Multiple sites project - WPMU or WP

[Ryan]

... If I got a plugin used on all 5 websites that create new tables in the database, how do I make sure there won't be any conflict between the different sites?

I would guess they would totally glitch with each other unless they "know about" WordPress Mu and so use different table names to compensate.

I believe WP e-Commerce creates tables and it definitely works on WordPress Mu ... http://getshopped.com/. So I assume they're using different table names for each Mu site.

[andreasnrb]

Hmm. I've totally forgot MU support for my table generating plugins. I'll have to add that.

[andrea_r]

Originally Posted by Jeremy
... If I got a plugin used on all 5 websites that create new tables in the database, how do I make sure there won't be any conflict between the different sites?
I would guess they would totally glitch with each other unless they "know about" WordPress Mu and so use different table names to compensate.

They don't have to though. If they are done right, the right table prefix is added to any tables they create.

Cforms11 for example, creates the right tables for each blog, but saves customizations in the one plugin folder. So the current conflict in that plugin means that if one users customizes things for one of their forms, the next user who makes a customization blows it away.

@andreasnb - better to do it sooner than later :)

[Jeremy]

Great, thank you for the info! So basically, all I have to do is try an install of WordPress with the plugins I am interested in using, and check if they create tables with the correct prefix or without? Then I'd know if they are compatible with a multiple blog install? Or is there a list somewhere, that would avoid me having to make a test install? Here are the plugins I am going to use:

• Akismet
• Google XMP Sitemaps
• Disqus Comment system
• Contact form 7 plugin
• Uservoice Widget plugin

That will be all for my base install afaik. Thanks again!

[Ryan]

The only one I think you could have a problem with is Uservoice. The rest are pretty standard (ie: mega popular) plugins so would presumably have had someone provide a patch for Mu support.

If your plugin doesn't support Mu, someone will generally come along with a suitable patch for it.

EDIT: I have no idea what Uservoice is, hence I assumed it wasn't popular.

[andrea_r]

• Akismet - may need license for it, please check their terms. Otherwise, of course it works. (see wp.com)
• Google XMP Sitemaps - don't use the standard one, find one of the MU ones (I usually skip this unless it's been proven that google is skipping posts. On most sites I've dealt with, google eats them up like crazy anyway, without sitemaps. Otherwise, with the default wp one, every single time someone posts anything acros the entire site, it rebuilds the sitemap. Yes, one. oops.)
• Disqus Comment system - works
• Contact form 7 plugin - works. I use it, and even tho one of my blogs is having an isue, it could be user error. ;P
• Uservoice Widget plugin- dunno, but I would guess it does, seeing as it's widget.

Ways to know a plugin isn't working MU:
- it fails to create the tables in the right places. (usually new tables - if it save a new field to places liek the options table, you're usually fine.)
- any option page in the backend fails to save. This means the plugin itself needs to be fixed. See here:
http://wpmututorials.com/how-to/writing-plugins/
http://wpmututorials.com/how-to/option-arrays/

[Ryan]

• Google XMP Sitemaps - don't use the standard one, find one of the MU ones (I usually skip this unless it's been proven that google is skipping posts. On most sites I've dealt with, google eats them up like crazy anyway, without sitemaps. Otherwise, with the default wp one, every single time someone posts anything acros the entire site, it rebuilds the sitemap. Yes, one. oops.)

Weird. I assumed a major plugin like that would work with no problems at all.

[andrea_r]

I'm not sure if anyone (who has worked on an improved version) has sent the code back to the original dev.

Which would be nice & a win-win.

[Jeremy]

Well thank you everyone! That helped me a lot! I think I will go ask my other questions in the WordPress MU forum where others can look for answers!

Thanks again!

[kgraeme]

Weird. I assumed a major plugin like that would work with no problems at all.

Even when a plugin works, there may be better mu-specific alternatives. For instance, with Google Sitemaps, or Google Analytics, are they for each individual blog or for the entire MU install? Do they let the site-admin (super admin) pre-code the api key for user transparency (like we do with Akismet on our enterprise sites, with the correct license) or require/allow each user to enter their own api key?

There's no right answer, just different business needs.