Read Past End Of File

[reynolditpi]

I have a button on a form that is suppose to add a record to the child table of the set used to build the form.

The first part of the code, which i have omitted, displays a dialog box that prompts for a name. It saves the name to variable prompt_var_2

The next part of the code is listed below.

Things will work fine...and then tragedy strikes:(

For some reason, when it gets to tbl.enter_end(.t.) it gives me a "read past end of file" error.

dim tbl as p 
tbl = table.open("cyc_data")
tbl.enter_begin(.t.)
tbl.CYCLE_ID = a5_eval_expression("=Cycle_Id",local_variables())
tbl.SET_NAME = prompt_var_2
tbl.enter_end(.t.)
tbl.close()

When this error starts happening, I have tried running the code below in the interactive window with the form open, with the form closed, (when i fire the button) etc and i get the error every time.

I have another form with a button that rebuilds the indexes of the tables of this form (and other forms to boot)

If I rebuild the indexes, it will once again work...for a while.

I am not for sure why this problem occurs. Any suggestions would be useful.

I am also not for sure if i have given adequate info. Please let me know if you need more.

Thanks
Tony

Just in case, I have included the complete code from the button push below:

'Use an Xdialog box to prompt for field values.....
dim flag_ok_selected as l
flag_ok_selected = .f.
'
DIM  Prompt_var_2 as C
DIM  ui_get_parameters_result as C
Prompt_var_2 = ""
ok_button_label = "&OK"
cancel_button_label = "&Cancel"
ui_get_parameters_result = ui_dlg_box("Enter Subcycle Name",<<%dlg%
{region}
Set Name:| [.40Prompt_var_2];
{endregion};
{line=1,0};
{region}
<*15=ok_button_label!OK> <15=cancel_button_label!CANCEL>
{endregion};
%dlg%,<<%code%
if a_dlg_button = "ok" then 
	flag_ok_selected = .t. 
end if 

%code%)
if ui_get_parameters_result <> "OK" then 
	end 
end if 

	
dim tbl as p 
tbl = table.open("cyc_data")
tbl.enter_begin(.t.)
tbl.CYCLE_ID = a5_eval_expression("=Cycle_Id",local_variables())
tbl.SET_NAME = prompt_var_2
tbl.enter_end(.t.)
tbl.close()

'Refresh  'Cycle_list' in current form.
topparent:Data_list.refresh()
topparent:Data_list.fetch_last()
I have

[CODE]dim tbl as p 
tbl = table.open("cyc_data")
tbl.enter_begin(.t.)
tbl.CYCLE_ID = a5_eval_expression("=Cycle_Id",local_variables())
tbl.SET_NAME = prompt_var_2
tbl.enter_end(.t.)
ERROR: Read past end of file

tbl.close()

[/CODE]

[reynolditpi]

Re: Read Past End Of File

Ok...I was very wrong about most of what was leading up to my problem. Here is what i have tracked down.

1. form is built on a set.
2. I have a button that deletes a parent record and its children. FYI...I have set the referential integrity of the parent-child link to "cascade changes/deletes". This button uses x-basic:

tbl = table.current()
count = tbl.records_get()

if count = 0 then
    end 
    else
tbl.change_begin()
tbl.delete()
tbl.change_end(.T.)

3. I have another button that adds a parent record using similar x-basic to the script I posted early in the previous post
4. I have a 3rd button that adds child records (code shown in previous post)

Here is how I recreate the error.

I use the delete button (no. 2 from above) to delete each record until ALL records are deleted.
I then add a new parent record.
I then add a child record. No problem!!!
If i try to add a SECOND child record i get the "read past end of file" error.

However, if I close the form and pack the child table, I can then open the form back up and add child records.

Before packing the child table, I can add more parent records, but only the one child record.

very confused!!!
T

[reynolditpi]

Re: Read Past End Of File

Sorry to be a pest, but I thought I would double check and see if anybody can give me a suggestion on this issue. Unfortunately I am still having the problem.

Thanks in advance
Tony

[Stan Mathews]

Re: Read Past End Of File

Tony, since no one else has responded, I'll jump in.

The quickest was to get help is to post a sample with instructions how to replicate the problem. You've done a great job as far as explaining how to trigger your problem.

The question now is

"Do I have something similar in use where I could try this or do I want to take time to construct a set, using guesswork as to tables involved, field names, etc and hope I make something similar to what Tony is using?"

Since you see the issue when there are no records in the set, you have no worries about sensitive data. When you get to the point where the set is empty, zip up the set and attach it here for experimentation.

[MikeC]

Re: Read Past End Of File

Hi Tony--it sounds like you have a lot going on and it may be best to try and break it into parts if possible to get to the root of your problem--at least that is how I have been able to figure these things out.

I would check out you field rules too--especially since you one time chose to explicitly enforce the field rules

tbl.enter_begin(.t.)

and in another part of your script you chose not to do so (intentional maybe?).

tbl.change_begin()

EDIT: slow does not even come close to describing my condition today!!!! I started this answer a half hour or so ago and just got back to it!!!

[reynolditpi]

Re: Read Past End Of File

Thanks for the help guys.

I will be away from labtop which has alpha 5 on it until tonight. I will zip the set and post it then.

I did add some field rules...and to be honest, I cannot say if the problem occured before I added them or not. I will check into that as well.

Thanks again.
Tony

[reynolditpi]

Re: Read Past End Of File

Alright,
I have attached the set. Please let me know if I can provide anything else.

Thanks again.
Tony

[MikeC]

Re: Read Past End Of File

Tony,

In your OnPush event for creating a new subcycle record, use

tbl = table.get("cyc_data")

instead of table.open----the table is already open as the form is based on the set which has the table.

Just by changing this the error does not manifest itself and I can add subcycle records.

Hope it works for you as well.

[reynolditpi]

Re: Read Past End Of File

In the table cyc_data (child table of set) I have calculated field rules attached to the last four fields. After removing these rules the problem stopped happening.

So...I guess that is the problem. However, i really need to run these calculations during data entry. Is there another way to go about this?

T

[reynolditpi]

Re: Read Past End Of File

Great. I will try it. I hope it works to:) Maybe I can say "please disregard my last post"

[reynolditpi]

Re: Read Past End Of File

Yippie!!! Problem Fixed!
Thank you so much.
Tony

[MikeC]

Re: Read Past End Of File

Tony--Glad to hear it!! I forgot to mention that you would also eliminate the tbl.close() too as the form is still using the table. You may as well do the same for the add record button for the parent form too.

[Stan Mathews]

Re: Read Past End Of File

Yippie!!! Problem Fixed!
Thank you so much.
Tony

Tony,

Not to say "I told you so" but to point out to others who post questions on the board who might read this thread...

You tried for two days to get an answer to your original question. After posting a sample you had a solution in twenty minutes. Is there anything to be learned here?

Glad you got it fixed!