biz-ops-schema

Schema for biz-ops data store and api. It provides two things:

• yaml files which define which types, properties and relationships are allowed. These are intended to be edited by anybody who wants to add to the things the api models
• a nodejs library for accessing subsets this information

Installation and usage

npm install @financial-times/biz-ops-schema

In production the component should be used in either 'poll' or 'stale' update modes, depending on the type of environment.

The component should be initialised once and once only per application. The component is a singleton, and once initialised, @financial-times/biz-ops-schema can be required multiple times in the application, and will already be hydrated with schema data.

Persistent nodejs process (e.g. heroku)

const { configure, startPolling } = require('@financial-times/biz-ops-schema');
configure({
	baseUrl: process.env.SCHEMA_BASE_URL,
	updateMode: 'poll',
	logger: require('n-logger'), // or whichever logger you prefer
	ttl: 10000, // in milliseconds, defaults to 60000
});

startPolling().then(() => {
	// you can now start your app and use the schema
});

Transient nodejs process (e.g. AWS lambda)

const { configure, refresh } = require('@financial-times/biz-ops-schema');
configure({
	baseUrl: process.env.SCHEMA_BASE_URL,
	updateMode: 'stale',
	logger: require('n-lambda-logger'), // or whichever logger you prefer
	ttl: 10000, // in milliseconds, defaults to 60000
});

// in your function handler
const handler = async event => {
	await refresh();
	// now go ahead
};

Speak to a member of the biz ops team to obtain a suitable value for SCHEMA_BASE_URL.

Local development

When npm linking to test schema changes in an application, set updateMode: 'dev' to retrieve schema files from the local yaml files and disable polling/refersh on stale.

Adding to the schema

See CONTRIBUTING.md

Releasing

Create an appropriate semver tag:

• for additions to the schema release as a patch
• for additions to the api relase as a minor
• breaking changes to the API or changes to the structure of data in the yaml files should be released as major

Release process details

Creating a github tag (1.) triggers a circleci build (2.) which, on success, publishes the schema files to s3 on the path /latest/vX.json (where X is the major version) (3a.), and publishes the javascript library to NPM (3b.). biz-ops-api polls /latest/vX.json (4.) and when an update is detected, it constructs and updated graphQL api, then publishes the schema file to /api/vX.json (5.). biz-ops-admin and other secondary consumers of the data poll /api/vX.json for updates to the schema (6.).

The reasoning behind this solution can be seen in this gist

API

All methods use an internal caching mechanism, whih is flushed whenever the schema updates. For this reason

• it is safe to call these methods many times because the complex transformation of values is only executed on the first invocation
• it is an antipattern to store the result of any invocation in a variable for any non synchronous period of time - this may result in incorrect reading or writing of data

getType(type, options)

Get an object defining the structure of a given type. The following transforms will be executed on the raw yaml data.

• if no pluralName field is defined, it will be generated
• any named stringPatterns will be converted to validation functions

The full object structure returned by getType() can been seen here

options

• withRelationships [default: true]: Include the relationships for the type, expressed as graphql property definitions.
• primitiveTypes [default: 'biz-ops']: Graphql only has 4 primitive types - String, Boolean, Int and Float - whereas the biz-ops ecosystem recognises a richer variety e.g Document, Url. They are stored in the schema as these biz-ops types. Setting primitiveTypes: 'graphql' will output property type names converted to their graphql equivalent. This option shouldn't really be needed by anywhere other than the graphql server
• groupProperties [default: false]: Each property may have a fieldset attribute. Setting groupProperties: true removes the properties object from the data, and replaces it with fieldsets, where all properties are then grouped by fieldset
• includeMetaFields [default: false]: Determines whether to include metadatafields (prefixed with _) in the schema object returned
• useMinimumViableRecord [default: false]: If groupProperties is true, this will put any fields defined as being part of the minimum viable record (see model spec) together in a single fieldset

getTypes(options)

Get an array of objects defining the structure of all types. All options for getType are supported and determine the internal structure of each type. Additionally, the following options can be specified:

• grouped [default: false] - determines whether to return the types as a flat array, or an object grouping types in categories. Each category specifies a label, description and list of types.

getEnums(options)

Retrieves an array of key:value objects defining the acceptable values of an enum

options

• withMeta: wrap the enum in an object which also has metadata about the enum (e.g. 'description'.). In this case, the actual enum options will be in a options property

validateTypeName(typeName)

Validates that a type of the given name exists in the schema

validateCode (typeName, code)

Validates that a code string matches the validation pattern defined for codes for the given type

validatePropertyName ( propertyName )

Validates that a string is a valid name for an attribute (i.e. camelCase)

validateProperty(typeName, propertyName, propertyValue)

Validates that the value of a property for a given type is valid

getGraphQLDefs()

Retrieves graphql defs to be used to power a graphql api

normalizeTypeName

Should be used when reading a type name from e.g. a url. Currently is a noop, but will allow consistent rolling out of more forgiving url parsing in futre if necessary

The methods below are unimplemented

describeGraphqlQuery(query)

Decorates a graphql query with metadata from the schema

describeGraphqlResult(query, result)

describeRestApiResult(type, result, options)