# Adopting Photon (4.8) Mechanisms and APIs

This section describes changes that are required if you are trying to change your 4.7 plug-in to adopt the 4.8 mechanisms and APIs.

1. Direct usages of Apache Batik CSS should be upgraded
2. Pre-built Lucene indexes should be updated

## 1. Direct Usages of Apache Batik CSS Should Be Upgraded

What is affected: Clients directly using Apache Batik CSS bundles version `1.8.0`.

Description: Due to security vulnerabilities, we have updated the Apache Batik bundles used by Eclipse Platform to version `1.9.0`. Previously it was using version `1.8.0`. Clients that were making direct use of the Apache Batik CSS APIs version `1.8.0` should upgrade their code to work with version `1.9.0`. Other clients should not be affected. See Apache Batik website for details.

Action required: Clients should:

- Upgrade their code to work with Apache Batik CSS version `1.9.0`

## 2. Pre-built Lucene Indexes Should Be Updated

What is affected: Clients supplying pre-built Lucene help indexes.

Description: We have updated the Apache Lucene search engine to Lucene 7.0.0. This means that the indexes built with 6.1.0 will not be readable anymore. See Lucene Change Log for details.

Action required: Clients should:

- Re-build their indexes with Lucene 7.0.0 and supply them as before