Fix existing or rebuild?

[Fehfeh]

I'm working as a webdeveloper in a firm that has an existing zen-cart store which I have no idea how old is. The first thing i did was to redesign their store and upgrade it to the latest zen-car (at that time 1.3.9h) but after a while I found that the override system is completely f* and the template they use is very difficult to alter the way I want it.

Now I am at a point where i'm torn between whether to do a clean install and start from scratch (using the existing DB), or to just install a new template and customize, or build one myself. The problem however is that the people that have been working on this shop from the beginning are not developers and they have not documented a single step of previous customization, overrides, mod installs etc. so I have really no clue to what they've done in the past.

Anyone been in this situation before? What did you do, or what do you recommend?

[stevesh]

It depends to some degree on how many mods they/you have installed. Many mods haven't been updated to work with version 1.5 yet (if they ever will be), so you'll need to see what mods you can't live without and make your decision accordingly.

In your position, I'm inclined to start over. Most Zenners, IMO, install too many mods, so this would be a good opportunity to clean up that part of the installation. Also, any site which has used the same template for a long time is probably dated and in need of a face-lift anyway.

[kuroi]

We treat every new client as though this were the situation, even when they're able to provide a list of what they've done, as we've yet to see a list that was complete.

We go back to basics and do a complete file comparison (we're huge fans of "Beyond Compare") between the site and the version that it purports to be to identify all changes. Then we look for clues as to whether they're part of an add-on mod to separate those from custom changes.

We reverse engineer custom changes to work out what they were trying to do, and whether they are actually doing that. When a site's been tweaked by non-professionals or their SEO experts, it's quite normal to discover a ton of aborted changes that have no effect, so we strip those out.

By the time we've finished we have a much smaller collection of files that have been changed from Zen Cart's core code and a list of add-on mods.

Then we check whether the mods have versions compatible with the latest version of Zen Cart, and if not assess whether that's a problem. Occasionally we have to upgrade a mod ourselves to avoid it blocking the upgrade, but that's extra cost for the client so we try to avoid it.

Next step is to compare the files containing custom changes that haven't been thrown away to the current version of Zen Cart. If a file has changed in core Zen Cart it's usually best to re-apply the changes to new version of the file as that way the file's current version control stamping is captured (and of course we document those changes and their purpose).

Templates are generally much easier to work with, even when completely botched, than functional changes, as they can generally be segregated using the override system.

When we've finished, we merge the files from the latest version of the add-ons, with those for custom changes and then overlay the result onto a clean install of the latest version of Zen Cart and start testing.

It's really not a lot different from doing a normal upgrade, but unless you keep a clear focus on the goal of each step, it is very easy to get lost.

The biggest challenge is usually working out what the hell odds and ends of changed code are meant to do and what to do about them. It gets easier over time and as you get a better feel for and knowledge of Zen Cart (we've been doing this for six years and so have the advantage of knowing it pretty well) and I suspect that this will prove to be the most challenging aspect of the work for you.

But good luck and remember that this forum is here to help you.

[Fehfeh]

Thank you for constructive answers. I slapped my superiors head around with a large trout and made him find out what he could about alterations to the core functionality and it was good news. As far as he could remember, and discover in his old e-mails, there were just a few custom-mods, done by professionals, from which we still have free support. The mods I have installed after I started working here I have well documented so they are easy to reinstall.

We then agreed that I should start over from scratch and rebuild the whole thing so we can strip out all the unnecessary things. Another question arised immediately and that is what to export from the existing DB, and what to leave "stock" apart from the most obvious things as order/admin/customer data and products.

[Digiwinkel]

If you read the 'comments' of the various Dbase parts thorougly, you will be able to just insert the bits and pieces you want/need from your 'old' Dbase to your new Dbase.

[DrByte]

If you read the 'comments' of the various Dbase parts thorougly, you will be able to just insert the bits and pieces you want/need from your 'old' Dbase to your new Dbase.

A much more correct statement is this:

For your upgrade, you simply use the same database as you have today. For your staging area, simply make a copy of the entire database, and then run zc_install to upgrade that database to the new version's structure. This is all documented in the Detailed Section of the upgrade documentation. www.zen-cart.com/upgrade

TO BE CLEAR: DO NOT HACK OUT SELECTED SECTIONS OF DATABASE CONTENT. TAKE THE ENTIRE DATABASE. The only exception to this would be if you are an highly experienced database engineer and know EXACTLY what you're doing with EVERY one of the almost 100 database tables and ALL of the inter-connected relationships between every one of them.

[Fehfeh]

Thank you for the replies. We settled on doing a fresh install of 1.3.9h (not upgrading to 1.50 just yet) using the existing stores DB and found a simple template as a starting point of building a new one.