Parameters

The SOMOD Parameters define the configurations for the module. ui/config.yaml and serverless/template.yaml refer to the parameters available in the parameters.yaml.

ui/config.yaml and serverless/template.yaml can refer to the parameters from the current and all dependency modules.

When more than one dependency module has the same parameter defined, the conflict is resolved using the namespaces.

SOMOD build command validates parameters.yaml and generates build/parameters.json. SOMOD prepare command combines parameters from all dependency modules and updates the missing values in the root parameters.json. The prepare command also generates the NextJs and AWS SAM configuration files from parameters.json in the root.

project-root
    |
    +-- node_modules                               --+
    |       +-- module-a                             |
    |               +-- build/                       | FROM DEPENDENCIES
    |                     +--parameters.json         |
    |                                              --+
    |
    +-- build/                                     --+
    |      +-- parameters.json                       | BUILD OUTPUT
    |                                              --+
    |
    +-- parameters.yaml                            --- SOURCE
    |
    +-- parameters.json                            --- PREPARED

There are three parameter files in a module.

• The developer creates the parameters.yaml in the root directory.
• SOMOD build command generates the build/parameters.json from parameters.yaml.
• parameters.json at the root directory contains a JSON object of parameter names and values. SOMOD prepare command uses the values in parameters.json to create .env, next.config.js, and template.yaml.

Anatomy of parameters.yaml

parameters:
  mycomponent.param1: # parameter name
    type: string # parameter schema follows JSON-Schema7 specification
    default: waw
    maxLength: 20
  mycomponent.param2:
    type: email
    default: me@example.com

The parameters.yaml contains one section, parameters

• parameters
  parameters is a map of the parameter name to JSON schema.

  • Parameter name
    The parameter name has the following constraints

    • must contain only the alphabet, numbers, and dots
    • can have a maximum of 128 characters.
    • must start with the alphabet
    • and must have at least one dot

  • Parameter Schema
    Must use the JSON-Schema version 7 specification.

Parameter Name is namespaced. Meaning there should be only one occurance of a parameter name in all installed modules.

In the Next Chapter, let us understand the namespaces in SOMOD.