Plugin Compilation and Packaging in the Aura Framework: Resource Sharing, AAPT and Gradle Aura-Plugin Solutions

Plugin compilation and packaging is a crucial task in modular development, and the Aura framework has explored various approaches, encountering challenges especially in handling shared resources and resource grouping.

Shared Resource Sharing – Shared resources, including images, layouts, styles, and code, are placed in the host project as JAR or AAR files. Plugins can directly use them, and Aura ensures consistent resource IDs by maintaining the host's public.xml file.

Before Gradle 1.3.0, public.xml could be placed under /res/values/; after that version it must be copied to the merged build directory via a Gradle script.

Android resource IDs consist of PackageId, TypeId, and EntryId. To avoid conflicts, Aura assigns each plugin a unique PackageId in the stable range 0x21‑0x7E, while alternative EntryId manipulation is considered too complex.

The compilation goal is to reference shared resources during build but not package them, keeping the final plugin size minimal.

Two Implementation Schemes

AAPT Scheme – Modifies the Android build tool AAPT to accept a packageId parameter, provides shared resources as JAR (using provided) or AAR (extracting classes.jar), and passes public.xml to fix IDs.

Pros: Near‑native compilation stability. Cons: Requires multiple AAPT versions for different Android releases, cross‑platform builds, and manual replacement of the tool.

Gradle Aura‑Plugin Scheme – Based on the Small open‑source solution, it hooks into key Gradle tasks without modifying AAPT. It processes JAR/AAR, classes, resources, package IDs, assets, native .so files, AndroidManifest.xml, public.xml, and R.class using Gradle transforms and resource‑arsc parsing.

Advantages: Simple configuration in build.gradle, cross‑platform support, no AAPT changes. Disadvantages: Slightly lower stability due to manual interference, and the need to keep up with rapid Gradle version updates.

Conclusion – Both schemes can handle shared resources and produce small, independent plugin packages. Currently Aura uses the Gradle aura‑plugin scheme as the primary solution, with the AAPT scheme kept as a fallback.

— JD.com Mobile Technology Team