Custom Validator Function for AJV

Table of contents

1. A running example

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It is possible to add custom asynchronous validation functions using the asyncValidatorFunction keyword.

A running example

If there is a model called example, the attribute id in the model would be validated. Only if its value is "1" does it pass validation.

Implementing this takes two steps:

1. Find the file example.js in the validations folder.
2. Add the asyncValidatorFunction keyword and the corresponding asynchronous validation function for attribute id in validatorSchema.

Example code:

example.prototype.validatorSchema = {
  "$async": true,
  "properties": {
    "id": {
      "asyncValidatorFunction": async function(data) {
        if (data === "1") {
          return true
        } else {
          return new Promise(function(resolve, reject) {
            return reject(new Ajv.ValidationError([{
              keyword: 'asyncValidatorFunction',
              message: `${data} is not 1`
            }]))
          })
        }
      }
    }
  }
}

See also Customize Zendro for how this fits into the broader customization workflow.