feat: update documentation

README.md

@@ -19,46 +19,78 @@ In some cases, it is possible to prefetch the static resources of an application
 The prefetch builder generates a `ngxPrefetch.js` file that should be included in the HTML page of the entry point. When run, it dynamically [creates `<link>` tags](https://developer.mozilla.org/en-US/docs/Web/HTTP/Link_prefetching_FAQ) for each static resource (such as JS and CSS files) so that the browser can prefetch them during idle times. This will improve the Page Load Time of the application when it is actually loaded.
 
 ## Prerequisites
-A prerequiste for the script is to have [Angular Service Worker](https://angular.io/guide/service-worker-intro) enabled as it is using the `ngsw.json` from the production build  folder that is generated by the Angular Service Worker. Therefore it will be ran after the build prod.
+A prerequisite for the script is to have [Angular Service Worker](https://angular.io/guide/service-worker-intro) enabled as it is using the `ngsw.json` from the production build  folder that is generated by the Angular Service Worker. Therefore, it will be run after the build prod.
 
 ## Install
 
 ```shell
 npm install -D @o3r/ngx-prefetch
 ```
+OR
+```shell
+ng add @o3r/ngx-prefetch
+```
+> **NOTE:** This library is following the Angular release cycle. For instance, if you are using Angular 13, use a 13.x version of the library:
+>
+> ```shell
+> npm install -D @o3r/ngx-prefetch@13
+> ```
+> OR 
+> ```shell
+> ng add @o3r/ngx-prefetch@13
+> ```
 
-## Builder options
-  - `targetBuild` **Mandatory** The target build where prefetch should be applied. Used for identifying the `outputPath` of the build.
-
-  - `resourceTypes` An object describing the resource types that should be prefetched.
+## Get started
 
-  - `crossorigin` Flag that sets crossorigin attribute on links. If true it will be set for all prefetched resources.
+1. By running the `ng add` command above, the following lines should have been added to the application's `angular.json`:
 
-  - `production` Flag for creating a production (minified) version of the js file or a development one.
+```json
+"generate-prefetch": {
+    "builder": "@o3r/ngx-prefetch:run",
+    "options": {
+        "targetBuild": "app-name:build:production"
+    }
+},
+```
 
-  - `staticsFullPath` By default the prefetched resources are hosted next to the `ngxPrefetch.js` file, on the same server. If it is not the case, you can configure the full path of the resources that will be prefetched. (ex: https://my-web-app.com/path/to/my-app/). It is also possible to set this value by runtime. Instead of setting it in the Builder's options, you can search and replace for `{STATICS_FULL_PATH}` on the server side in order to inject a path.
-## Usage
+> **NOTE:** Additional configuration can be added to the `angular.json` (builder options are described below with an example of full configuration).
 
-[`package.json`]
+2. Then, add a command to the `package.json` to run `generate-prefetch`:
 
 ```json
-    ...
-    "build:prod": "ng build --prod && yarn run generate:prefetch",
-    "generate:prefetch": "yarn app-name:generate-prefetch",
-    ...
+"generate:prefetch": "ng run app-name:generate-prefetch"
 ```
 
-[`angular.json`]
+3. Run the `ng build` command with the `production` configuration. 
+The default configuration of the build command should be `production`, otherwise it should be specified: 
 
 ```json
-"generate-prefetch": {
-    "builder": "@o3r/ngx-prefetch:run",
-    "options": {
-        "targetBuild": "my-app:build:production"
-    }
-},
+...
+"build:prod": "ng build --configuration production",
+...
 ```
 
+4. Run the previously defined `generate:prefetch` command.
+
+## How it works
+
+Please refer to the details on how the ngx-prefetch works [here](docs/HOW_IT_WORKS.md).
+
+## Builder options
+  - `targetBuild` **Mandatory** The target build where prefetch should be applied. Used for identifying the `outputPath` of the build.
+
+  - `resourceTypes` An object describing the resource types that should be prefetched.
+
+  - `crossorigin` Flag that sets the crossorigin attribute on links. If true it will be set for all prefetched resources.
+
+  - `production` Flag for creating a production (minified) version of the js file or a development one.
+
+  - `staticsFullPath` By default the prefetched resources are hosted next to the `ngxPrefetch.js` file, on the same server. 
+  If this is not the case, you can configure the full path of the resources that will be prefetched (ex: https://my-web-app.com/path/to/my-app/). 
+  It is also possible to set this value by runtime. Instead of setting it in the Builder's options, you can search for `{STATICS_FULL_PATH}` and replace it on the server side in order to inject a path.
+
+### Example of full configuration
+
 [`angular.json`: full configuration]
 
 ```json
@@ -77,15 +109,5 @@ npm install -D @o3r/ngx-prefetch
         "production": false,
         "staticsFullPath": "https://my-web-app.com/path/to/my-app/"
     }
-},
-```
-
-## Versioning 
-
-This library is following the Angular release cycle. Angular 13 and onwards is supported.
-
-For instance, if you are using Angular 13, use a 13.x version of the library:
-
-```shell
-npm install -D @o3r/ngx-prefetch@13
+}
 ```

docs/HOW_IT_WORKS.md

@@ -0,0 +1,34 @@
+# How ngx-prefetch works
+
+After adding a service worker to your project, as specified in the [prerequisites](README.md#prerequisites), the modifications include 
+the creation of a service worker configuration file called `ngsw-config.json`, which specifies the caching behaviors. 
+Then the build process creates the manifest file `ngsw.json` in the `dist` folder using information from `ngsw-config.json`.
+
+## Create Angular CLI builder
+
+Before all, if the mandatory options are provided and verified, the production output folder is retrieved.
+Then the creation of the builder consists of four steps:
+
+1. The first step is to read the `ngsw.json` file. This allows to create an array of resources based on the asset groups that have the `installMode` set to `prefetch`.
+2. The second step is to read the prefetch [Mustache](https://mustache.github.io/) template file. This template is rendered in JavaScript using the object of variables that is passed as a parameter.
+3. The third step is to write the prefetch JS script using the previous template.
+4. The fourth step is to create a Compiler by bundling the JS file for usage in a browser using [webpack](https://webpack.js.org/).
+
+When this compiler is run successfully, a new file `ngxPrefetch.js` is created in the production output folder.
+
+## ngxPrefetch.js file
+
+The `ngxPrefetch.js` file contains a list of static resources that the Angular service worker should cache based on the `ngsw-config.json` file.
+The path where these resources are hosted can be defined in the [builder options](README.md#builder-options) otherwise the default path is next to the `ngxPrefetch.js` file, on the same server.
+
+Then, for each resource of type `string`, a link is appended to the html header of the webpage with the following properties:
+* A relationship (`rel`) of type `prefetch`
+* The type of content being loaded (`as`) if possible
+* Possibly the `crossorigin` attribute to indicate whether CORS must be used when fetching the resource
+* The URL of the linked resource (`href`)
+
+Below is an example of the appended link: 
+
+```html
+<link rel="prefetch" as="type-of-content" crossorigin href="url-of-linked-resource">
+```

src/index.ts

@@ -121,7 +121,7 @@ export default createBuilder<PrefetchBuilderSchema>(async (options, context): Pr
       if (err || stats.hasErrors()) {
         resolve({
           success: false,
-          error: `Webpack tanspilation failed. ${err || stats.hasErrors()}`
+          error: `Webpack transpilation failed. ${err || stats.hasErrors()}`
         });
       } else {
         resolve({