Struggled with this a bit, but thought I'd post my solution here for others to use.
IDX Broker allows for users to wrap their own current website Header & Footer around the IDX content. However, the MODx portion must be coded with absolute paths so as not to conflict with IDXBroker.
Below are the steps I've used to accomplish the blending MODx and IDXBroker.
1. Make a duplicate of your site header and footer chunks, and rename so that you can associate it with IDX
2. Remove
<base href="[[++site_url]]" />
from your Header Chunk.
3. In your header and footer, make all paths to files absolute
4. Make a template page for use with the page that will be your IDXBroker Wrapper. You can just duplicate one of your existing templates, and then update the calls to the header and footer chunks to reflect those for the one created for use with IDX. Make any paths to images or files absolute.
5. Create a Resource. Apply the template you created for IDX. Publish It, but hide from Menus.
6. Update your Wayfinder or pdoMenu call to include &scheme=`full` (This creates full / absolute URLs and will allow users to get out the IDX site and back to your MODx site using the main navigation menu.) You may or may not have this call in a chunk, or it might be right in the template itself. Any links in the main nav that need to go to IDXBroker are done by creating a MODx resource, but making the Resource Type: weblink
7. IDX has instructions for how to call the IDXBroker data to the page. (Basically a couple of lines of code that you insert within your own div wrapper in the body of the template.
