String Conconcatenation - Hitting Character Limit Issue

richardc

Hi,

I am using the BIRT CONCATENATE function for an aggregation element which is inside a group footer in my report layout.
I would like to concatenate several large pieces of text (over 1000 characters each) but there seems to be a limit on the number of characters that can be concatenated.
The total number of characters in the concatenated string seems to be limited to just over 1000 chars - anything over is ignored and no error messages are displayed.
I am using an XML dataset to read an XML datasource file.

Results from my tests (Birt version 2.3.2.2):

Test 1 - concatenate two strings - String 1 with 490 chars and String 2 with 495 chars.
Result: correctly concatenates - (concatenated string has total of 985 chars)


Test 2 - concatenate two strings - String 1 with 615 chars and String 2 with 605 chars.
Result: only shows String 1 as the concatenated result (totally ignores String 2 and no error message is displayed. - (resulting string has total of only 615 chars)


Test 3 - concatenate ten strings - each with less than 120 chars
Result: only concatenates the first 8 Strings (totally ignores the last two Strings) - (resulting string has total of only 947 chars)


Some questions:

1) Is there a StringBuffer being used in the concatenation - if yes, why is there a limitation on the concatenated result?

2) Is there a way that I can code my own concatenation without using the BIRT CONCATENATE function? I would need a way to determine when to start and stop the concatenation whilst inside a group - can you please advise on how to do this? i.e. if I use script in the onFetch method for the XML dataset, is there a way that I can determine when I'm in the first row of the group and when I'm in the last row of the group?

mwilliams

Hi richardc,

If you've got the dataSet bound to a table, you can probably create a variable in your report's initialize script method and add each row to the variable in the onCreate method of the detail row in your table. Then display the variable in a dynamic text box in your group footer. You can reset the variable to an empty string in the onCreate of the group header of the table so it starts fresh as a new group starts.