[Solved] ItemIndexHierarchical Removal Problem

[Andrew]

Hi

I have 2 questions/problems to ask: 

1) I have a Hierarchical Grid that drills down 3 levels and I am currently using a snippet of code found on the forum (see below) that allows me to keep open any children, grandchildren within the Hierarchical Grid on rebind. Although it only works for 2 levels , is it possible for this to be modified for, say, an infinite amount ot children, grandchildren and so on...

        protected void RadGrid1_DataBound(object sender, EventArgs e)
        {
            //Expand all items using our custom storage
            string[] indexes = new string[this.ExpandedStates.Keys.Count];

            this.ExpandedStates.Keys.CopyTo(indexes, 0);

            ArrayList arr = new ArrayList(indexes);
            //Sort so we can guarantee that a parent item is expanded before any of
            //its children
            arr.Sort();

            foreach (string key in arr)
            {
                bool value = (bool)this.ExpandedStates[key];
                if (value)
                {
                    RadGrid1.Items[key].Expanded = true;
                }
            }

            //Select all items using our custom storage
            indexes = new string[this.SelectedStates.Keys.Count];
            this.SelectedStates.Keys.CopyTo(indexes, 0);

            arr = new ArrayList(indexes);
            //Sort to ensure that a parent item is selected before any of its children
            arr.Sort();

            foreach (string key in arr)
            {
                bool value = (bool)this.SelectedStates[key];
                if (value)
                {
                    RadGrid1.Items[key].Selected = true;
                }
            }
        }

        //Save/load expanded states Hash from the session
        //this can also be implemented in the ViewState
        private Hashtable ExpandedStates
        {
            get
            {
                if (this._visitsExpandedState == null)
                {
                    _visitsExpandedState = this.Session["_visitsExpandedState"] as Hashtable;
                    if (_visitsExpandedState == null)
                    {
                        _visitsExpandedState = new Hashtable();
                        this.Session["_visitsExpandedState"] = _visitsExpandedState;
                    }
                }

                return this._visitsExpandedState;
            }
        }

        //Clear the state for all expanded children if a parent item is collapsed
        private void ClearExpandedChildren(string parentHierarchicalIndex)
        {
            string[] indexes = new string[this.ExpandedStates.Keys.Count];

            this.ExpandedStates.Keys.CopyTo(indexes, 0);
            foreach (string index in indexes)
            {
                //all indexes of child items
                if (index.StartsWith(parentHierarchicalIndex + "_") ||
                    index.StartsWith(parentHierarchicalIndex + ":"))
                {
                    this.ExpandedStates.Remove(index);
                }
            }
        }

        //Save/load selected states Hash from the session
        //this can also be implemented in the ViewState
        private Hashtable SelectedStates
        {
            get
            {
                if (this._selectedState == null)
                {
                    _selectedState = this.Session["_selectedState"] as Hashtable;
                    if (_selectedState == null)
                    {
                        _selectedState = new Hashtable();
                        this.Session["_selectedState"] = _selectedState;
                    }
                }

                return this._selectedState;
            }
        }

        protected void RadGrid1_ItemCommand(object source, GridCommandEventArgs e)
        {
            //save the expanded/selected state in the session
            if (e.CommandName == RadGrid.ExpandCollapseCommandName)
            {
                //Is the item about to be expanded or collapsed
                if (!e.Item.Expanded)
                {
                    //Save its unique index among all the items in the hierarchy
                    this.ExpandedStates[e.Item.ItemIndexHierarchical] = true;
                }
                else //collapsed
                {
                    this.ExpandedStates.Remove(e.Item.ItemIndexHierarchical);
                    this.ClearExpandedChildren(e.Item.ItemIndexHierarchical);
                }
            }
            //Is the item about to be selected
            else if (e.CommandName == RadGrid.SelectCommandName)
            {
                //Save its unique index among all the items in the hierarchy
                this.SelectedStates[e.Item.ItemIndexHierarchical] = true;
            }
            //Is the item about to be deselected
            else if (e.CommandName == RadGrid.DeselectCommandName)
            {
                this.SelectedStates.Remove(e.Item.ItemIndexHierarchical);
            }
        }

2) Within the same Hierarchical Grid I am allowing users to remove either children and grandchildren , and when doing so in order for the ribind to reopen any previously open levels, i need to remove the ExpandedStates.Keys of the item being deleted, but i am having trouble doing so, and this causes my rebind to error due to it finding an expandedState Key that no longer exists.

Can you help?

Thanks in advance

[Tsvetoslav]

Hello Greg,

I have prepared a small sample that demonstrates this scenario using both session and cookies to cache the expanded items' keys.

All the best,
Tsvetoslav
the Telerik team

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[Andrew]

Hi

That demo you sent me really helped, its all working as required now.

Thanks for all your help.