(I'm testing a free cloud Confluence instance at the moment while evaluating documentation systems for replacing my current MediaWiki. Trying to determine what kind of features the platform provides and how I re-implement conveniences that we currently rely on.)
Is there a function in Confluence that can be used like MediaWiki's Template system?
At the most simply level, in MediaWiki you can define a page "Template:Whatever" designed however you wish, with some placeholder text marked up as e.g. {{{{value}}}}. On a different page you can include this template a bit like a Confluence Excerpt but while supplying some text to replace the {{{{value}}}} with, like this:
{{Whatever|value=The text to replace}}
It's very useful for supplying consistent panels of data, for example this simple example from my MediaWiki instance:
{{RAID|mountPoint=/mnt/raid|raidLevel=6|numberOfDrives=11|hotSpares=1|driveCapacity=2 TB|totalCapacity=18 TB}}
This renders as a nice table, contains links to relevant concepts, editing the template causes the display to update wherever it's used etc. The table is inserted into the page in the location of this tag. You can define Categories (similar to Confluence Tags) in the included text to apply to the surrounding page as well. You can get deeply into automatic formatting or processing of the supplied data, but I'm not too worried about that bit for now.
Excerpts do a similar transclusion thing, but only for fixed data. Confluence Templates are more for initial page states.
Can anyone point me in the right direction for implementing this kind of thing in Confluence please?
EDIT: I am looking into custom Macros as they look promising, if a bit fiddly. If anyone knows whether I'm on the right track, please let me know!