[QBS] Heads up: Deprecating the Transformer item

[Christian Kandeler]

Good morning*,

right from the beginning, the Transformer item was an odd one, its 
inputs being file paths instead of tags. As the Rule item evolved, 
Transformers fell more and more behind, and when we introduced "dynamic" 
rules, they stopped playing well with the rest of qbs and probably 
should have been removed at that point.
Well, better late than never: We are deprecating Transformers for qbs 
1.6 and we will remove support for them entirely in qbs 1.7.
Here's the transition guide:
     Case 1: Your Transformer has inputs, i.e. it looks like this:
             Transformer {
                 inputs: ["somefile.txt"]
                 Artifact { ... }
                 ...
                 prepare: { ... }
              }
              Instead, give "somefile.txt" the tag "sometag" and now
              write:
              Rule {
                  inputs: ["sometag"]
                  Artifact { ... }
                  ...
                  prepare: { ... }
              }
              That's it. You can do that right now, as a Transformer
              was never required for this sort of thing.
     Case 2: Your Transformer has no inputs, i.e. it looks like this:
             Transformer {
                 Artifact { ... }
                 ...
                 prepare: { ... }
             }
  	    Instead, write this:
             Rule {
                 multiplex: true
                 Artifact { ... }
                 ...
                 prepare: { ... }
             }
             Note: This is *not* possible using a current release,
             as rules with no inputs will only be supported from qbs 1.6
             onwards (the feature is already available in the master
             branch, though). We recommend you do this kind of change
             soon after qbs 1.6 is released.


Thank you for your attention,
Christian


*local time of day might differ depending on location