Error Auto Writing to Memo Field

[Dale Bradt]

I have an application that contains a Form with a Memo Field. This Memo Field is used as a log for changes to the record. When entering the Change mode of a record, I capture the values of various fields. Then when the record is saved a comparison is done for each field. If the field has been modified I add a line of text to the Memo Field used as a log. While testing this function out I found that it works quite well. However there seems to be a problem when the Memo Field reaches a certain size. Actually it�s when the variable that is trying to hold the contents of the Memo Field in the script that I�m using that has the problem. I used the action script builder to build my script then I converted it to xbasic. It looks like it reads the Memo Field into a variable and then adds the text that I want to add, then rewrites the field. I�m thinking a character buffer is getting overloaded or something along those lines. If you have written code using the action builder you will recognize the variables. The Error Dialog Box says:

Script:auto-update-stat line:255
TempObj:Text=MemoText
TempObj:text subproperty cannot be assigned to

Anyone have any ideas on how to correct this problem?

Thanks in advance.

Dale

[Stan Mathews]

RE: Error Auto Writing to Memo Field

I can't tell from the syntax whether

TempObj:Text is an object or a property.

Seems it should be

TempObj.Text=MemoText
(if tempobj is a field on a form)

or

TempObj:Text.text=MemoText
(if tempobj:text is field on a form "tempobj")

Depends on the context.

[Dale Bradt]

RE: Error Auto Writing to Memo Field

Stan,

TempObj is a pointer. The following dim statement is before the use of TempObj

'Dim TempObj as p'

TempObj is loaded by this line of code.
'TempObj = obj(topparent.name(16)+":"+"Status_note")'

Status note is the name of the Memo Field and MemoText is a character variable that is a combination of what is already in the field + A new line of text to be added.

Dale

[Stan Mathews]

RE: Error Auto Writing to Memo Field

So I think the first case applies. Alpha uses colons to separate parts of an object address. The period is used to "apply" methods and "refer" to properties.

The text of the object "TempObj" is denoted by

TempObj.text

[Dale Bradt]

RE: Error Auto Writing to Memo Field

Yes,

Your correct! I'm sorry, I didn't look close enough, the error dialog is:

Script:auto-update-stat line:255
TempObj.Text=MemoText
TempObj.text subproperty cannot be assigned to

Like I said, the script runs fine until the amount of characters being held in the variable gets too large.

Dale

[Stan Mathews]

RE: Error Auto Writing to Memo Field

Makes more sense now, at least to me. Doesn't get us any closer to a solution, though. Sorry.

[Tom Cone Jr]

RE: Error Auto Writing to Memo Field

Dale,

I have little experience with memo fields. However, two ideas occur:

1) you could write the existing memo field text to a temp disk file, append the new text there, then import it back to the memo field. (while theoretically possible, this sounds very slow to me)

2) you could rework the design of the application. Instead of using a single memo field to track all changes that might ever occur to the one record, use a simple table to track changes to the primary table, and write to it each time a change occurs. Each record in the 'change_log' table would contain the particulars on the change including: identifier for the record being changed, date changed, time changed, field name changed, identity of user, old field value, new field value.

-- tom

[Dale Bradt]

RE: Error Auto Writing to Memo Field

Tom,

Your second option may work. But it does not explain why my script of adding text to a memo field works until it becomes a certain size, and then errors.

Is the character buffer for a variable of a specific size?

Dale

[Tom Cone Jr]

RE: Error Auto Writing to Memo Field

Dale, I don't know.

Since char type fields in tables are limited to 255 characters, and expressions are limited to 1024 characters, it would not surprise me to learn that char type variables are also limited to something less than available memory.

Have you tried counting characters to see where the problem crops up?

-- tom

[Dale Bradt]

RE: Error Auto Writing to Memo Field

Tom,

It errors after 956, so I think you hit it with 1024 being the magic number. I wonder if this can be increased?

Until I get an answer I'll explore your other 2 ways of creating a change log.

Thanks,

Dale

[Elke]

RE: Error Auto Writing to Memo Field

Does anyone know if this issue has been addressed?

I have a memo field that I would like to be able to add text to but not change or delete previous text. I created a button using an XDialog Box to enter the notes and then adding the variable along with date and user initials to the memo field. Works fine unless there are already alot of notes entered.

[Tom Cone Jr]

RE: Error Auto Writing to Memo Field

Elke,

In reviewing the thread it seems the problem occurs when the memo field text is stored in a variable.

Is this necessary to do in the first place?

Have you tried working with a pointer to the memo field directly? Something like this:

tbl = table.current()
tbl.change_begin()
tbl.memo_field_name = tbl.memo_field_name + "Your new text"
tbl.change_end(.t.)

???

-- tom

[martinwcole]

RE: Error Auto Writing to Memo Field

I ran into this recently, and I was having the same problem.

a field on my form, say, is "LogNotes"
"LogNotes" is a memo field.

in a script, I say

lognotes.value="" 'recalculate from scratch - blank it
temp="" 'my character variable for storing the string in

temp="Changes Made to Parent:" + crlf()
temp=temp + changes1 + crlf()
temp=temp + changes2 + crlf()
lognotes.text=lognotes.text + (temp)
temp=""

temp=crlf() + "Changes Made to Child:" + crlf()
temp=temp + changes1 + crlf()
temp=temp + changes2 + crlf()
lognotes.text=lognotes.text + (temp)


I originally was saying lognotes.value + temp, but after about 25 lines, it bombed, but changing it to lognotes.text + temp fixed it

[Elke]

RE: Error Auto Writing to Memo Field

Only works until the notes field has less than 1024 characters.

[Tom Cone Jr]

RE: Error Auto Writing to Memo Field

Elke,

the example I gave, using a pointer to the currenty lengthy note field, works fine. It's not necessary to store the text of the current note field in a variable in order to extend it through concatenatioin with other text.

If you need an example of this let me know. I just built one that adds the same 65 character string to a memo field 50 times in a row.

-- tom