Grid Grouping Support

Essential Grid offers flexible support for grouping both flat and hierarchical datasources. It supports expressions fields, filters, multi-column sorting, grouping, nested tables/hierarchies, and custom summaries.

Essential Grid's GridGroupingControl can quickly provide custom views for non-nested data tables. Users can filter, group, sort and summarize data with summary rows. You can also add custom formula columns that can be used in grouping and summaries. The grouping architecture is flexible and can be used with any IList object with items having public properties.

Users can group and sort multiple columns. When edited, affected group, sort or filter will be automatically adjusted.

It is possible to customize the layout of groups. You can add a Custom Section for each group and display the Summary Section above the details.

Any ADO.NET dataset can be displayed without any configuration using the Grid Grouping Control. The grid will automatically extract all column and relational information from the dataset and display them.

The GridGroupingControl supports data with hierarchical relationships and nested tables. Each record in a hierarchical grid can have multiple nested relations. Users may expand the record to show the nested relations. Each nested table can be expanded individually by clicking on the plus-minus button next to the caption text. Changes to any data element automatically updates the grid and positions the modified records relatively. Users may add new rows at any level.

Foreign key relations can be defined to control the display values in Grid Grouping Control. A column named CompanyIDcan be replaced with CompanyName in a transparent manner. Multi-column drop-downs listing choices can also be edited and displayed.

The Grid Grouping Control lets users add one or more summary rows to each group. Record modification works in complete synchronization with summaries. The calculation of summary values is fast with just O(log2 n) operations ('n' being the number of records in the table)due to the use of balanced tree structures in the grouping engine. Grouping has several built-in functions such as:

* Int32Aggregate, DoubleAggregate (Count, Min, Max, Sum)
* StringAggregate (MaxLength, Count)
* Count
* DistinctCount (Count, Values array)
* Vector (Values)
* DoubleVector (statistical methods: Median, Min, Max, 25% Quartile, 75% Quartile)

The grouping engine supports summaries that operate on vectors such as Distinct Count, Median, 25% and 75% Quartile. Users can also add custom summaries like weighted averages.

Summary can be included in the group caption rows and the display sorted by summary values.

A subset of records that satisfy user defined criteria can be extracted and displayed using Filters. A Filter Bar can be included in the grid to filter by selected-option from a drop-down list. It is also possible to adopt a custom filter dialog by customizing the 'Custom' option in the filter-bar cell's drop-down.

Dynamic Filter
This feature replaces the default filter bar with a custom filter bar that displays filtered results as you type each and every character. It has an user-friendly UI where in you can apply any compare operator with a single button click.

Expression field facilitates the inclusion of a column with formula expression. The grouping engine comes with its own extensible formula engine for this purpose. Expression fields can be used in records just like a regular field. Users can calculate summary, group, sort or create filters based on expression fields.

The winning and losing columns have been created using expression fields in the illustration below:

Grid contents can be sorted based on values of any column. You can perform custom sorting on a column by providing an IComparer object for that column.

The sorting can be applied to multiple columns and the sort order displayed in column headers.

Each hierarchical level can be grouped by the columns of its table. This feature is illustrated below:

Preview Rows can be enabled to display memo fields or notes for a given group or record. It is possible to add a preview section for each group or record.

Additional header rows that span across visible grid columns in a stacked fashion can be created for the Grid Grouping Control. Columns can be grouped under each header row and these grouped columns get re-arranged by grouping headers. Complete drag-drop support is available for these header rows.

The appearance of the grid's grouping elements can be customized using base styles. Each element in the grouping display is associated with a base style that defines its appearance.

The API provides numerous options to customize cell ranges and let you specify custom covering of individual cells across multiple cells. Covering an image field cell across all records in it's category is illustrated belo

when saving a record, if constraints are violated, the affected column is displayed with a red marker. Hovering the mouse pointer over the error indicator will display a ToolTip and provide information explaining the constraint violation.

The appearance of the Grid Grouping Control can be enhanced by applying one of the available MS Office 2003 and 2007 styles.

An Add New Record row option can be displayed at the top or bottom of the table. Alternatively, Add New Record can be displayed for each group.

The Add New Record works much like the current record. Users save changes with the ENTER key, cancel changes with the ESC key or release the record. The record will be sorted into the existing recordset and the record's parent group will be expanded.

Constraints are checked while saving the record. The group's category will be assigned as default values into the Add New Record when the user begins typing into the record for a group.

When a user changes the foreign key value of a record in a nested table, the Grid Grouping Control will automatically move the record to its new parent table and scroll the table into view.

Changing the 'SupplierID' of a Product moves it to its respective Supplier group as illustrated below:

When the record column used to categorize the table into groups is changed, the grid will automatically insert the record into the new group category and scroll the group into view. If necessary, a new group is inserted and/or the old group is removed from the table. changin the 'Country' of one record is illustrated below:

After the change, the record has been inserted under the new group and scrolled into view.

The end user can customize the grid display by performing a drag-and-drop of column header cells.

When the header cell is dropped on a different column, the visible order of columns will be rearranged.

When the cell is dropped on the group drop area, the table will be grouped by the column.

A record can span multiple rows or columns. In the illustration below, the 'ID' and 'Photo' columns include records that occupy multiple rows and the 'Address' Column includes rows that occupy multiple columns:

The Grid Grouping Control uses the TAB key to navigate to various cells in the Grid. Alternatively, any other key can also be utilized for this purpose.

Serialization is the process of saving the state of an object by converting it into a stream of bytes. Grid data can be serialized in one of the following three ways:

• Serialize cell content-grid cell contents can be serialized into code
  
• Serialize Range Style - Range style provides options for styling the grid cells. These cell range styles can also be serialized into code.
  
• Serialize to ResX Files-grid cell contents can be serialized to ResX files
  

Grid Grouping Control supports XML schema serialization. Grid with XML serialized schema is illustrated below:

The Grid Grouping Control's contents can be exported to an MS Excel file. The Grid Grouping Control provides options to export Style, Borders, Preview Rows and Groups. The conversion can be done in two ways: export entire control's contents or just visible contents.

The Grid Grouping Control's contents can be exported to an MS Word file. You can be able to export nested tables as well. It also supports drawing custom header and footer.

Grid Grouping Control is optimized to handle high refresh and update scenarios. Hooks were added to the Grid Grouping Control and they allow a more optimized ListChanged event logic to be plugged in. ListChanged logic is integrated into the main code base so that you can switch between old and new, more optimized code with only a few property settings. When frequent updates are being made in the grid, this has an optimal impact on the performance of the Grid Grouping Control, enabling minimal CPU usage.