Depressed with CMSs

Drupal seems to be for hobbyists who love to tinker all day and night. It's very hard to get fast, clear answers to issues. The forums here are not very responsive because the "developers community" is split between Drupal and CivicSpace - which is supposedly not a fork, although you'll run into compatibility issues if you try to use modules and themes from one in the other. Starting with Drupal will cost you a lot of time you clearly don't have.

I'm recently writing a module to extend Drupal with newspaper articles, authors and volumes. And I didn't find it that hard to step into Drupal's code.

Escpecially handling the DB, providing forms for user input, introduce custom node rendering, and extending the menu where quite easy. And this usually already is the main part of the work. However, it took me a while to figure out you also need the "menu" hook to tell Drupal your module wants to handle a specific kind of url, like e.g. /vehicles/id :-).

To answer at least a 3 of your questions:

1.) What modules to learn from? For extending nodes to a larger extend than page_example does, I personally took a look at the bookreview module. However, I also found myself diving through the node and taxonomy module quite a lot, since there you'll find some real complex SQL statements.

And I definitly recommend to use a good PHP IDE to trace down code flow, else you will be lost.

2.) One module per node type. I'm not even sure if you are able to define more than one node type in a module. However, having one module will keep your code cleaner. And name the node type the same as the module. I had problems when trying to force a different name.

3.) There's a function watchdog($type, $message, $severity = WATCHDOG_NOTICE, $link = NULL) to log events to the DB. This should do it, I guess

4.) Unfortunately, I don't know anything about image uploading :-(.

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Gerd Riesselmann
www.gerd-riesselmann.net

I don't do complex websites, but here are some modules to look at.
taxonomy to categorize stuff.

Flexinode. This swill let you build custom field types. There is an ecommerce module bundle that may get you some more product flow as well

You mention permissions. You can do it through taxonomy or by node, not both. Depending on How you do your site, taxonomy_access_contorl or node_privacy_by_role may suit you.

For images, I would suggest img_assist, posible in combination with tinyMCE.

You could also write your own node type if you are familier with php. See drupaldocs.org for misc stuff.

Logging has always been sufficient for me, but there are some odules that add some stuff. You may be able to use themn as a basis for increasing what you want.

Whether or not you can come up to speed on Drupal in a timely fashion is an interesting question. I have seen people beat their head, say nasty things in the forums and quit. I have seen people beat their heads for a while and suddenly something clicks and I have seen people that thought Drupal was the most logical thing since sliced bread and just 'got it' right off the bat.

Whether you use it for thi sproject or others, welcome to the community and have fun.

-sp
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Test site, always start with a test site.
Drupal Best Practices Guide -|- Black Mountain

Just a few ideas to address the OP, off the top of my head:

What example modules do you recommend to look at that show manipulation of related database tables (that is a bit more complex than the very basic - and yet still buggy - page_example.module)?

All of 'em. ;-) Drupal is open source, so just grab an existing module that does something similar to what you want and dig into it. I wouldn't underestimate the utility of the example module, either -- it's a good start for learning how to build custom nodes.

Should I implement each object as a seperate module (i.e. Vehicle module, Engine module, etc.) or should I have one module that handles the lot?

I'd say customize it. Write a simple one to get your feet wet (using node_example as a start), then scale as needed. Once you wrap your mind around how Drupal's form callbacks work, it's easy. Flexinode is nice for quick-and-dirty prototyping, but in the long term, IMO it's better to roll your own.

Does the watchdog module allow more fine grained logging types (e.g. Vehicle changes, Engine changes, etc.)? Where should I look for examples on creating log events (e.g. User x changed price on vehicle y)?

Watchdog will log any message you throw at it; just stick watchdog() calls wherever you want. Since it automatically logs the user at the time of the call, all you need is to determine the granularity of the detail you want to capture, and call watchdog() accordingly.

Is there any image upload module out there that is easily used by custom modules to add sets of images to a data strucute? There seems to be a lot of custom image modules, do any allow me to add image uploading for example to my 'Add Vehicle' form in a robust and easy manner, and then allow displaying of those images when displaying the Vehicle node?

If you just want the ability to upload images, associate them with a node, and view them, I'd use the upload module (included as part of the Drupal core component set) with the inline module. If you want to build image galleries and link to them from multiple nodes, then image.module and img_assist would be better fits -- but if your images will be associated with only one parent node (such as engine schematics), then that's probably overkill.

All IMO, anyway. If I were to do the project in the OP, I'd create custom node modules for all the fundamental types (vehicle.module, engine.module, etc.), use the relativity module to build links between them, and use upload.module and inline.module for the images. I'd also create a few different user roles, so the folks using the system wouldn't accidentally stumble into a system administration task and futz something up by mistake.

--R.J.
http://www.electric-escape.net/

This isn't meant to be a Drupal flame, but why use a cms at all? It seems to me that for this type of application you would be much better off starting with CodeCharge (would be perfect), or Dreamweaver, and providing your users with the tools to enter data into their database?

Based on my limited experience you will be forever trying to twist a cms to do what you want, since they aren't designed for this?

1) example modules:

While learning how to program Drupal, I found some of the basic built-in modules extremely helpful.

1. The node module is invaluable, if for no other reason that you have to learn how this module works to really understand how a few of the hooks really work. This is an unfortunately poorly documented process, but if you have a good grasp of OO methodology, it is not too hard to follow. The _nodeapi hook, for example, is ludicrously powerful, but knowing where and when it gets called takes some study.
2. The story module is a great simple module to learn how some of the basics of a node are actually used. The poll module is a good example for looking at a module that uses a custom node extension, and the forum module is as well.
3. The workflow and actions modules are good for implementing process in Drupal. I don't think they're quite at the stage they need to be -- for my site, I had to do quite a bit of work to make them do what I needed to do, but they are worth a look.

2) I believe I would implement the sub-tables as Taxonomy, and if you believe that would confuse the end-user, I would spend my time coding up an alternative interface to the parts that you believe would be confusing. I would probably just hack the taxonomy module, in fact, to do what I want. I realize this is not necessarily accepted practice, because it makes future upgrades difficult, but if you do a good job of localizing your hacks, you should be able to upgrade with a known amount of work. I would do my level best to put as much of it as I could into my custom module, but I don't know, offhand, how much of the taxonomy module would need to be changed to suit your purposes. You may not need much -- it's entirely possible that changes you need to make can simply be changed with theme_ functions. Those are some of the coolest parts of Drupal.

3) The watchdog question has been answered by someone else. You might have to do some work here in order to make certain that your watchdog entries are preserved, as I believe the watchdog only goes back so far. But otherwise I believe it will do what you want.

4) look at the attachment module that comes with Drupal. It does basic image uploading and creates the images as an attachment. It does not do exactly what you want. However, it is an extremely simple module and I believe you can either beat it up so that it does what you want, or you can simply hack the code you need into your own module.

5) the exiting revisioning system is unlikely to be what you want, and I would not look at it. The one that's in Drupal 4.6.3 is broken, and is being replaced in 4.7 anyway, but that version only exists in the CVS version of Drupal. The new one will likely do what you want, though.

6) Date/Time seems to be handled relatively well, but it's pretty simple. I haven't had to do too much work with date/time, but it handles the basics just fine. It does handle timezones quite nicely.

I think Drupal can do what you want it to do. I think you should plan for 2-3 weeks of good solid coding, plus any extra you feel would be necessary to your learning curve, but I think you could end up with a good product, and you would have a lot of good stuff that you could re-use.

Someoned mentioned that you may need a module for paging results: Drupal has paging built-in. (pager_query() and theme_pager() -- look on drupaldocs.org for those) and they're quite powerful. Also, themeable, so if you don't like the default pager output you can easily rewrite it all you like. (I did!))

I wish you all sorts of good luck in your endeavor!

Also, if you have more questions, I will be more than happy to answer them. I often miss the forums, though, the traffic is relatively high and I go through phases of reading/not reading based on how much time I'm spending on a Drupal-related activity that week.