SOMOD Extensions

---

Extend the working of the SOMOD toolset using the extensions. An Extension is a SOMOD module having an extension.ts file at the root of the project.

Extension file structure

project-root
    |
    +-- node_modules                         --+
    |       +-- module-a                       |
    |               +-- build/                 | FROM DEPENDENCIES
    |                     +-- extension.js     |
    |                                        --+
    |
    |
    +-- build/                               --+
    |     +-- extension.js                     | BUILD OUTPUT
    |                                        --+
    |
    +-- extension.ts                         --  SOURCE

During the build stage, SOMOD compiles extension.ts into build/extension.js. While preparing, SOMOD loads and applies extensions from all the installed modules.

Content of Extension

Provide the following named exports from the extension.ts file to modify the behavior of the SOMOD tool. Each named export is optional.

Hooks

Hooks are the custom functions called during the build and preparation phase.

Learn more about SOMOD CLI in its dedicated chapter here

• prebuild

  import { IContext } from "somod";
  export const prebuild = async (context: IContext) => {
    // do pre-build actions
  };
  

  • prebuild hooks are called after the validation and before the build tasks during the somod build command.
  • prebuild hooks are called in the order of module dependency from parent to child. For example, if extension A depends on extension B, prebuild of A is called before prebuild of B.

• build

  import { IContext } from "somod";
  export const build = async (context: IContext) => {
    // do build actions
  };
  

  • build hooks are called after the build tasks during the somod build command.
  • build hooks are called in the order of module dependency from child to parent. For example, if extension A depends on extension B, the build hook of B is called before the build hook of A.

• preprepare

  import { IContext } from "somod";
  export const preprepare = async (context: IContext) => {
    // do pre-prepare actions
  };
  

  • preprepare hooks are called before the prepare tasks during the somod prepare command.
  • preprepare hooks are called in the order of module dependency from parent to child. For example, if extension A depends on extension B, preprepare of A is called before preprepare of B.

• prepare

  import { IContext } from "somod";
  export const prepare = async (context: IContext) => {
    // do prepare actions
  };
  

  • prepare hooks are called after the prepare tasks during the somod prepare command.
  • prepare hooks are called in the order of module dependency from child to parent. For example, if extension A depends on extension B, the prepare hook of B is called before the prepare hook of A.

Namespaces

Extensions can provide namespaces using namespaceLoader

Learn more about SOMOD Namespace in its dedicated chapter here

• namespaceLoader

  import { NamespaceLoader } from "somod";
  export const namespaceLoader: NamespaceLoader = async (module, context) => {
    // return namespaces for the provided module
  };
  

Keywords

Extend the parsing of ui/config.yaml and serverless/template.yaml using extension keywords.

Learn more about how SOMOD processes yaml files in its dedicated chapter here

• uiConfigKeywords

  import { KeywordDefinition } from "somod";
  export const uiConfigKeywords: KeywordDefinition[] = [
    // keywords with validator and processor functions
  ];
  

• serverlessTemplateKeywords

  import { KeywordDefinition } from "somod";
  export const serverlessTemplateKeywords: KeywordDefinition[] = [
    // keywords with validator and processor functions
  ];
  

Serverless Functions

Extend the Serverless functions with the following properties from the extension.

Learn more about SOMOD's serverless features here

• functionLayers

  Defines the layers to be applied to serverless functions from all installed modules

  export const functionLayers: string[] = [
    // Resource Ids of the layers declared in serverless/template.yaml of this project
  ];
  

• functionMiddlewares

  Defines the list of middleware to be applied to serverless functions from all installed modules

  export const functionMiddlewares: string[] = [
    // Resource Ids of the middlewares declared in serverless/template.yaml of this project
  ];
  

Now we have understood the main concepts of SOMOD, let us explore the SOMOD CLI in the next chapter