Expression into Indirect Tag Binding

[pturmel]

@jlandwerlen

There is nothing wrong with using tag().

Ah, but there is. It simply runs slower, because expressions built around it have to completely execute, even if only one little piece changes, and even if a given change wouldn't yield a change in the output. Totally aside from the (fixed?) bugs in its implementation in v8.0.

Nesting Not Allowed while using Properties in a Template to turn on a Light

Yes, there is. If the items that comprise your tagpath are updated, even if yielding the same result path, the entire expression containing the tag() function will have to execute. With indirect binding, this doesn’t happen. The strings themselves have to be reconstructed every time, even if not changing, slowing down the final expression execution. There are a few cases with computed gateway tags where the tag() expression is the only good way to do indirection, and the dynamic stuff above…

Gateway expression tags are the only place the tag() expression function makes sense.