docs: improve documentation related to File templates feature

apps/generator/docs/file-templates.md

@@ -3,7 +3,11 @@ title: "File templates"
 weight: 140
 ---
 
-It is possible to generate files for each specific object in your AsyncAPI documentation. For example, you can specify a filename like `$$channel$$.js` to generate a file for each channel defined in your AsyncAPI. The following file-template names and extra variables in them are available:
+## Generating files with the Nunjucks render engine
+
+> **Note**: This section applies only to the Nunjucks render engine. For information on using the React render engine, refer to the [Generating files with the React render engine](#generating-files-with-the-react-render-engine) section below.
+
+It is possible to generate files for each specific object in your AsyncAPI documentation using the Nunjucks render engine. For example, you can specify a filename like `$$channel$$.js` to generate a file for each channel defined in your AsyncAPI. The following file-template names and extra variables are available:
 
    - `$$channel$$`, within the template-file you have access to two variables [`channel`](https://github.com/asyncapi/parser-api/blob/master/docs/api.md#channel) and [`channelName`](https://github.com/asyncapi/parser-api/blob/master/docs/api.md#channels). Where the `channel` contains the current channel being rendered.
    - `$$message$$`, within the template-file you have access to two variables [`message`](https://github.com/asyncapi/parser-api/blob/master/docs/api.md#message) and [`messageName`](https://github.com/asyncapi/parser-api/blob/master/docs/api.md#message). Where `message` contains the current message being rendered.
@@ -25,7 +29,7 @@ Schema name is '{{schemaName}}' and properties are:
 {% endfor %}
 ```
 
-With following AsyncAPI:
+With the following AsyncAPI:
 ```
 components:
   schemas: 
@@ -53,15 +57,82 @@ Schema name is 'people' and properties are:
 - id
 ```
 
-### React
+> You can see an example of a file template that uses the Nunjucks render engine [here](https://github.com/asyncapi/template-for-generator-templates/tree/nunjucks/template/schemas).
+
+## Generating files with the React render engine
 
-The above way of rendering **file templates** works for both `nunjucks` and `react` render engines, but `react` also has another, more generic way to render multiple files. It is enough to return an array of `File` components in the rendering component. See the following example:
+The above method of rendering **file templates** only works for the Nunjucks render engine. To use the React render engine, you need to follow a different approach. The React render engine allows for a more generic way to render multiple files by returning an array of `File` components in the rendering component. This can be particularly useful for complex templates or when you need to generate a large number of files with varying content.
+
+### Example 1: Rendering hardcoded files
+
+The following is a simple hardcoded example of how to render multiple files using the React render engine:
 
 ```tsx
+import { File} from "@asyncapi/generator-react-sdk";
+
 export default function({ asyncapi }) {
   return [
     <File name={`file1.html`}>Content</File>,
     <File name={`file2.html`}>Content</File>
   ]
 }
-```
+```
+
+### Example 2: Rendering files based on the AsyncAPI Schema
+
+In practice, to render the multiple files, that are generated from the data defined in your AsyncAPI, you'll iterate over the array of schemas and generate a file for each schema as shown in the example below:
+
+```js
+import { File} from "@asyncapi/generator-react-sdk";
+
+/*
+ * To render multiple files, it is enough to return an array of `File` components in the rendering component, like in following example.
+ */
+export default function({ asyncapi }) {
+  const schemas = asyncapi.allSchemas();
+  const files = [];
+  // schemas is an instance of the Map
+  schemas.forEach((schema) => {
+
+    files.push(
+      // We return a react file component and each time we do it, the name of the generated file will be a schema name
+      // Content of the file will be a variable representing schema
+      <File name={`${schema.id()}.js`}>
+        const { schema.id() } = { JSON.stringify(schema._json, null, 2) }
+      </File>
+    );
+  });
+  return files;
+}
+```
+
+### Example 3: Rendering files for each channel
+
+Additionally, you can generate multiple files for each channel defined in your AsyncAPI specification using the React render engine as shown in the example below:
+
+```js
+import { File, Text } from "@asyncapi/generator-react-sdk";
+
+
+export default function ({ asyncapi }) {
+  const files = [];
+
+  // Generate files for channels
+  asyncapi.channels().forEach((channel) => {
+    const channelName = channel.id();
+
+    files.push(
+      <File name={`${channelName}.md`}>
+        <Text newLines={2}># Channel: {channelName}</Text>
+        <Text>
+          {channel.hasDescription() && `${channel.description()}`}
+        </Text>
+      </File>
+    );
+  });
+  return files;
+}
+```
+The code snippet above uses the `Text` component to write file content to the `.md` markdown file. The `newline` property is used to ensure that the content isn't all rendered in one line in the markdown file. In summary, the code snippet above is a practical guide on generating properly formatted multiline Markdown files for each channel in an AsyncAPI document.
+
+> You can see an example of a file template that uses the React render engine [here](https://github.com/asyncapi/template-for-generator-templates/blob/master/template/schemas/schema.js).