is there any scenario where `dependOnNewChanges` would be fa

Question

is there any scenario where `dependOnNewChanges` would be false

Ting-Yuan Huang · Answer

Yes For example in java kapt s world no outputs of an isolating processor depend on new changes

Zac Sweers · Answer

could you unpack that a bit more

Ting-Yuan Huang · Answer

It is a flag to specify whether the output being created should depend on new changes It is not whether this processor should depend on new changes because the latter is always true In isolating processors each output file has exactly one originating source So if this source isn t changed or affected for some reason this output is up to date

Zac Sweers · Answer

what s an example of a case where changes to the file wouldn t want to cause a regenerated file

Zac Sweers · Answer

struggling to wrap my head around this

Ting-Yuan Huang · Answer

If a file is changed then it ll always be reprocessed and corresponding files are always regenerated `dependsOnNewCHanges` means new files or changes in other files

Zac Sweers · Answer

hmm ok I think I had my thinking flipped

Ting-Yuan Huang · Answer

Maybe we should rename it to `dependsOnNewFiles`

Zac Sweers · Answer

possibly Does that exclude new files that would normally otherwise qualify for processing if they contain relevant annotations

Ting-Yuan Huang · Answer

Yes If an output doesn t `dependOnNewFiles` it and its inputs has a chance to be skipped Any outputs depending on new files will cause their inputs to be marked as dirty

Zac Sweers · Answer

gotcha So by default it should really be `false` in most cases

Ting-Yuan Huang · Answer

For isolating cases yes For aggregating cases the flag should be true So there is no default value for that parameter

Ting-Yuan Huang · Answer

Just to be clear new files or changed files are always subject to reprocessing regardless of their correspondences to outputs

Zac Sweers · Answer

yeah I m confused again sweat smile

Zac Sweers · Answer

I think I just need to see an example of each

Ting-Yuan Huang · Answer

In fact the correspondence is used to propagate dirtyness You may think of outputs as links when propagating dirtyness from source to source

Zac Sweers · Answer

for example with my auto service ksp processor <https github com ZacSweers auto service ksp pull 7> Each service file my reference multiple KSFile If a file changes or a new one is added I d want the processor to re run and regenerate the final source file

Ting-Yuan Huang · Answer

re examples will do thanks for the questions that helped my document a lot slightly smiling face

Zac Sweers · Answer

it s aggregating in normal apt kapt contexts I think but I m not sure what to do in the KSP case

Ting-Yuan Huang · Answer

In this case all files referenced plus `dependsOnNewFiles` should be included because newly added files or changes in some other existing files may cause them to be included in the future

Ting-Yuan Huang · Answer

I mean `dependsOnNewFiles` can be thought of a wildcard referencing new files or changes in all existing files

Zac Sweers · Answer

+1 cool I think I get it now I think I misunderstood earlier and thought that new applicable files would be run regardless of the value

Ting-Yuan Huang · Answer

New applicable files will still be processed regardless of the value It is that outputs that don t `dependsOnNewFiles` won t affect the propagation of dirtyness due to new files Let me try to build an example

Ting-Yuan Huang · Answer

Let s consider sourceA gt outputA sourceB gt outputB when sourceA is changed If outputB depends on new files sourceA and sourceB are reprocessed if outputB doesn t depend on new files sourceA is reprocessed

Ting-Yuan Huang · Answer

Maybe we should change `dependsOnNewFiles` to `aggregating isolating` It is the same idea as in java but the scope is per output rather than entire processor What do you think

Ting-Yuan Huang · Answer

Another example for new file in previous case if sourceC is added then if outputB depends on new files or it is aggregating sourceB and sourceC will be processed if outputB is isolating sourceC will be processed

Zac Sweers · Answer

those examples are a bit too abstract for me

Ting-Yuan Huang · Answer

Let me try again with github s markdown

Zac Sweers · Answer

more practical one Moshi generates one adapter per source class annotated with ` JsonClass generateAdapter = true ` Message kt with `class Message` results in `MessageJsonAdapter` generated later two other files are added One with another json class and another with something unrelated How does that example fit

Ting-Yuan Huang · Answer

`dependsOnNewChanges` should be `false` in this case because each existing output doesn t depend on new information

Zac Sweers · Answer

gotcha

Zac Sweers · Answer

next example

Zac Sweers · Answer

say I have a processor that generates a factory class that references all the JsonClass annotated classes in the compilation so an aggregating processor which one does that use

Ting-Yuan Huang · Answer

`dependsOnNewChang = true` for that relevant outputs

Zac Sweers · Answer

gotcha

Zac Sweers · Answer

yeah I think renaming that would help

Zac Sweers · Answer

any reason not to just match semantics people are familiar with and rename it to `aggregating`

Ting-Yuan Huang · Answer

because it is per output based Or do you mean why not apply that to entire processor

Ting-Yuan Huang · Answer

Anyway we ll rename `dependsOnNewChanges` to `isAggregating`

Zac Sweers · Answer

yeah that s what I was suggesting

Ting-Yuan Huang · Answer

or simply `aggregating`

Ting-Yuan Huang · Answer

Cool thanks for fish food the API slightly smiling face

Zac Sweers · Answer

happy to help +1