docs: additions and improvements to modules and DML documentation (#7854)

* docs: additions and improvements to modules and DML documentation * small wording fix
2024-07-01 10:26:40 +03:00
parent 72f7500c84
commit b62f23ea00
7 changed files with 66 additions and 11 deletions
@@ -14,8 +14,6 @@ So, resources in the module, such as services or loaders, can only resolve other

 - `logger`: A utility to log message in the Medusa application's logs.

-{/* TODO add other relevant resources, such as event bus */}
-
 ---

 ## Resolve Resources
@@ -0,0 +1,32 @@
+export const metadata = {
+  title: `${pageNumber} Module Isolation`,
+}
+
+# {metadata.title}
+
+In this chapter, you'll learn about how modules are isolated, and what that means for your custom development.
+
+<Note title="Summary">
+
+- Modules can't access resources, such as services, from other modules.
+- You can use Medusa's tools, explained in the next chapters, to extend modules or implement features across modules.
+
+</Note>
+
+## How are Modules Isolated?
+
+A module is unaware of any resources other than its own, such as services or data models. This means it can't access these resources if they're implemented in another module.
+
+For example, your custom module can't resolve the Product Module's main service or have direct relationships from its data model to another module's data model.
+
+---
+
+## Customize and Implement Features Across Modules
+
+In your Medusa application, you want to implement features that span across modules, or you want to extend existing modules to add new features.
+
+For example, you want to extend the Product Module to add new properties to the `Product` data model.
+
+Medusa provides the tools to implement these use cases while maintaining isolation between modules.
+
+The next chapters explain these tools and how to use them in your custom development.
@@ -73,7 +73,7 @@ export async function GET(

  const query = remoteQueryObjectFromString({
    entryPoint: "my_custom",
-    fields: ["id", "test"],
+    fields: ["id", "name"],
  })

  res.json({
@@ -172,3 +172,24 @@ For example, the following methods are generated for the code snippet above:
 Except for the `retrieve` method, the suffixed data model's name is plural.

 </Note>
+
+### Using a Constructor
+
+If you implement the `constructor` of your service, make sure to call `super` passing it `...arguments`.
+
+For example:
+
+```ts highlights={[["8"]]}
+import { MedusaService } from "@medusajs/utils"
+import MyCustom from "./models/my-custom"
+
+class HelloModuleService extends MedusaService({
+  MyCustom,
+}){
+  constructor() {
+    super(...arguments)
+  }
+}
+
+export default HelloModuleService
+```