feat($core): custom data block

packages/@vuepress/core/lib/internal-plugins/dataBlock/index.js

@@ -0,0 +1,26 @@
+module.exports = () => ({
+  name: '@vuepress/internal-data-block',
+
+  chainWebpack (config) {
+    config
+      .module
+        .rule('data-block')
+          .resourceQuery(/blockType=data/)
+          .use('date-block-loader')
+            .loader(require.resolve('./loader.js'))
+  },
+
+  enhanceAppFiles () {
+    return [{
+      name: 'data-block',
+      content: `
+  export default ({ Vue }) => { Vue.mixin({
+    computed: {
+      $dataBlock() {
+        return this.$options.__data__block__
+      }
+    }
+  }) }`.trim()
+    }]
+  }
+})

packages/@vuepress/core/lib/internal-plugins/dataBlock/loader.js

@@ -0,0 +1,9 @@
+module.exports = function (source, map) {
+  this.callback(
+    null,
+    `export default function (Component) {
+      Component.options.__data__block__ = ${source.trim()}
+    }`,
+    map
+  )
+}

packages/@vuepress/core/lib/prepare/AppContext.js

@@ -115,6 +115,7 @@ module.exports = class AppContext {
       .use(require('../internal-plugins/layoutComponents'))
       .use(require('../internal-plugins/pageComponents'))
       .use(require('../internal-plugins/transformModule'))
+      .use(require('../internal-plugins/dataBlock'))
       // user plugin
       .useByPluginsConfig(this.cliOptions.plugins)
       .useByPluginsConfig(this.siteConfig.plugins)