) {
                    invalidAttributes.Add(key); 
                }
            } 
 
            foreach (String key in invalidAttributes) {
                Attributes.Remove(key); 
            }

            bool enableLegacyRendering = EnableLegacyRendering;
 
            Page page = Page;
            if (writer.IsValidFormAttribute("name")) { 
                // DevDiv 27328 Do not render name attribute for uplevel browser 
                if (page != null && page.RequestInternal != null &&
                    RenderingCompatibility < VersionUtil.Framework40 && 
                    (page.RequestInternal.Browser.W3CDomVersion.Major == 0 ||
                     page.XhtmlConformanceMode != XhtmlConformanceMode.Strict)) {
                    writer.WriteAttribute("name", Name);
                } 
                Attributes.Remove("name");
            } 
 
            writer.WriteAttribute("method", Method);
            Attributes.Remove("method"); 

            // Encode the action attribute - ASURT 66784
            writer.WriteAttribute("action", GetActionAttribute(), true /*encode*/);
            Attributes.Remove("action"); 

            // see if the page has a submit event 
            if (page != null) { 
                string onSubmit = page.ClientOnSubmitEvent;
                if (!String.IsNullOrEmpty(onSubmit)) { 
                    if (Attributes["onsubmit"] != null) {
                        // If there was an onsubmit on the form, register it as an onsubmit statement and remove it from the attribute collection
                        string formOnSubmit = Attributes["onsubmit"];
                        if (formOnSubmit.Length > 0) { 
                            if (!StringUtil.StringEndsWith(formOnSubmit, ';')) {
                                formOnSubmit += ";"; 
                            } 
                            if (page.ClientSupportsJavaScript || !formOnSubmit.ToLower(CultureInfo.CurrentCulture).Contains("javascript")) {
                                page.ClientScript.RegisterOnSubmitStatement(typeof(HtmlForm), "OnSubmitScript", formOnSubmit); 
                            }
                            Attributes.Remove("onsubmit");
                        }
                    } 

                    // Don't render the on submit if it contains javascript and the page doesn't support it 
                    if (page.ClientSupportsJavaScript || !onSubmit.ToLower(CultureInfo.CurrentCulture).Contains("javascript")) { 
                        if (enableLegacyRendering) {
                            writer.WriteAttribute("language", "javascript", false); 
                        }
                        writer.WriteAttribute("onsubmit", onSubmit);
                    }
                } 

                if ((page.RequestInternal != null) && 
                    (page.RequestInternal.Browser.EcmaScriptVersion.Major > 0) && 
                    (page.RequestInternal.Browser.W3CDomVersion.Major > 0)) {
                    if (DefaultButton.Length > 0) { 
                        Control c = FindControl(DefaultButton);

                        // Find control from the page if it's a hierarchical ID.
                        if (c == null && Page != null) { 
                            char[] findControlSeparators = { ID_SEPARATOR, LEGACY_ID_SEPARATOR };
                            if (DefaultButton.IndexOfAny(findControlSeparators) != -1) { 
                                c = Page.FindControl(DefaultButton); 
                            }
                        } 

                        if (c is IButtonControl) {
                            page.ClientScript.RegisterDefaultButtonScript(c, writer, false /* UseAddAttribute */);
                        } 
                        else {
                            throw new InvalidOperationException(SR.GetString(SR.HtmlForm_OnlyIButtonControlCanBeDefaultButton, ID)); 
                        } 
                    }
                } 
            }


            // We always want the form to have an id on the client 
            // base.RenderAttributes takes care of actually rendering it.
            EnsureID(); 
 
            base.RenderAttributes(writer);
        } 


        /// 
        ///  
        /// 
        protected internal override void RenderChildren(HtmlTextWriter writer) { 
            // We need to register the script here since other controls might register 
            // for focus during PreRender
            Page page = Page; 
            if (page != null) {
                page.OnFormRender();
                page.BeginFormRender(writer, UniqueID);
            } 

            // DevDiv Bugs 154630: move custom hidden fields to the begining of the form 
            HttpWriter httpWriter = writer.InnerWriter as HttpWriter; 
            if (page != null && httpWriter != null && RuntimeConfig.GetConfig(Context).Pages.RenderAllHiddenFieldsAtTopOfForm) {
                // If the response is flushed or cleared during render, we won't be able 
                // to move the hidden fields.  Set HasBeenClearedRecently to false and
                // then check again when we're ready to move the fields.
                httpWriter.HasBeenClearedRecently = false;
 
                // Remember the index where the form begins
                int formBeginIndex = httpWriter.GetResponseBufferCountAfterFlush(); 
 
                base.RenderChildren(writer);
 
                // Remember the index where the custom hidden fields begin
                int fieldsBeginIndex = httpWriter.GetResponseBufferCountAfterFlush();

                page.EndFormRenderHiddenFields(writer, UniqueID); 

                // we can only move the hidden fields if the response has not been flushed or cleared 
                if (!httpWriter.HasBeenClearedRecently) { 
                    int fieldsEndIndex = httpWriter.GetResponseBufferCountAfterFlush();
                    httpWriter.MoveResponseBufferRangeForward(fieldsBeginIndex, fieldsEndIndex - fieldsBeginIndex, formBeginIndex); 
                }

                page.EndFormRenderArrayAndExpandoAttribute(writer, UniqueID);
                page.EndFormRenderPostBackAndWebFormsScript(writer, UniqueID); 
                page.OnFormPostRender(writer);
            } 
            else { 
                base.RenderChildren(writer);
 
                if (page != null) {
                    page.EndFormRender(writer, UniqueID);
                    page.OnFormPostRender(writer);
                } 
            }
        } 
 
        public override void RenderControl(HtmlTextWriter writer) {
            if (DesignMode) { 
                // User Control Designer scenario
                base.RenderChildren(writer);
            }
            else { 
                base.RenderControl(writer);
            } 
        } 

        protected override ControlCollection CreateControlCollection() { 
            return new ControlCollection(this, 100, 2);
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK