Repeater.cs source code in C# .NET

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Code:

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

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

namespace System.Web.UI.WebControls { 
    using System; 
    using System.Collections;
    using System.ComponentModel; 
    using System.ComponentModel.Design;
    using System.Web;
    using System.Web.UI;
    using System.Web.Util; 

    ///  
    /// Defines the properties, methods, and events of a  class. 
    /// 
    [ 
    DefaultEvent("ItemCommand"),
    DefaultProperty("DataSource"),
    Designer("System.Web.UI.Design.WebControls.RepeaterDesigner, " + AssemblyRef.SystemDesign),
    ParseChildren(true), 
    PersistChildren(false)
    ] 
    public class Repeater : Control, INamingContainer { 

        private static readonly object EventItemCreated = new object(); 
        private static readonly object EventItemDataBound = new object();
        private static readonly object EventItemCommand = new object();

        internal const string ItemCountViewStateKey = "_!ItemCount"; 

        private object dataSource; 
        private ITemplate headerTemplate; 
        private ITemplate footerTemplate;
        private ITemplate itemTemplate; 
        private ITemplate alternatingItemTemplate;
        private ITemplate separatorTemplate;

        private ArrayList itemsArray; 
        private RepeaterItemCollection itemsCollection;
 
        private bool _requiresDataBinding; 
        private bool _inited;
        private bool _throwOnDataPropertyChange; 

        private DataSourceView _currentView;
        private bool _currentViewIsFromDataSourceID;
        private bool _currentViewValid; 
        private DataSourceSelectArguments _arguments;
        private bool _pagePreLoadFired; 
 

        ///  
        /// Initializes a new instance of the  class.
        /// 
        public Repeater() {
        } 

 
        ///  
        /// Gets or sets the  that defines how alternating (even-indexed) items
        ///    are rendered.  
        /// 
        [
            Browsable(false),
            DefaultValue(null), 
            PersistenceMode(PersistenceMode.InnerProperty),
            TemplateContainer(typeof(RepeaterItem)), 
            WebSysDescription(SR.Repeater_AlternatingItemTemplate) 
        ]
        public virtual ITemplate AlternatingItemTemplate { 
            get {
                return alternatingItemTemplate;
            }
            set { 
                alternatingItemTemplate = value;
            } 
        } 

 
        public override ControlCollection Controls {
            get {
                EnsureChildControls();
                return base.Controls; 
            }
        } 
 

        ///  
        ///    [To be supplied.]
        /// 
        [
        DefaultValue(""), 
        WebCategory("Data"),
        WebSysDescription(SR.Repeater_DataMember) 
        ] 
        public virtual string DataMember {
            get { 
                object o = ViewState["DataMember"];
                if (o != null)
                    return (string)o;
                return String.Empty; 
            }
            set { 
                ViewState["DataMember"] = value; 
                OnDataPropertyChanged();
            } 
        }


        ///  
        ///     Gets or sets the data source that provides data for
        ///       populating the list. 
        ///  
        [
            Bindable(true), 
            WebCategory("Data"),
            DefaultValue(null),
            DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
            WebSysDescription(SR.BaseDataBoundControl_DataSource) 
        ]
        public virtual object DataSource { 
            get { 
                return dataSource;
            } 
            set {
                if ((value == null) || (value is IListSource) || (value is IEnumerable)) {
                    dataSource = value;
                    OnDataPropertyChanged(); 
                }
                else { 
                    throw new ArgumentException(SR.GetString(SR.Invalid_DataSource_Type, ID)); 
                }
            } 
        }


        ///  
        /// The ID of the DataControl that this control should use to retrieve
        /// its data source. When the control is bound to a DataControl, it 
        /// can retrieve a data source instance on-demand, and thereby attempt 
        /// to work in auto-DataBind mode.
        ///  
        [
        DefaultValue(""),
        IDReferenceProperty(typeof(DataSourceControl)),
        WebCategory("Data"), 
        WebSysDescription(SR.BaseDataBoundControl_DataSourceID)
        ] 
        public virtual string DataSourceID { 
            get {
                object o = ViewState["DataSourceID"]; 
                if (o != null) {
                    return (string)o;
                }
                return String.Empty; 
            }
            set { 
                ViewState["DataSourceID"] = value; 
                OnDataPropertyChanged();
            } 
        }

        /// 
        ///    Gets and sets a value indicating whether theme is enabled. 
        /// 
        [ 
        Browsable(true) 
        ]
        public override bool EnableTheming { 
            get {
                return base.EnableTheming;
            }
            set { 
                base.EnableTheming = value;
            } 
        } 

 
        /// 
        /// Gets or sets the  that defines how the control footer is
        ///    rendered. 
        ///  
        [
            Browsable(false), 
            DefaultValue(null), 
            PersistenceMode(PersistenceMode.InnerProperty),
            TemplateContainer(typeof(RepeaterItem)), 
            WebSysDescription(SR.Repeater_FooterTemplate)
        ]
        public virtual ITemplate FooterTemplate {
            get { 
                return footerTemplate;
            } 
            set { 
                footerTemplate = value;
            } 
        }


        ///  
        /// Gets or sets the  that defines how the control header is rendered. 
        ///  
        [ 
            Browsable(false),
            DefaultValue(null), 
            PersistenceMode(PersistenceMode.InnerProperty),
            TemplateContainer(typeof(RepeaterItem)),
            WebSysDescription(SR.WebControl_HeaderTemplate)
        ] 
        public virtual ITemplate HeaderTemplate {
            get { 
                return headerTemplate; 
            }
            set { 
                headerTemplate = value;
            }
        }
 

        protected bool Initialized { 
            get { 
                return _inited;
            } 
        }


        protected bool IsBoundUsingDataSourceID { 
            get {
                return (DataSourceID.Length > 0); 
            } 
        }
 

        /// 
        ///    Gets the  collection.
        ///  
        [
            Browsable(false), 
            DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
            WebSysDescription(SR.Repeater_Items)
        ] 
        public virtual RepeaterItemCollection Items {
            get {
                if (itemsCollection == null) {
                    if (itemsArray == null) { 
                        EnsureChildControls();
                    } 
                    itemsCollection = new RepeaterItemCollection(itemsArray); 
                }
                return itemsCollection; 
            }
        }

 
        /// 
        /// Gets or sets the  that defines how items are rendered.  
        ///  
        [
            Browsable(false), 
            DefaultValue(null),
            PersistenceMode(PersistenceMode.InnerProperty),
            TemplateContainer(typeof(RepeaterItem)),
            WebSysDescription(SR.Repeater_ItemTemplate) 
        ]
        public virtual ITemplate ItemTemplate { 
            get { 
                return itemTemplate;
            } 
            set {
                itemTemplate = value;
            }
        } 

 
        protected bool RequiresDataBinding { 
            get {
                return _requiresDataBinding; 
            }
            set {
                _requiresDataBinding = value;
            } 
        }
 
        protected DataSourceSelectArguments SelectArguments { 
            get {
                if (_arguments == null) { 
                    _arguments = CreateDataSourceSelectArguments();
                }
                return _arguments;
            } 
        }
 
 
        /// 
        /// Gets or sets the  that defines how separators 
        ///    in between items are rendered.
        /// 
        [
            Browsable(false), 
            DefaultValue(null),
            PersistenceMode(PersistenceMode.InnerProperty), 
            TemplateContainer(typeof(RepeaterItem)), 
            WebSysDescription(SR.Repeater_SeparatorTemplate)
        ] 
        public virtual ITemplate SeparatorTemplate {
            get {
                return separatorTemplate;
            } 
            set {
                separatorTemplate = value; 
            } 
        }
 


        /// 
        /// Occurs when a button is clicked within the  control tree. 
        /// 
       [ 
        WebCategory("Action"), 
        WebSysDescription(SR.Repeater_OnItemCommand)
        ] 
        public event RepeaterCommandEventHandler ItemCommand {
            add {
                Events.AddHandler(EventItemCommand, value);
            } 
            remove {
                Events.RemoveHandler(EventItemCommand, value); 
            } 
        }
 


        /// 
        ///  Occurs when an item is created within the  control tree. 
        /// 
        [ 
        WebCategory("Behavior"), 
        WebSysDescription(SR.DataControls_OnItemCreated)
        ] 
        public event RepeaterItemEventHandler ItemCreated {
            add {
                Events.AddHandler(EventItemCreated, value);
            } 
            remove {
                Events.RemoveHandler(EventItemCreated, value); 
            } 
        }
 

        /// 
        /// Occurs when an item is databound within a  control tree.
        ///  
        [
        WebCategory("Behavior"), 
        WebSysDescription(SR.DataControls_OnItemDataBound) 
        ]
        public event RepeaterItemEventHandler ItemDataBound { 
            add {
                Events.AddHandler(EventItemDataBound, value);
            }
            remove { 
                Events.RemoveHandler(EventItemDataBound, value);
            } 
        } 

 
        /// 
        /// Connects this data bound control to the appropriate DataSourceView
        /// and hooks up the appropriate event listener for the
        /// DataSourceViewChanged event. The return value is the new view (if 
        /// any) that was connected to. An exception is thrown if there is
        /// a problem finding the requested view or data source. 
        ///  
        private DataSourceView ConnectToDataSourceView() {
            if (_currentViewValid && !DesignMode) { 
                // If the current view is correct, there is no need to reconnect
                return _currentView;
            }
 
            // Disconnect from old view, if necessary
            if ((_currentView != null) && (_currentViewIsFromDataSourceID)) { 
                // We only care about this event if we are bound through the DataSourceID property 
                _currentView.DataSourceViewChanged -= new EventHandler(OnDataSourceViewChanged);
            } 

            // Connect to new view
            IDataSource ds = null;
            string dataSourceID = DataSourceID; 

            if (dataSourceID.Length != 0) { 
                // Try to find a DataSource control with the ID specified in DataSourceID 
                Control control = DataBoundControlHelper.FindControl(this, dataSourceID);
                if (control == null) { 
                    throw new HttpException(SR.GetString(SR.DataControl_DataSourceDoesntExist, ID, dataSourceID));
                }
                ds = control as IDataSource;
                if (ds == null) { 
                    throw new HttpException(SR.GetString(SR.DataControl_DataSourceIDMustBeDataControl, ID, dataSourceID));
                } 
            } 

            if (ds == null) { 
                // DataSource control was not found, construct a temporary data source to wrap the data
                ds = new ReadOnlyDataSource(DataSource, DataMember);
            }
            else { 
                // Ensure that both DataSourceID as well as DataSource are not set at the same time
                if (DataSource != null) { 
                    throw new InvalidOperationException(SR.GetString(SR.DataControl_MultipleDataSources, ID)); 
                }
            } 

            // IDataSource was found, extract the appropriate view and return it
            DataSourceView newView = ds.GetView(DataMember);
            if (newView == null) { 
                throw new InvalidOperationException(SR.GetString(SR.DataControl_ViewNotFound, ID));
            } 
 
            _currentViewIsFromDataSourceID = IsBoundUsingDataSourceID;
            _currentView = newView; 
            if ((_currentView != null) && (_currentViewIsFromDataSourceID)) {
                // We only care about this event if we are bound through the DataSourceID property
                _currentView.DataSourceViewChanged += new EventHandler(OnDataSourceViewChanged);
            } 
            _currentViewValid = true;
 
            return _currentView; 
        }
 

        /// 
        /// 
        protected internal override void CreateChildControls() { 
            Controls.Clear();
 
            if (ViewState[ItemCountViewStateKey] != null) { 
                // create the control hierarchy using the view state (and
                // not the datasource) 
                CreateControlHierarchy(false);
            }
            else {
                itemsArray = new ArrayList(); 
            }
            ClearChildViewState(); 
        } 

 

        /// 
        ///    A protected method. Creates a control
        ///    hierarchy, with or without the data source as specified. 
        /// 
        protected virtual void CreateControlHierarchy(bool useDataSource) { 
            IEnumerable dataSource = null; 
            int count = -1;
 
            if (itemsArray != null) {
                itemsArray.Clear();
            }
            else { 
                itemsArray = new ArrayList();
            } 
 
            if (useDataSource == false) {
                // ViewState must have a non-null value for ItemCount because we check for 
                // this in CreateChildControls
                count = (int)ViewState[ItemCountViewStateKey];
                if (count != -1) {
                    dataSource = new DummyDataSource(count); 
                    itemsArray.Capacity = count;
                } 
            } 
            else {
                dataSource = GetData(); 

                ICollection collection = dataSource as ICollection;
                if (collection != null) {
                    itemsArray.Capacity = collection.Count; 
                }
            } 
 
            if (dataSource != null) {
                RepeaterItem item; 
                ListItemType itemType;
                int index = 0;

                bool hasSeparators = (separatorTemplate != null); 
                count = 0;
 
                if (headerTemplate != null) { 
                    CreateItem(-1, ListItemType.Header, useDataSource, null);
                } 

                foreach (object dataItem in dataSource) {
                    // rather than creating separators after the item, we create the separator
                    // for the previous item in all iterations of this loop. 
                    // this is so that we don't create a separator for the last item
                    if (hasSeparators && (count > 0)) { 
                        CreateItem(index - 1, ListItemType.Separator, useDataSource, null); 
                    }
 
                    itemType = (index % 2 == 0) ? ListItemType.Item : ListItemType.AlternatingItem;
                    item = CreateItem(index, itemType, useDataSource, dataItem);
                    itemsArray.Add(item);
 
                    count++;
                    index++; 
                } 

                if (footerTemplate != null) { 
                    CreateItem(-1, ListItemType.Footer, useDataSource, null);
                }
            }
 
            if (useDataSource) {
                // save the number of items contained in the repeater for use in round-trips 
                ViewState[ItemCountViewStateKey] = ((dataSource != null) ? count : -1); 
            }
        } 

        protected virtual DataSourceSelectArguments CreateDataSourceSelectArguments() {
            return DataSourceSelectArguments.Empty;
        } 

 
        ///  
        /// 
        private RepeaterItem CreateItem(int itemIndex, ListItemType itemType, bool dataBind, object dataItem) { 
            RepeaterItem item = CreateItem(itemIndex, itemType);
            RepeaterItemEventArgs e = new RepeaterItemEventArgs(item);

            InitializeItem(item); 
            if (dataBind) {
                item.DataItem = dataItem; 
            } 
            OnItemCreated(e);
            Controls.Add(item); 

            if (dataBind) {
                item.DataBind();
                OnItemDataBound(e); 

                item.DataItem = null; 
            } 

            return item; 
        }


        ///  
        /// A protected method. Creates a  with the specified item type and
        ///    location within the . 
        ///  
        protected virtual RepeaterItem CreateItem(int itemIndex, ListItemType itemType) {
            return new RepeaterItem(itemIndex, itemType); 
        }


        ///  
        /// 
        ///  
        public override void DataBind() { 
            // Don't databind to a data source control when the control is in the designer but not top-level
            if (IsBoundUsingDataSourceID && DesignMode && (Site == null)) { 
                return;
            }

            // do our own databinding 
            RequiresDataBinding = false;
            OnDataBinding(EventArgs.Empty); 
 
            // contained items will be databound after they have been created,
            // so we don't want to walk the hierarchy here. 
        }


        protected void EnsureDataBound() { 
            try {
                _throwOnDataPropertyChange = true; 
                if (RequiresDataBinding && DataSourceID.Length > 0) { 
                    DataBind();
                } 
            }
            finally {
                _throwOnDataPropertyChange = false;
            } 
        }
 
 
        /// 
        /// Returns an IEnumerable that is the DataSource, which either came 
        /// from the DataSource property or from the control bound via the
        /// DataSourceID property.
        /// 
        protected virtual IEnumerable GetData() { 
            DataSourceView view = ConnectToDataSourceView();
 
            Debug.Assert(_currentViewValid); 

            if (view != null) { 
                return view.ExecuteSelect(SelectArguments);
            }
            return null;
        } 

 
        ///  
        /// A protected method. Populates iteratively the specified  with a
        ///    sub-hierarchy of child controls. 
        /// 
        protected virtual void InitializeItem(RepeaterItem item) {
            ITemplate contentTemplate = null;
 
            switch (item.ItemType) {
                case ListItemType.Header: 
                    contentTemplate = headerTemplate; 
                    break;
 
                case ListItemType.Footer:
                    contentTemplate = footerTemplate;
                    break;
 
                case ListItemType.Item:
                    contentTemplate = itemTemplate; 
                    break; 

                case ListItemType.AlternatingItem: 
                    contentTemplate = alternatingItemTemplate;
                    if (contentTemplate == null)
                        goto case ListItemType.Item;
                    break; 

                case ListItemType.Separator: 
                    contentTemplate = separatorTemplate; 
                    break;
            } 

            if (contentTemplate != null) {
                contentTemplate.InstantiateIn(item);
            } 
        }
 
 
        /// 
        ///  
        /// 
        protected override bool OnBubbleEvent(object sender, EventArgs e) {
            bool handled = false;
 
            if (e is RepeaterCommandEventArgs) {
                OnItemCommand((RepeaterCommandEventArgs)e); 
                handled = true; 
            }
 
            return handled;
        }

 
        /// 
        ///  
        /// A protected method. Raises the  event. 
        /// 
        protected override void OnDataBinding(EventArgs e) { 
            base.OnDataBinding(e);

            // reset the control state
            Controls.Clear(); 
            ClearChildViewState();
 
            // and then create the control hierarchy using the datasource 
            CreateControlHierarchy(true);
            ChildControlsCreated = true; 
        }


        ///  
        ///  This method is called when DataMember, DataSource, or DataSourceID is changed.
        ///  
        protected virtual void OnDataPropertyChanged() { 
            if (_throwOnDataPropertyChange) {
                throw new HttpException(SR.GetString(SR.DataBoundControl_InvalidDataPropertyChange, ID)); 
            }

            if (_inited) {
                RequiresDataBinding = true; 
            }
            _currentViewValid = false; 
        } 

 
        protected virtual void OnDataSourceViewChanged(object sender, EventArgs e) {
            RequiresDataBinding = true;
        }
 

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

            if (Page != null) { 
                Page.PreLoad += new EventHandler(this.OnPagePreLoad);
                if (!IsViewStateEnabled && Page.IsPostBack) {
                    RequiresDataBinding = true;
                } 
            }
        } 
 

        ///  
        /// A protected method. Raises the  event.
        /// 
        protected virtual void OnItemCommand(RepeaterCommandEventArgs e) {
            RepeaterCommandEventHandler onItemCommandHandler = (RepeaterCommandEventHandler)Events[EventItemCommand]; 
            if (onItemCommandHandler != null) onItemCommandHandler(this, e);
        } 
 
        /// 
        /// A protected method. Raises the  event. 
        /// 
        protected virtual void OnItemCreated(RepeaterItemEventArgs e) {
            RepeaterItemEventHandler onItemCreatedHandler = (RepeaterItemEventHandler)Events[EventItemCreated];
            if (onItemCreatedHandler != null) onItemCreatedHandler(this, e); 
        }
 
 
        /// 
        /// A protected method. Raises the  
        /// event.
        /// 
        protected virtual void OnItemDataBound(RepeaterItemEventArgs e) {
            RepeaterItemEventHandler onItemDataBoundHandler = (RepeaterItemEventHandler)Events[EventItemDataBound]; 
            if (onItemDataBoundHandler != null) onItemDataBoundHandler(this, e);
        } 
 

        protected internal override void OnLoad(EventArgs e) { 
            _inited = true; // just in case we were added to the page after PreLoad
            ConnectToDataSourceView();
            if (Page != null && !_pagePreLoadFired && ViewState[ItemCountViewStateKey] == null) {
                // If the control was added after PagePreLoad, we still need to databind it because it missed its 
                // first change in PagePreLoad.  If this control was created by a call to a parent control's DataBind
                // in Page_Load (with is relatively common), this control will already have been databound even 
                // though pagePreLoad never fired and the page isn't a postback. 
                if (!Page.IsPostBack) {
                    RequiresDataBinding = true; 
                }

                // If the control was added to the page after page.PreLoad, we'll never get the event and we'll
                // never databind the control.  So if we're catching up and Load happens but PreLoad never happened, 
                // call DataBind.  This may make the control get databound twice if the user called DataBind on the control
                // directly in Page.OnLoad, but better to bind twice than never to bind at all. 
                else if (IsViewStateEnabled) { 
                    RequiresDataBinding = true;
                } 
            }

            base.OnLoad(e);
        } 

        private void OnPagePreLoad(object sender, EventArgs e) { 
            _inited = true; 

            if (Page != null) { 
                Page.PreLoad -= new EventHandler(this.OnPagePreLoad);

                // Setting RequiresDataBinding to true in OnLoad is too late because the OnLoad page event
                // happens before the control.OnLoad method gets called.  So a page_load handler on the page 
                // that calls DataBind won't prevent DataBind from getting called again in PreRender.
                if (!Page.IsPostBack) { 
                    RequiresDataBinding = true; 
                }
 
                // If this is a postback and viewstate is enabled, but we have never bound the control
                // before, it is probably because its visibility was changed in the postback.  In this
                // case, we need to bind the control or it will never appear.  This is a common scenario
                // for Wizard and MultiView. 
                if (Page.IsPostBack && IsViewStateEnabled && ViewState[ItemCountViewStateKey] == null) {
                    RequiresDataBinding = true; 
                } 
            _pagePreLoadFired = true;
 
            }
        }

 
        protected internal override void OnPreRender(EventArgs e) {
            EnsureDataBound(); 
            base.OnPreRender(e); 
        }
    } 
}


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

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