| 1 | # Mixin Polyfill |
| 2 | |
| 3 | Mixins will have built-in support in a future version of CiviCRM (vTBD). However, |
| 4 | for an extension to use a mixin on an older version of CiviCRM, it should |
| 5 | include the polyfill ([mixin/polyfill.php](../mixin/polyfill.php)). |
| 6 | |
| 7 | ## Usage |
| 8 | |
| 9 | The polyfill will be enabled in `civix` (vTBD). To activate the polyfill in |
| 10 | a bespoke extension (`myext`, `org.example.myextension`), copy `mixin/polyfill.php`. |
| 11 | Load this file during a few key moments: |
| 12 | |
| 13 | ```php |
| 14 | function _myext_mixin_polyfill() { |
| 15 | if (!class_exists('CRM_Extension_MixInfo')) { |
| 16 | $polyfill = __DIR__ . '/mixin/polyfill.php'; |
| 17 | (require $polyfill)('org.example.myextension', 'myext', __DIR__); |
| 18 | } |
| 19 | } |
| 20 | |
| 21 | function myext_civicrm_config() { |
| 22 | _myext_mixin_polyfill(); |
| 23 | } |
| 24 | |
| 25 | function myext_civicrm_install() { |
| 26 | _myext_mixin_polyfill(); |
| 27 | } |
| 28 | |
| 29 | function myext_civicrm_enable() { |
| 30 | _myext_mixin_polyfill(); |
| 31 | } |
| 32 | ``` |
| 33 | |
| 34 | ## Limitations / Comparison |
| 35 | |
| 36 | The polyfill loader is not as sophisticated as the core loader. Here's a comparison to highlight some of the limitations: |
| 37 | |
| 38 | | Feature | Core Loader | Polyfill Loader | |
| 39 | | -- | -- | -- | |
| 40 | | Load mixins from files (`mixin/*.mixin.php`) | Yes | Yes | |
| 41 | | Load mixins from subdirectories (`mixin/*/mixin.php`) | Yes | No | |
| 42 | | Read annotations from mixin files (eg `@mixinVersion`) | Yes | No | |
| 43 | | Activation - How does it decide to activate a mixin? | Read `info.xml` | Read `mixin/*.mixin.php` | |
| 44 | | Boot cache - How does it store boot-cache? | All boot-caches combined into one file | Each extension has separate boot-cache file | |
| 45 | | Deduplication - If two extensions include the same mixin, then only load one copy. | Yes | Partial - for exact version matches. | |
| 46 | | Upgrade - If two extensions include different-but-compatible versions, always load the newer version. | Yes | No | |