feat: add hooks on sitemap generation

Author: oemueller

README.md

@@ -29,6 +29,7 @@
 - [Sitemap Options](#sitemap-options)
 - [Sitemap Index Options](#sitemap-index-options)
 - [Routes Declaration](#routes-declaration)
+- [Hooks](#hooks)
 
 ## Installation
 
@@ -591,6 +592,18 @@ const axios = require('axios')
 }
 ```
 
+
+## Hooks
+
+Hooks are listeners to Nuxt events. [Learn more](https://nuxtjs.org/api/configuration-hooks)
+
+You can register hooks on certain life cycle events.
+
+| Hook  | Arguments  | When  | 
+|---|---|---|
+| sitemap:generate:before  | (nuxt, sitemapOptions)  | Hook on before site generation  |
+| sitemap:generate:done  |  (nuxt) | Hook on sitemap generation finished |
+
 ## License
 
 [MIT License](./LICENSE)

lib/module.js

@@ -39,8 +39,10 @@ module.exports = async function module(moduleOptions) {
 
   // On "generate" mode, generate static files for each sitemap or sitemapindex
   nuxtInstance.nuxt.hook('generate:done', async () => {
+    await nuxtInstance.nuxt.callHook('sitemap:generate:before', nuxtInstance, options)
     logger.info('Generating sitemaps')
     await Promise.all(options.map((options) => generateSitemaps(options, globalCache, nuxtInstance)))
+    await nuxtInstance.nuxt.callHook('sitemap:generate:done', nuxtInstance)
   })
 
   // On "ssr" mode, register middlewares for each sitemap or sitemapindex