HtmlDataGridConfig::OnBeforeRowRender

Event called just before a row is rendered in the data grid. The record to render is already loaded at this point.

This event is useful for injecting content before a row is rendered such as group headers.

This handler is useful for:

  • Formatting the entire row with custom styles or CSS classes
  • Injecting header rows into the grid
  • Formatting HtmlDataGridConfig Columns based on certain conditions

Important

The expression that runs must return a string! Return empty to do nothing, or return a string that returns HTML - typically a <tr></tr> block that renders for things like headers, that render before the row.

Examples

To set up a function handler use OnBeforeRowRender like this:

select * from albums into cursor TQuery


loConfig = CREATEOBJECT("HtmlDataGridConfig")

*... other configuration settings

*** Note you can pass loConfig (always!!!) to your function
loConfig.OnBeforeRowRender = "Process.HighlightAlbumRowByYear(loConfig)"

HtmlDataGrid("TQuery",loConfig)

You then implement a method the method you referenced - typically on the Process class, but it can be any FoxPro function or class method as long as it's in scope.

Modify Row Styling

This method creates custom styling on the row using the RowAttributeString property:

FUNCTION HighlightAlbumRowByYear(loConfig)

lnYear = TQuery.Year  && you can access the iterating cursor

*** figure out some condition
if (lnYear > YEAR(Date()) - 10)
    loConfig.RowAttributeString = [ class="highlight" ]
ELSE
    loConfig.RowAttributeString = ""
ENDIF

*** optionally return a string to inject HTML before the row
RETURN ""

Note that the full expression is provided in quotes and that any objects accessed or passed must be in scope. To get a reference to the HtmlDataGridConfig object in the handler method pass in loConfig as a parameter (regardless of the name you use!). Note that the active cursor/alias will be active when the row is rendered so you can access the cursor as needed in the handler code.

Inject another row - like a group header

*** pcLastCompany - PRIVATE string expected to exist
PROTECTED FUNCTION ShowHoursBeforeRowRender(loConfig)
LOCAL lcHtml 

lcHtml = ""  && Return empty if not matched

*** Check if the company in the data row has changed - if it has write out a header row
IF pcLastCompany # Client
   lcHtml = [<tr class="groupheader"><td colspan="6"><a href="showclient.wwd?id=] + custno + [">Client + [</a></td></tr>] + CRLF
   pcLastCompany = Client
ENDIF

RETURN lcHtml   
ENDFUNC
o.OnBeforeRowRender()

Return Value

Return a string with the HTML to render before the row is rendered or "" to render nothing


Remarks

The expression can pass the loConfig object as a parameter to get the wwDataGridConfiguration instance and all of its support properties.

See also:

Class HtmlDataGridConfig

© West Wind Technologies, 1996-2019 • Updated: 06/29/16
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