HierarGrid - A hierarchical DataGrid that displays master-detail relations

Problem:

The ASP.NET DataGrid is a popular control to display data in a table form with editing, paging and sorting capabilites.
However it is only suitable to display single DataTables - there is no support for parent-child relations.

Goal:

To create a control that provides the standard DataGrid functionality and at the same time can display parent-child relations using templates to display the child elements.

Procedure:

I have created a custom control called HierarGrid that derives from the DataGrid and a custom DataGridColumn called HierarColumn.

The HierarGrid takes a DataSet that contains relations between the tables.

While iterating over the parent table it checks the related tables for child rows and if one is found it dynamically loads a template for the child row(s).

The template is rendered invisibly into the custom HierarColumn and when the user clicks the plus icon, the template content is copied via JavaScript into a newly created TableRow.

Download (V2.2):

• The sourcecode is available in C# as a VS.NET 2002 project.

• A ready-to-use assembly (including help file).

How to get started:

• A step-by-step tutorial that explains the usage of the HierarGrid is available on ASPAlliance

• The demo that is mentioned in the article shows the usage of this control.
  Sourcecode for the Demo (C#) or Sourcecode for the Demo (VB)

• A really advanced sample application with documentation that shows filtering, sorting, paging, exporting with the HierarGrid was written by Nigel Parham. Please note that it is provided as-is like all downloads on this site.

• A simple demo that shows editing in the HierarGrid.

• And finally some snapshots showing real-life samples of the HierarGrid: Snapshot 1    Snapshot 2    Snapshot 3

History:

Bugfix: Under some conditions, UserControls still could not be reloaded when the application is configured as a website

Bugfix: UserControls could not be reloaded when the application is configured as a website (as opposed to virt.dir.) (thanks to Keith Culpepper)

Bugfix: fixed regression if ShowHeader=false and AllowPaging=false, colspan is wrong (thanks to Stuart Hilbert)

Bugfix: resolved compatibility issue with ASP.NET 2.0

Feature: TemplateDataMode.RunTime makes it possible to choose between SingleRow and Table for each relation at runtime (thanks to Tom Schmidt)

Feature: child templates are displayed for rows in selected state (thanks to Patrick Martin)

Bugfix: state of Checkboxes in child templates is now correctly preserved (thanks to Paolo Falabella)

Bugfix: corrected Mozilla DHTML incompatibilities (thanks to David Tétreault)

Bugfix: corrected problem with non-unique IDs that were generated for "ChildTemplate" panel in a DataMode=Table HierarGrid

Bugfix: child templates were inserted into first column when PagerStyle was set to "Top"

Bugfix: resetting the DataItem after inserting the child templates for further custom processing

Bugfix: copying selected state for <select> tags

Feature: nested HierarGrids now possibly with more than 3 levels (thanks to Matt Petteys)

Bugfix: RowExpanded[x] = false was ignored

Bugfix: excluded RowExpanded property from Designer's Property view

Bugfix: changed Namespace for internal DynamicControlsPlaceholder to avoid conflicts when using both HierarGrid and DCP in one solution (thanks to Matt Bornstein)

Feature: keeps rowstate (expanded/collapsed) between postbacks

Feature: property "RowExpanded" to initially expand rows

Bugfix: HierarColumn not added to Columns collection

Bugfix: Exception with DataViews as DataSource and TemplateDataMode=Table

Bugfix: When TemplateDataMode=Table and DataSet.EnforceContraints=true an exception occured

Bugfix: Designer declaration corrected

Bugfix: corrected JavaScript to allow ShowHeader=False for the Grid

Bugfix: problem solved when TemplateDataMode=Table and DataSource was set to DataSet instead of DataTable

Feature: added support for Netscape and Opera

Feature: added support for nested HierarGrids
Bugfix: Exception when calling DataBind twice within one Request
Bugfix: Wrong PostData for TextBoxes in a child template

Initial version

Known Problems:

• DataBind is called automatically for child templates (by design)
• if the row order or the page index changes between postbacks a wrong row may be expanded as the row state is stored by index. This issue is by design and can be worked around by calling HG.RowExpanded.CollapseAll()
• UserControls with "_" in the filename:
  Unfortunatley, the DCP (that is used internally) cannot recreate UserControls whose filename contains "_" and other special characters. Furthermore, it doesn't work if a custom ClassName is given in the ASCX file.

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