Merge pull request #14 from yoichiro/optimization-of-loading-pertials

Add a new option to optimize a partial files registration.

README.md

@@ -71,6 +71,7 @@ This plugin can be configured with the following options:
 
 * `templateFileExtension` (string) - Specifies the extension of Handlebars template files. Defaults to `hbs` if omitted.
 * `partialDirectoryPath` (string) - Specifies the path to the directory containing partial template files to be included in Handlebars template files. If omitted, partial template files are not registered.
+* `optimizePartialRegistration` (boolean) - Set to true to optimize the partial registration. This option is effective only when `partialsDirectoryPath` is set. If omitted, the plugin does not optimize the partial registration. If true, the plugin does not register the partials that are already registered.
 * `compileOptions` (object) - Specifies the options to be passed to the Handlebars compiler. If omitted, the default options are used.
 
 These options can be specified as arguments to the `handlebarsPlugin` function. Below is an example that specifies `handlebars` as the template file extension and `templates/partials` as the directory containing partial template files.
@@ -85,7 +86,8 @@ export default defineConfig({
   plugins: [
     handlebarsPlugin({
       templateFileExtension: 'handlebars',
-      partialDirectoryPath: path.resolve(__dirname, 'templates', 'partials')
+      partialDirectoryPath: path.resolve(__dirname, 'templates', 'partials'),
+      optimizePartialRegistration: true,
     })
   ]
 });

integration/partials/sub/sub.handlebars

@@ -0,0 +1 @@
+<i>This is a partial in the sub directory.</i>

integration/templates/template.handlebars

@@ -1,6 +1,7 @@
-<section>
-    <h3>Hello, {{ name }}!</h3>
-    {{> message}}
-</section>
-
-{{> footer}}
+<section>
+    <h3>Hello, {{ name }}!</h3>
+    <p>{{> message}}</p>
+    <p>{{> sub/sub }}</p>
+</section>
+
+{{> footer}}

integration/vite.config.ts

@@ -8,6 +8,7 @@ export default defineConfig({
     handlebarsPlugin({
       templateFileExtension: '.handlebars',
       partialsDirectoryPath: resolve(__dirname, 'partials'),
+      optimizePartialRegistration: true,
     }),
   ],
 });

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@yoichiro/vite-plugin-handlebars",
-  "version": "1.2.0",
+  "version": "1.3.0",
   "author": {
     "name": "Yoichiro Tanaka",
     "email": "yoichiro6642@gmail.com",

src/index.ts

@@ -60,6 +60,13 @@ export type HandlebarsPluginOptions = {
    * If omitted, the plugin does not load and compile partial Handlebars files.
    */
   partialsDirectoryPath?: string;
+  /**
+   * Set to true to optimize the partial registration.
+   * This option is effective only when `partialsDirectoryPath` is set.
+   * If omitted, the plugin does not optimize the partial registration.
+   * If true, the plugin does not register the partials that are already registered.
+   */
+  optimizePartialRegistration?: boolean;
   /** The compile options for the Handlebars compiler. */
   compileOptions?: CompileOptions;
 };
@@ -86,7 +93,8 @@ export default function handlebarsPlugin(
         id,
         templateFileExtension,
         options.partialsDirectoryPath,
-        options.compileOptions
+        options.compileOptions,
+        options.optimizePartialRegistration
       );
       return {
         code: transformed,

src/internal.ts

@@ -60,7 +60,8 @@ export const transform = (
   _id: string,
   templateFileExtension: string,
   partialsDirectoryPath: string | undefined,
-  compileOptions: CompileOptions | undefined
+  compileOptions: CompileOptions | undefined,
+  optimizePartialRegistration: boolean | undefined
 ): string => {
   const partialMap = getPartialMap(
     templateFileExtension,
@@ -72,9 +73,12 @@ export const transform = (
 import Handlebars from 'handlebars/runtime';
 
 ${Object.entries(partialMap)
-  .map(
-    ([name, content]) =>
-      `Handlebars.registerPartial('${name}', Handlebars.template(${content}));`
+  .map(([name, content]) =>
+    optimizePartialRegistration
+      ? `if (Handlebars.partials['${name}'] === undefined) {
+  Handlebars.registerPartial('${name}', Handlebars.template(${content}));
+}`
+      : `Handlebars.registerPartial('${name}', Handlebars.template(${content}));`
   )
   .join('\n')}
 export default Handlebars.template(${precompiled});`;