> From: Doug Hall <[email protected]>
> To: 4D iNug Technical <[email protected]>
> Subject: Upgrading 2004 to v15
RE: Should I shoot for an interim version, say v13, or is
it possible (practical) to go all the way from 2004 to v15?
Doug;
Definitely do not bother with incremental version upgrading unless you are in
version 2003 or before and then all you need do is convert to 2004 and then
straight to v15. v15 is much better at the conversion and properly auto
populates the new primary keys. While I don’t recall which versions, some
earlier versions (v13 - v14?) had an issue where updating the final datafile
did not populate and save the new keys so you had to write code to fill them
in. v15 handles this very fast.
v2004 has a unique checkbox when running 4D Tools Repair Structure “Rebuild all
forms”. You must do this with 2004 Tools or many of your forms will function
like static pictures of what once were tab-able objects. I’m not going to get
into why other than make sure you do this or you will be starting over in 2004
or rewriting lots of forms later.
I have done quite a few from 2004 to v15 and the process can be fairly simple
to complex depending on:
- plugins used
- web application situation (some such as contextual have to be completely
re-written)
- how many deprecated commands you have used
- how many deprecated objects such as “linked arrays” you have on forms
- how far back in the 4D family your application originated (just more issues)
apps written in 2004 and later will convert quicker and easier than
apps that originated in v1.04
Consider this before you get in too deep:
- Read the all 4D upgrade documents carefully as much is covered there
- Reach out to Bob Miller with Parker Hannifin as he did a session at the 4D
2016 Summit that went into great detail on "Upgrade Phobia". No sense in
covering what has all been so adequately done. Most applications will be
affected by a small fraction of all the upgrading issues so do not be
discouraged by all the possibilities. Its not that difficult unless you start
converting before you digest the relevant material and have to re-do your work
(which I did several times by the way)
- Try to Locate Thomas Maul’s summit session documents on conversions (2014 ?
2015? I don’t recall) . He too had some helpful material.
Maybe your 4D sales rep will help you obtain these docs as I’m sure
they would be happy if you upgraded. I’m not sure how publicly available they
are. They cover the nuances and hindsight that the 4D docs don’t have.
Some hindsight information I picked up:
The consensus of deprecated commands that are replaced with __o__ seems to be
leave them alone for now rather than globally replacing them (unless you have
lots of extra time for the conversion). There is code out there that will go
through your methods and update them all but the thought was you will lose
track of where all these instances were. The application will run as is
because the commands still function. This allows you to later go through the
code and replace them making sure there are no unintended consequences. An
example of that would be if you relied on set string lengths of variables to
control input. C_string(12;…) will now function as C_TEXT(), so your converted
app may have some string bugs but it will run.
Note that much has already been said about Primary Keys so I’m only going to
touch on summary of what I took away.
- UUID or LI is a personal preference - both work fine
- UUID would be better for syncing with outside data sources
- LI is a bit faster/smaller and more “human readable” if you have to pick
through any data some day
- Its always safe to simply let 4D create a new ID field (your preference UUID
or LI)
- Some developers with legacy applications decided to use these primary keys
only for 4Ds journaling and leave their legacy key systems in place. Let 4D
create keys for all tables just to allow the new 4D journaling. Its fast and
datafile space is cheap these days.
- If you have an obvious field that is unique and can function as a LI key it
is certainly safe to use it.
John Bernhoft
Myriad Systems LLC
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