Saving Variables

[Dan ONeill]

In Alpha Four I could easily save all my Variables to a text text file by using {VSAVE}. How can I do this in A5?

Thanks

[Stan Mathews]

RE: Saving Variables

Not so easily but you can write them, via xbasic, to a .dbf created for the purpose, and read them back by the same method attached to the onnit event for your startup form.

[whanigsberg]

RE: Saving Variables

Dan,

As you know, vsave writes the values of variables to a text file. You get them back by using vrestore which reads the values in the text file back into variables. That way the values persist from one session to the next.

When I first made the transition to A5 I wrote my own versions of vsave and vrestore. This was not so difficult and it had the benefit of familiarity.

After that first application I went to the method Stan describes which I found to be somewhat more convenient. After all, if you have tables available why would you want to store data in a text file?

I just thought you might like to know that you can do it Alpha4 way if you want. Further details upon request.

Bill

[Dan ONeill]

RE: Saving Variables

Thanks for your reply. We've got 36 users on a Novell network and it's been very useful to be able to save an individuals variables when they exit the program. I read them back in when the program is started, just as you described Bill and the user can pick up where they left off. There is always a tendency to want to fall back on familiar methods and I would like to know how I can continue to use a text file but I need to learn the Table method also. If you can provide a couple of samples of code I sure would appreciate it. I shouldn't need much, just something to get me started.

Thanks

[Stan Mathews]

RE: Saving Variables

Nice article at learn alpha.com, click here

[whanigsberg]

RE: Saving Variables

Dan,

Here is a fragment of a script which initializes variables from a defaults table. The table contains a record for each user so the defaults are user-specific even though they are stored centrally.

I can add that I do store a single value in a local text file. The file contains a single line with the name of the department logged on to the last time that particular machine ran the application. It saves the user the trouble of scrolling down a list to find it and is almost always correct as the machine is on a user's desk. The reason it must be in a local text file is that is is used *prior* to logon so I don't yet know the user name to do the lookup.

I'd be happy to send you more if you want but this shows the technique and the article Stan flagged does the same.

Bill


''XBasic
'CPL_Ini_9
'This script is called by Autoexec (Logon) script
'It has other aspects which I have removed for simplicity
'
'Explicitly Declare Variables

dim tbl as p 'defaults table
dim ndx as p
dim global user_key as c 'initialized in logon
'this means that I can identify the user's defaults record
dim global term_S as c 'Start term
dim global term_E as c 'End term
dim global term_D as c 'Default term
'---------------------------------------------------------
'Initialize global variables from saved defaults to use in filtering data forms
'Defaults are user specific
tbl=table.open("defaults.dbf")
ndx=tbl.index_primary_put("User")
tbl.fetch_find(user_key) 'fetch record holding current user's defaults
term_S=tbl.Term_start
term_E=tbl.Term_end
term_D=tbl.Term_default
tbl.close() 'close defaults table
'-----------------------------------------------------------

[Dan ONeill]

RE: Saving Variables

Bill,

Thank you very much. I got a little sidetracked this week and I'm just now getting back to this. Your snippet of code is very helpful. That looks like the way to go. I would like to see how you did the text file thing though.

Thanks again,

Dan

[whanigsberg]

RE: Saving Variables

Dan:

Here is a pair of scripts that do it the A4 way. Guess what they are called (vsave, vrestore). There is a lot of specific junk in these scripts which you can ignore but they show the way it works.

The application is meant to work with a large or small monitor. There are two application main forms. By default it loads the small forms. The idea is to remember the forms which were active when the application closed so it restores the same the next time it is opened.

The annotations also call attention to getting form names into pointers which is worth knowing.

Feel free to query me on the many obscurities which must be there to confuse you (and me as I no longer remember the code very well).

Bill

''XBasic VSAVE (from CPLFile_Exists3)
'Thread and Topic forms must both be loaded for this to work
'===============================================================
'Test threads and topics are loaded
'Get the names of the current forms
'Test for existence of a text file.
'If it does not exist prompt user to decide whether to create it.
'If the file exists or is created, write variables to it.

On Error goto ERROR_HANDLER
Option Strict


dim threadform as c
dim topicform as c
dim global thr as p
dim global top as p
dim message as c
dim file_pointer as p
dim filename as c
dim result as L
dim err as c
dim msg as c

dim crlf as constant
crlf=chr(13)+chr(10)

'Test forms are loaded. If not don't try to save.
If .not. is_object(thr) THEN
message="One or more application forms is not currently loaded"+crlf+
"Not worth saving current forms."
ui_msg_box("Missing information",message,UI_INFORMATION_SYMBOL)
END
End If

If .not. is_object(top) THEN
message="One or more application forms is not currently loaded"+crlf+
"Not worth saving current forms."
ui_msg_box("Missing information",message,UI_INFORMATION_SYMBOL)
END
End If

'Forms are loaded so get their names from pointers

'here's how
'thr=form.view("thread new3")
'threadform=thr.name()
'?threadform
'= "thread_new3"

threadform=thr.name()
topicform=top.name()



dim path as c
path=:A5.Get_Private_Path()
filename=path+"TECHBOARD.txt"
result = File.Exists(filename)

IF result = .F. THEN
message="Creating text file to remember current forms for next time."
ui_msg_box(filename+" not found",message,UI_INFORMATION_SYMBOL)
file_pointer=File.create(filename,file_rw_exclusive)
goto WRITE

ELSE
'since file already exists there is no need to create it
file_pointer=File.open(filename,file_rw_exclusive)
END IF

WRITE:
'1;File_pointer.Write_line(threadform)
'2;File_pointer.Write_line(topicform)


file_pointer.flush()
file_pointer.close()
END

ERROR_HANDLER:
On Error goto 0
err=error_code_get()
msg=error_text_get(err)
ui_msg_box("Error",msg)
END


''XBasic VRESTORE
'This is the only script which stores literal names of all forms
'Test for existence of a text file containing names of last-used forms
'If file does not exist inform the user and initialize small forms
'If the file exists read the names last-used forms from it and open them
'=======================================================================
On Error goto ERROR_HANDLER

dim global vThreadform_s as c 'these variables hold literal form names
dim global vThreadform_l as c 'to use in setup_large.scp
dim global vTopicform_s as c 'and setup_small.scp
dim global vTopicform_l as c

dim path as c
dim global threads as c 'global for switch_forms.scp
dim global topics as c
dim global thr as p
dim global top as p
dim message as c
dim file_pointer as p
dim filename as c
dim result as L
dim err as n
dim msg as c

dim crlf as constant
crlf=chr(13)+chr(10)

vThreadform_s = "thread_s" 'Literal names of forms into variables
vThreadform_l = "thread_l"
vTopicform_s = "topic_s"
vTopicform_l = "topic_l"

'DEBUG(1)

'Look for text file holding saved setup

path=:A5.Get_Private_Path() 'private path is available during an autoexec script
filename=path+"TECHBOARD.txt" 'whereas a_db_current_path is not
result = File.Exists(filename)

IF Result = .T. THEN 'Application saved last-used forms retrieve their names
'nb these are literal names and not pointers

file_pointer=File.open(filename,file_ro_exclusive)
threads=File_pointer.Read_line()
topics=File_pointer.Read_line()
file_pointer.close()

ELSE 'Inform the user and use small forms as a default
message="TECHBOARD.txt doesn't exist. When you close the application"+crlf+
"the forms you use will be remembered for next time."+crlf+crlf+
"Using small forms as a default."+crlf+crlf+
"Choose 'Switch_Forms' on the menu to change to large forms."
ui_msg_box("No saved forms found",message,UI_INFORMATION_SYMBOL)

threads = vThreadform_s
topics = vTopicform_s

END IF

'Now load the actual forms
:Statusbar.Set_Text("Loading application forms")
:Statusbar.Disable()
thr=form.load(threads)'Get the character variables into pointer variables
thr.Index_Set("Headline")
thr.show()
thr.activate()

top=form.load(topics)
top.Index_Set("Title")
:Statusbar.Enable()
:Statusbar.Clear()

END

ERROR_HANDLER:
On Error goto 0
err=error_code_get()
msg=error_text_get(err)
ui_msg_box("Error",msg)
:Statusbar.Enable()
:Statusbar.Clear()
END

[Dan ONeill]

RE: Saving Variables

Holy Smokes! Thank you Bill!