Upgrading a very old installation?

[sunyata]

I have a potential client that is asking me to upgrade their web store that is running both Joomla and Virtuemart v.1.0.12. I setup a version of the server running locally and read through recommended upgrade steps that I found here on the forum -  and didn't make it farther than getting Virtuemart to v1.1.5 before the custom templates blew apart. I am not a Joomla developer, but feel pretty confident that I can coax the database migrations necessary to get the site current. But I don't feel like I have the first idea about dealing with the template changes that are already happening , and I suspect will continue to happen on the way to VM 2.0.12.

What I am wondering is, if this upgrade is possible without a new set of templates, or does it make more sense to start from scratch? Is there a recommended way of getting an old installation like this to the 2.0+ world that I am missing?

Any advice would be greatly appreciated.

[jenkinhill]

The structure of Joomla 1.0, 1.5 and 2.5 templates are very different, as is the output view so yes, you do need new templates. However, the only one you need to worry about is the last one (J2.5 with latest VM version) as that will be the final working version. The migration process itself involves database changes only (plus moving product/category images for VirtueMart) not the template structure.

[sunyata]

The structure of Joomla 1.0, 1.5 and 2.5 templates are very different, as is the output view so yes, you do need new templates. However, the only one you need to worry about is the last one (J2.5 with latest VM version) as that will be the final working version. The migration process itself involves database changes only (plus moving product/category images for VirtueMart) not the template structure.

Thanks for the response. That is interesting - I wonder why I'm seeing the front page of the store break when I go from vm 1.0.12 to 1.1.5? Are you thinking I should just get the data current and then deal with the breakage and the templates once I am there?

[jenkinhill]

If the backend shows products etc are there then just go on to the next version(s). For me the change in Joomla versions takes longer to sort out than VirtueMart.