Validators Example

In this example I have an app that allows users to add their favourite book. I want to make sure the user is entitled to use this api before the book can be created.

1. Step one create a function

import { ValidatorArgs as Args, SRI, ResponseError } from '@coderpunktech/codedraw-core'
import { Environment, Variables } from '@/context'

export const EntitlementValidator = (args: Args<Environment, Variables>): Promise<void> => {
  const sri: SRI.SRI = args.context.get('sri')!
  const accountId = args.context.get('jwtPayload')!.sub
  const resourceManager: ResourceManager = args.context.get('resourceManager')!
  // leave the identifier empty we only care about the name being defined in this case
  const entitlementSri: SRI.SRI = SRI.build('entitlement', { identifier: '__' })
  const entitlement = await resourceManager.getCollection<any>(entitlementSri).findOne({ account_id: accountId })

  if (!entitlement) {
    throw new ResponseError(403, 'Not entitled')
  }

  return Promise.resolve()
}

2. Step two configure the validator

//...
import { EntitlementValidator } from '@/validators/entitlement.validator'

app.use('*', installSDK({
  /**
   * Configure your custom validators here
   */
  validators: {
    createRecord: {
      book: EntitlementValidator,
    }
  },
}))

This will ensure the validators will run everytime a client will try to create a record of entity type book.

Close down the endpoints and only allow your custom code

import { ValidatorArgs as Args, SRI, ResponseError } from '@coderpunktech/codedraw-core'
import { Environment, Variables } from '@/context'

export const OverridesOnlyValidator = (args: Args<Environment, Variables>): Promise<void> => {
  const sri: SRI.SRI = args.context.get('sri')!

  if (!sri.override) {
    throw new ResponseError(403, 'Only Overrides are allowed')
  }

  return Promise.resolve()
}

This validator will make sure only your custom code will execute for all CRUD requests. To wire it:

//...
import { EntitlementValidator } from '@/validators/entitlement.validator'

app.use('*', installSDK({
  validators: {
    '*': OverridesOnlyValidator,
  },
}))