I am working on a rough estimate for migrating multiple sites from Drupal 7 to Backdrop. Our agency has quite a few sites (upwards of 10, I think), built on a similar platform in Drupal 7, with fairly typical configuration (includes Panels). Backdrop seems like a great fit for these sites. 

I have read through the documentation on migrating from Drupal 7, and updating themes. I have a few questions about migrating specific things:

  • Our themes are usually based on Adaptive Theme - what do I need to do about that? Will we need to port it? I'm not sure what might happen if we just take out the base theme...
  • Is there a migration path from Drupal 7 Panels to Backdrop layouts? Or do we have to rebuild these ?
  • I can't find a solution for Field Collection - what will happen with these? I'm not sure how extensively they are used in our projects anyway. Will they migrate? 
  • Things like Mailchimp and Google analytics - will the configuration for these migrate or do we need to re-configure? 

That's all for now. TIA!


Personally, I can't answer all these questions. But, I can offer a few resources. 

Next Tuesday we are having a Virtual User Group and Jen Lampton will be doing a live demo of upgrading a site from Drupal 7 to Backdrop CMS.

The day after, on Wednesday. We're having open office hours and taking questions on Drupal 7 to Backdrop CMS upgrades/migrations. 

A few months ago, Jen Lampton did a demo of porting a Drupal 7 theme to Backdrop CMS that is available here:

BWPanda's picture
  • If you migrate without your base theme, you'll lose whatever things your sub-theme inherits from it. These things could include styling, theme functions, settings, etc. I think you can either post Adaptive Theme, or create a new theme in Backdrop (maybe that looks the same as your current one but is a stand-alone theme, or a sub-theme of an existing Backdrop one.
  • Based on https://github.com/backdrop/backdrop-issues/issues/3680 I'd say that there isn't (yet) a migration path from Panels. These will likely have to be setup from scratch in Backdrop.
  • I believe Paragraphs is the recommended replacement for Field Collection. I have a D7 site I need to migrate to Backdrop that uses Field Collection. My plan was to convert them to Paragraphs in D7 first using something like https://www.mtech-llc.com/blog/ada-hernandez/migration-field-collection-... (but adapted for D7), though I'm yet to look into this properly...
  • Mailchimp and Google Analytics should have upgrade paths, check their respective README files and/or issue queues for more details though. I tried using Mailchimp recently and found it broken. I'm not sure how much work is required to get it working...
jenlampton's picture

Our themes are usually based on Adaptive Theme - what do I need to do about that? Will we need to port it? I'm not sure what might happen if we just take out the base theme...

I also have a handful of D7 sites that were using Adaptive Theme. In my case, the only reason I was using Adaptive Theme was to get the responsive behavior, and this is something Backdrop already includes in core, thanks to the layouts system. 

You could have the theme do exactly what it did in Drupal 7, which would leave the work of porting your sub-themes to a minimum. (This is probably what I'd do first, to get everything working as quickly as possible). This port would likely involve creating a template file to override each layout, replacing the bootstrap grid system from core with Adaptive Theme's "way" instead. 

Once this was working, I might also try to remove the Adaptive Theme "way", and use what's already in Backdrop core instead. It might be possible to do so in a way that your sub-themes are unaffected. It really depends how much your sub-themes are doing, and where (which HTML elements are targeted).

I wonder how much of Adaptive Theme would be left without the "Adaptive" bit? Last I checked, there was a lot of other stuff going on in the theme too, and I wonder how the other theme settings would translate.


jenlampton's picture

One more thought...

For simpler sites/themes, I've done a few ports where I built a new theme from scratch as follows:

  1. Put everything on the page in the same place it was on the existing site (build new layouts that match previous panels)
  2. Inspect HTML/CSS for an element on the existing site using a browser
  3. Copy the CSS from the existing site for that element
  4. Inspect HTML/CSS on the new site using a browser, find a matching element
  5. Paste the CSS into the new theme, using the selector for the new element

I wouldn't recommend doing this for complex sites that don't adhere to consistent patterns, or extremely detailed themes. 

It worked nicely for me on this site: http://www.cavallostables.com 

Hi Megan,

This might sound odd…

Would you consider letting me do one of your site conversions for free?

# # #

Ref: https://forum.backdropcms.org/forum/data-migration-d7-backdrop

Basically I want this for in-house training, and I’ll be upfront, we don’t migrate the way other people do.  I’d need from you

- Your current Drupal site, and
- A completely built, new, empty, Backdrop site.

Just a thought.

Internet Design Alliance, owner


Thanks so much for your responses, Jen! It's hard for me to tell what all AT is doing in these themes - I didn't build them myself. AT also has an outdated way of loading responsive CSS hat would have to be changed. Hard to know what else would be required without actually doing the work!

Michael - thanks for the offer, but we're currently just evaluating our options. I need to come up with a rough estimate at this point to present to the clients.