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By Yuriy, 08/04/2011 4:53 PM

I have been using WebHierarchicalDataGrid with manual load on demand bands with a pretty good success until I hit this snag.

The WHDG has correctly displayed HTML fields before, but this time a column with HTML data (an HREF link to be precise) is needed as one of the grid’s DataKeyFields to provide uniqueness of the row:

Continue reading 'WebHierarchicalDatagrid: Sys.ArgumentException: Cannot deserialize on Row Expand'»

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By Yuriy, 06/03/2011 3:35 PM

I am using FeedWordPress plugin on some of my sites to pull data from Google News RSS feeds. It was working fine, but after I moved to a new host, I started to get errors like:

Failed to connect to 2a00:1450:8006::63: Network is unreachable

Note the IPv6. Google have been supporting it for a while and news.google.com resolves to IPv6 first (similar error happens in WordPress admin dashboard in “Incoming Links” section). Unfortunately network of my new host didn’t support IPv6, so I had to find solution to force WordPress to use IPv4. Enter class-http.php. Continue reading 'Solution for WordPress CURL IPv6 error “Network is unreachable”'»

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By Yuriy, 04/25/2011 2:16 PM

UltraWebGrid had a very convenient getNextRow() client-side function which returns next row in row collection. WebDataGrid does not have an analog, but it’s pretty easy to recreate the functionality:

function getNextRow(i_oRow) {
      var iRowIndex = i_oRow.get_index();
      var aRows = i_oRow.get_grid().get_rows();

      return aRows.get_row(iRowIndex + 1)
}

This function accept grid row as a parameter, gets the row’s index and return row with incremented index from grid row’s collection.

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By Yuriy, 04/22/2011 11:38 AM

Infragistics UltraWebGrid offers standard keyboard navigation for record selection. For example you can click a row, and holding Shift key press Down Arrow to select multiple records. This works fine for a flat grid, but try this with grid in OutlookGroupBy mode and you’ll get an error ‘previousSibling’ is null or not an object:

After some digging I found the culprit. Continue reading 'Solution for ‘previousSibling’ is null or not an object error in grouped UltraWebGrid'»

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By Yuriy, 03/31/2011 9:19 AM

If you need to get/set value of a specific cell in WHDG Row (which is of GridRecord or ContainerGridRecord type) the only way to do it is by Cell index e.g.

Protected Sub xMyGrid_InitializeRow(ByVal sender As Object, ByVal e As GridControls.RowEventArgs) Handles xMyGrid.InitializeRow
   e.Row.Items(15).Value = 42
End Sub

But what if you don’t know cell/column index and only column name is known? Then the trick is to find the index first. Consider following code:

Protected Sub xMyGrid_InitializeRow(ByVal sender As Object, ByVal e As GridControls.RowEventArgs) Handles xMyGrid.InitializeRow

   Dim oParent as GridControls.ContainerGrid = e.Row.Items.Grid
   Dim iColIndex as Integer

   if oParent.Columns("MY_COLUMN_NAME") IsNot Nothing
      iColIndex = oParent.Columns("MY_COLUMN_NAME").Index
      e.Row.Items(iColIndex).Value = 42
   End If

End Sub

It’s pretty straightforward, first you locate grid to which the row belongs, then locate column in that grid by name and get index of that column and finally locate cell in the row by that index. This method will work at any depth in the WHDG hierarchy.

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By Yuriy, 03/16/2011 10:21 AM

Infragistics WebDataTree control offers extensive support of CSS for tree styling. One of the options HoverCssClass is intended to alter tree node appearance when mouse pointer hovers over it:

Unfortunately it doesn’t seem to have any effect on the tree appearance. When I set that class to simple underline node:

.fnTreeHover {text-decoration:underline}

nothing happened. I found the workaround when I noticed that the tree is rendered as an ancor tag <A> inside of <LI> tag:

The solution is to apply style to this combination:

LI A:hover {text-decoration:underline}

Bingo. Now tree nodes are underlying when mouse is over them.

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By Yuriy, 03/15/2011 2:54 PM

UNION is a very common operator used in SQL, it allows to combine result of multiple queries into one. Unfortunately if you want to sort this unified resultset sorting is applied to entire result at once. But what if you wan to sort queries-participants individually?

Let’s say you have 2 following queries from Northwind database:

SELECT TOP (5) CompanyName FROM Suppliers ORDER BY CompanyName

Aux joyeux ecclésiastiques
Bigfoot Breweries
Cooperativa de Quesos 'Las Cabras'
Escargots Nouveaux
Exotic Liquids

and

SELECT TOP (5) ProductName FROM Products ORDER BY ProductName

Alice Mutton
Aniseed Syrup
Boston Crab Meat
Camembert Pierrot
Carnarvon Tigers

And now you want to combine them into a single result, adding title lines to separate each result. The direct approach would be:

SELECT 'Suppliers' AS Name
UNION
SELECT TOP (5) CompanyName FROM Suppliers
UNION
SELECT 'Products'
UNION
SELECT TOP (5) ProductName FROM Products
ORDER BY Name

But result is far from what we wanted

Alice Mutton
Aniseed Syrup
Aux joyeux ecclésiastiques
Bigfoot Breweries
Boston Crab Meat
Camembert Pierrot
Carnarvon Tigers
Cooperativa de Quesos 'Las Cabras'
Escargots Nouveaux
Exotic Liquids
Products
Suppliers

Entire resultset is sorted uniformally and products are mixed with suppliers.
Continue reading 'Individual Sorting of SELECT queries in the UNION'»

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By Yuriy, 03/02/2011 2:39 PM

If you’re using Infragistics UltraWebGrid and manually handling grid’s RowFilterApplying event by doing your own filtering/querying and then canceling the event by setting parameter e.Cancel = True, one of the side-effects is that column filter icon never changes to “applied” image.

To work around this limitation you need to change the image yourself. This involves 2 steps:

1st step – In the server side, code in RowFilterApplying event handler loops thru filtered columns, getting column index, filtered state and calling a JavaScript function that would actually set the image:

Protected Sub xmyGrid_RowFilterApplying(ByVal sender As Object, ByVal e As UltraWebGrid.FilterEventArgs) Handles xmyGrid.RowFilterApplying

    ' ... Your own filtering/querying code

    Dim xGrid As UltraWebGrid = sender

    For Each oFilter As ColumnFilter In xGrid.Rows.ColumnFilters
         If oFilter.FilterConditions.Count = 0 OrElse oFilter.FilterConditions(0).ComparisonOperator = FilterComparisionOperator.All Then
            RunJavascript(Me, "setFilterIcon(" & oFilter.Column.Index & ", 'MyImages/ig_tblFilter.gif');")
         Else
            RunJavascript(Me, "setFilterIcon(" & oFilter.Column.Index & ", 'MyImages/ig_tblFilterApplied.gif');")
         End If
    Next

    e.Cancel = True

End Sub

During the loop code double checks if filter is applied to current column and if so passes URL of “applied” filter image to the JavaScript function – in this case “MyImages/ig_tblFilterApplied.gif”. Otherwise URL of “empty” filter is passed – in this case “MyImages/ig_tblFilter.gif”. To generate JavaScript call from ASP.NET code I am using RunJavascript function which works correctly both on normal postback and Infragistics partial postback (read WARP panel).

2nd step – And here’s JavaScript function that sets the image:

// Set's filter icon of the specifiec column
function setFilterIcon(i_iColumnIndex, i_sFilterImageURL) {
    var sThId = igtbl_getGridById('xmyGrid').Bands[0].Columns[i_iColumnIndex].Element.id;
    document.getElementById(sThId).firstChild.lastChild.src = i_sFilterImageURL
}

Using passed in column index, code locates column object and its DOM “TH” element (note: You have to get an ID of the element first, and then locate element by calling document.getElementById, using Column.Element for some reason returns an empty TH tag). Once element is located, code locates filter image inside and sets its source to passed image URL

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By Yuriy, 02/24/2011 2:01 PM

Infragistics Aikido WebDataMenu control has extensive (albeit poorly documented) client-side library of classes, method and properties. 2 methods addItem and removeItem supposedly allow you to add/remove menu items in JavaScript. These methods have been public since 9.2 release probably even earlier, but have a lot of drawbacks, one of the major ones – for every method call an AJAX call to server is made, which slows performance dramatically, breaks code flow and won’t let you set properties of newly added item.

Method described below is a bit of a hack, but it works purely client-side, no slow round trips, no waiting for AJAX call to return and you have full control of all menu items. Continue reading 'Infragistics WebDataMenu CSOM addItem/removeItem workaround'»

Comments (3)

By Yuriy, 02/22/2011 11:20 AM

Ordinary when you create a parent-child relationship between DataTables in a DataSet – there is a requirement that all values of the parent columns need to be unique. If they’re not – you will get an error: “These columns don’t currently have unique values“.

But there’re times when you need to make the relationship work even if those values are not unique. The solution is not to create constrain when creating the relationship. This can be done for example by passing FALSE as value for createConstrains parameter of Dataset.Relations.Add method:

oMyDataSet.Relations.Add("MyRel", _
oMyDataSet.Tables("TheParent").Columns("ParentColumn"), _
dtSet.Tables("TheChild").Columns("ChildColumn"), _
False)