observe transform should be usable from pub

[DartBot]

Issue by jmesserly Originally opened as dart-lang/sdk#14888

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quoting siggi to web-ui list:

Almost, but not quite, we should open a bug for this.

By default pub would let you say 'observe' to mean "observe/transformer.dart', but in package:observe this file doesn't exist. Pub let's you specify a specific path, so instead of 'observe' you can say:

transformers:

• observe/transform.dart

However, the file you specify needs to have a plugin API (a transformer with a constructor named .asPlugin). We have these in polymer, but not in observe. You can add one yourself in your package instead:

mypackage/lib/observe_transformer.dart:

class WorkAround extends ObservableTransfomer {
   WorkAround.asPlugin() : super(); }

Then use this instead in your pubspec: transformers:

• mypackage/observe_transformer.dart # skip the 'lib' here, this is like a package: import

[DartBot]

Comment by jmesserly

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Removed Priority-Unassigned label. Added Priority-Medium label.

[DartBot]

Comment by sigmundch

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The proper fix is simple:

• rename observable/transform.dart to obserable/transfomer.dart,
• add the asPlugin constructor to ObservableTransfomer

Then you can just say:

transformers:

• observe

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  Changed the title to: "observe transform should be usable from pub".

[DartBot]

Comment by munificent

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• mypackage/observe_transformer.dart # skip the 'lib' here, this is like a package: import

You don't need the ".dart" there either. :)

[DartBot]

Comment by sigmundch

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FYI, I needed this for another bug fix, so it's coming in soon. See:

https://codereview.chromium.org/63173009/

[DartBot]

Comment by sigmundch

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fix landed in dart-lang/sdk@536f92456dc123ee61f3d268ac0d6cfef22fa625

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Added Fixed label.

[DartBot]

Comment by anders-sandholm

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Removed Library-Observe label. Added Pkg-Observe label.