allow referencing a channel type in the DSL

[sjsf]

in the Thing DSL it is possible to define channels manually.
However, it was not possible so far to reference a binding's
channel type which is defined in the XMLs.

Signed-off-by: Simon Kaufmann simon.kfm@googlemail.com

[maggu2810]

One comment.
As I don't use the DSL much, I would prefer if @kaikreuzer could have a look at, too.

[maggu2810]

I don't know anything about Xtext, but what about channelTypeUID if it.channelType == null (the else branch). It seems to be undefined / null. Is the call to withType okay for a non-defined type?

[sjsf]

Yes, it is. The ChannelBuilder is implemented in a way that setting it to null is the same as not setting it at all.

[sjsf]

And more important, channels don't need to have a ChannelTypeUID at all:

    /**
     * Returns the channel type UID
     *
     * @return channel type UID or null if no channel type is specified
     */
    public ChannelTypeUID getChannelTypeUID() {
        return channelTypeUID;
    }

[kaikreuzer]

Question: Shall we actually also allow overriding (or defining) labels on channels (irrespectively whether they are based on a type or not)? Or is it good enough if people define their default label on the item (which probably suffices). Labels on channels are rather meant for bindings to provide them, so it might not be relevant for the DSL - just asking nonetheless.

[sjsf]

Very good point. If you have a UI where you bind items to channels, you might want to see a nice name (aka label) instead of just the technical id. Therefore I think we should.
I would propose to create a separate PR for it, if that's okay?

[kaikreuzer]

Yes, absolutely!

[kaikreuzer]

Many thanks!