{"id":103,"date":"2009-07-26T18:12:00","date_gmt":"2009-07-26T18:12:00","guid":{"rendered":"\/lisa\/post\/2009\/07\/26\/YAPS-about-Dynamic-Layouts.aspx"},"modified":"2021-10-12T08:50:04","modified_gmt":"2021-10-12T15:50:04","slug":"yaps-about-dynamic-layouts","status":"publish","type":"post","link":"https:\/\/spacefold.com\/lisa\/2009\/07\/26\/yaps-about-dynamic-layouts\/","title":{"rendered":"YAPS about Dynamic Layouts"},"content":{"rendered":"

Ehud Kafri wrote on a\u00a0moribund thread in the SQL Server RS \u00a0forum<\/a>\u00a0to ask:<\/p>\n

Hi Lisa,
\nI have a simelar problem, I have a list item that recive a collection of objects that were made specificly for this report.
\nthe problem is i need the size and location of the textboxs to be decided according to the parameters defind on each object in the collection.
\nex’ : i have: \u00a0 \u00a0 String ValueForDisplay
\nint Position \u00a0 \/\/ enum value like : Top; NewRow; SameRow and so on
\nDouble Width
\nDouble Hieght
\nnow what I could not figure out is how to, in run time, set these values.
\nI prefer not to dynamicly create a new rdlc file on each run but so far that is the only way I have found to do this.
\nI’m using VS 2005, C#, .Net 2.0
\nThanks<\/p><\/blockquote>\n

After some back-and-forth, some things became clear.<\/p>\n

The problem Ehud is facing is this: some things can be dynamically set on a report object, such as font and color, and some cannot.\u00a0 Top and Left, Width and Height,\u00a0are among the things that cannot be set dynamically for each instance of each object during a report run.<\/p>\n

Why not, and what can we do about it?<\/p>\n

First, understand why not<\/h3>\n

Think about the ramifications of setting these particular attributes on the fly, on the report layout as a whole.\u00a0 When a textbox moves to a new position, for example lower on the page,\u00a0what should happen to the other elements “below” it?<\/p>\n

You could answer “I’m going to set the top and left for all of them, too, so what’s the problem?” Maybe you are, and maybe you aren’t, I think Ehud is not doing that, but if you are, I don’t really see the point of using the RDL to render your report any more.\u00a0 You might as well call the rendering engine of your choice (be it PDF or whatever) directly, or just write your own, rendering items within a canvas of the appropriate page layout size however you want to.<\/p>\n

Part of the point of the RDL data regions (whether we’re talking table, matrix, tablix, or list) is to allow the report engine to iterate through repeating items and figure out the positioning and the pagination itself.\u00a0 To a certain degree, you can issue runtime instructions to it that will force dynamic behavior, for example, you can use “Can shrink” and “Can grow” so that, should the content item have different content on each row.\u00a0 When you do this, if there is also content below<\/strong> the item that’s shrinking and growing, this other content will move appropriately too.<\/p>\n

I’ll have more to say on how you can use those properties to your advantage at some other point, because I can already tell I’m not going to get to the end of this topic in one “go”. I have mentioned it in other contexts, such as building a strange report to support RDLDocumenter<\/a>, in the past.<\/p>\n

This is the magic of any data-handling rendering construct, whether it’s a repeater in ASP.NET, an HTML table, or a data-region in an RDL.\u00a0 When you seek to interfere with this behavior — by setting the top, left, height, and width values yourself — you’re really asking for trouble.\u00a0\u00a0 You’re not giving the RDL a chance to do what it was designed to do.<\/p>\n

Or, we could talk some more<\/h3>\n

That being said…\u00a0 Ehud’s situation is a little different.\u00a0 He’s not trying to re-do the dimensions and positions of every textbox in his form.\u00a0 He’s trying to make one report serve for many different customers with some variation — a classic “corporate stationery” problem.\u00a0 Some people like their header to the left of their corporate logo, some people want it to the right.\u00a0 Some people want the address of the recipient in a different place than others, because they have different window envelopes.<\/p>\n

Ehud’s case is a little more business-domain specific than that, but, when you put it in the proverbial nutshell, it’s a situation we have all experienced.\u00a0 So, how do we crack this proverbial nut?<\/p>\n

Ehud uses an object data source, which I won’t attempt to reproduce here. I don’t have a lot of experience with that type of thing,\u00a0but I imagine that each row of his object dataset represents one instance of an object, with various attributes of various items to be displayed — such as font and position information — available for that row.<\/p>\n

For my attempt to reproduce his situation, I’m going to torture some sales data to give me some random results that represent instructions for one textbox and one image, such as you might have in “corporate stationery”.<\/p>\n

 <\/p>\n

SELECT
\n<\/span>\u00a0\u00a0 DAY<\/span><\/span> (<\/span><\/span>Requested_Ship <\/span>)<\/span><\/span> *<\/span><\/span> 6 <\/span>As<\/span><\/span> [Text1Left]<\/span>,
\n(<\/span><\/span>Month<\/span><\/span>(<\/span><\/span>Requested_Ship<\/span>)<\/span><\/span> %<\/span><\/span>6 <\/span>)<\/span><\/span> *<\/span><\/span> 10 <\/span>AS<\/span><\/span> [Text1Top] <\/span>,
\n<\/span><\/span>\u00a0\u00a0\u00a0ID <\/span>+<\/span><\/span> CHAR<\/span><\/span>(<\/span><\/span>13<\/span>)+<\/span><\/span>CHAR<\/span><\/span>(<\/span><\/span>10<\/span>)<\/span><\/span> +<\/span><\/span> Revenue_Type <\/span>+<\/span><\/span> CHAR<\/span><\/span>(<\/span><\/span>13<\/span>)+<\/span><\/span>CHAR<\/span><\/span>(<\/span><\/span>10<\/span>)<\/span><\/span> +<\/span><\/span> Juris <\/span>AS<\/span><\/span> [Text1Content]<\/span>,<\/span><\/span>
\n<\/span>\u00a0\u00a0 CASE<\/span><\/span>
\n<\/span>WHEN<\/span><\/span>\u00a0ID <\/span>LIKE<\/span><\/span> ‘%w%’<\/span><\/span> THEN<\/span><\/span> ‘Red’<\/span><\/span>
\n<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0 WHEN<\/span><\/span>\u00a0ID <\/span>LIKE<\/span><\/span> ‘%5%’<\/span><\/span> THEN<\/span><\/span> ‘Green’<\/span><\/span>
\n<\/span>ELSE<\/span><\/span> ‘Blue’<\/span><\/span> END<\/span><\/span> AS<\/span><\/span> [Text1FontColor]<\/span>,
\n<\/span><\/span>\u00a0\u00a0 CASE<\/span><\/span>
\n<\/span>WHEN<\/span><\/span> Sales_No <\/span>LIKE<\/span><\/span> ‘%3%’<\/span><\/span> THEN<\/span><\/span> ’10’<\/span><\/span>
\n<\/span>ELSE<\/span><\/span> ’16’<\/span><\/span> END<\/span><\/span> AS<\/span><\/span> [Text1FontSize]<\/span>,
\n<\/span><\/span>\u00a0\u00a0 CAST<\/span><\/span>(<\/span><\/span> RIGHT(<\/span><\/span>Sales_No<\/span>,<\/span><\/span>2<\/span>)<\/span><\/span> AS<\/span><\/span> INTEGER<\/span><\/span>)<\/span><\/span> *<\/span><\/span> 3 <\/span>AS<\/span><\/span> [Image1Left] <\/span>,
\n(<\/span><\/span>DAY<\/span><\/span>(<\/span><\/span>Released_To_Mfg<\/span>)<\/span><\/span> %<\/span><\/span> 20<\/span>)<\/span><\/span> *<\/span><\/span> 10 <\/span>AS<\/span><\/span> [Image1Top]<\/span>,
\n<\/span><\/span>\u00a0\u00a0 CASE<\/span><\/span>
\n<\/span>WHEN<\/span><\/span> DAY<\/span><\/span>(<\/span><\/span>Requested_Ship<\/span>)<\/span><\/span> %<\/span><\/span> 2 <\/span>=<\/span><\/span> 0 <\/span>THEN<\/span><\/span> ‘gear’<\/span><\/span>
\n<\/span>ELSE<\/span><\/span> ‘leaf’<\/span><\/span> END<\/span><\/span> AS<\/span><\/span> [Image1Content]<\/span>,<\/span><\/span>
\n25 <\/span>AS<\/span><\/span> [Image1Width]
\n<\/span>FROM<\/span><\/span> OrderHeader\u00a0<\/span><\/p>\n

 <\/p>\n

The resulting (silly) data looks like this:<\/p>\n\n\n\n\n\n\n\n\n\n\n
\n

Text1 Left<\/p>\n<\/td>\n

\n

Text1 Top<\/p>\n<\/td>\n

\n

Text1 Content<\/p>\n<\/td>\n

\n

Text1 Font Color<\/p>\n<\/td>\n

\n

Text1 Font Size<\/p>\n<\/td>\n

\n

Image1 Left<\/p>\n<\/td>\n

\n

Image1 Top<\/p>\n<\/td>\n

\n

Image1 Content<\/p>\n<\/td>\n

\n

Image1 Width<\/p>\n<\/td>\n<\/tr>\n

\n

120<\/p>\n<\/td>\n

\n

0<\/p>\n<\/td>\n

\n

1-63ABO\u00a0 Sales\u00a0 ARGE<\/p>\n<\/td>\n

\n

Blue<\/p>\n<\/td>\n

\n

10<\/p>\n<\/td>\n

\n

132<\/p>\n<\/td>\n

\n

30<\/p>\n<\/td>\n

\n

gear<\/p>\n<\/td>\n

\n

25<\/p>\n<\/td>\n<\/tr>\n

\n

126<\/p>\n<\/td>\n

\n

10<\/p>\n<\/td>\n

\n

1-714CI\u00a0 Loan\u00a0 NVDA<\/p>\n<\/td>\n

\n

Blue<\/p>\n<\/td>\n

\n

10<\/p>\n<\/td>\n

\n

183<\/p>\n<\/td>\n

\n

30<\/p>\n<\/td>\n

\n

leaf<\/p>\n<\/td>\n

\n

25<\/p>\n<\/td>\n<\/tr>\n

\n

60<\/p>\n<\/td>\n

\n

0<\/p>\n<\/td>\n

\n

1-63D3L\u00a0 Conversion<\/p>\n<\/td>\n

\n

Blue<\/p>\n<\/td>\n

\n

10<\/p>\n<\/td>\n

\n

123<\/p>\n<\/td>\n

\n

30<\/p>\n<\/td>\n

\n

gear<\/p>\n<\/td>\n

\n

25<\/p>\n<\/td>\n<\/tr>\n

\n

36<\/p>\n<\/td>\n

\n

0<\/p>\n<\/td>\n

\n

1-63D59\u00a0 Conversion<\/p>\n<\/td>\n

\n

Green<\/p>\n<\/td>\n

\n

10<\/p>\n<\/td>\n

\n

3<\/p>\n<\/td>\n

\n

90<\/p>\n<\/td>\n

\n

gear<\/p>\n<\/td>\n

\n

25<\/p>\n<\/td>\n<\/tr>\n

\n

42<\/p>\n<\/td>\n

\n

0<\/p>\n<\/td>\n

\n

1-63D6X\u00a0 Participation<\/p>\n<\/td>\n

\n

Blue<\/p>\n<\/td>\n

\n

10<\/p>\n<\/td>\n

\n

183<\/p>\n<\/td>\n

\n

140<\/p>\n<\/td>\n

\n

leaf<\/p>\n<\/td>\n

\n

25<\/p>\n<\/td>\n<\/tr>\n

\n

168<\/p>\n<\/td>\n

\n

30<\/p>\n<\/td>\n

\n

1-KMHWI\u00a0 Sales\u00a0 MSST<\/p>\n<\/td>\n

\n

Red<\/p>\n<\/td>\n

\n

10<\/p>\n<\/td>\n

\n

213<\/p>\n<\/td>\n

\n

20<\/p>\n<\/td>\n

\n

gear<\/p>\n<\/td>\n

\n

25<\/p>\n<\/td>\n<\/tr>\n

\n

120<\/p>\n<\/td>\n

\n

0<\/p>\n<\/td>\n

\n

1-644TS\u00a0 Loan\u00a0 NVDA<\/p>\n<\/td>\n

\n

Blue<\/p>\n<\/td>\n

\n

16<\/p>\n<\/td>\n

\n

228<\/p>\n<\/td>\n

\n

90<\/p>\n<\/td>\n

\n

gear<\/p>\n<\/td>\n

\n

25<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

To create the right conditions for applying the above values, we’ll follow these principles:<\/p>\n

    \n
  1. Determine the lowest values that top and left are allowed to have for each movable report item.<\/li>\n
  2. Create a suitable layout control (in this case, one image and one textbox) for each item at that position.<\/li>\n
  3. Consider that top\/left as 0,0, and the “real” top left as a pair of offsets for that item.<\/li>\n
  4. Similarly, determine the highest values that width and height are allowed to have for each item.\u00a0 Make those values the actual width and height for the item.<\/li>\n<\/ol>\n

    Don’t worry that this strategy may overlay various layout controls on top of each other.\u00a0<\/em><\/p>\n

    In my example, I’ve created a list in the layout (because that’s what Ehud is using).\u00a0 You can see it as a red border in the screenshot of the Report Designer below.\u00a0 I’ve created an image control and a text box that each uses almost the entire space of the list; that is, each item is allowed to be anywhere in the list.<\/p>\n

    I’ve staggered their positions slightly, and added a black rectangle inside the list that contains both the image and the text box, for the screenshots; otherwise you would not be able to see both controls at all; they could occupy exactly the same space in the layout if you want. Add any other, non-movable, controls wherever they are supposed to be, overlaying them on these “max sized” items as needed.<\/p>\n

    \"\"<\/p>\n

    If Ehud wanted to use the RS Excel output, we couldn’t pull this trick; overlaid objects are murder in the standard RS Excel. Of course you can use XSLT to fix that, as we have done in the past<\/a>. For PDF and HTML output, as well as image file exports, this will work fine.<\/p>\n

    Now comes the cute trick<\/h3>\n

    My painting teacher used to say “draw the negative space”.\u00a0 And that’s what we have to do here.<\/p>\n

    We can’t adjust the positional and size attributes using expressions, but we can tell the RDL to reserve space in the layout, where the layout controls may<\/em> be rendered.\u00a0 That’s what we’ve done so far.<\/p>\n

    Now all we have to do is subtract the part of this reserved space in which we don’t want to render our content, using Padding properties, which we can, indeed, supply as expressions.<\/p>\n