apeman-app-validate/lib/create.js

apeman app to do schema validation.

/**
 * apeman app to do schema validation.
 * @function apemanAppValidate
 * @param {object} schema - A json schema object.
 * @param {object} [options] - Optional settings.
 * @param {string} [options.format] - Response format like "json", "xml", etc.
 * @param {string} [options.statusCode=400] - Status code for error response.
 * @param {string} [options.prefix='ap'] - Prefix for response header field.
 * @param {string} [options.namespace='data'] - Name space of data in body.
 * @returns {function} - Defined app function.
 */

'use strict'

const assert = require('assert')

const apemanlocale = require('apemanlocale')
const validateData = require('./validating/validate_data')
const parseData = require('./parsing/parse_data')
const parseErrors = require('./parsing/parse_errors')

/** @lends create */
function create (schema, options = {}) {
  if (!schema) {
    throw new Error('schema is required.')
  }

  let format = options.format
  let statusCode = options.statusCode || 400
  let prefix = options.prefix || 'ap'
  let namespace = options.namespace || '/data/attributes'

  /**
   * Defined app.
   * @function app
   * @param {object} req - Request object.
   * @param {object} res - Response object.
   * @param {function} next - Pass to next handler.
   */
  function app (req, res, next) {
    assert(req.locale, 'req.locale not found. Use "apeman-app-locale" before this.')
    assert(req.body, 'res.body not found. Use "apeman-app-form" before this.')
    assert(res.send, 'res.send not found. Use "apeman-app-send" before this.')
    assert(res.header, 'res.header not found. Use "apeman-app-header" before this.')

    let data = parseData(req.body, namespace)
    let errors = validateData(data, schema, { namespace })
    if (errors) {
      let locale = apemanlocale.locale(req.locale())
      res.statusCode = statusCode
      res.header(`${prefix}-validate`, 'invalid')
      res.send({
        errors: [].concat(errors).map((errors) =>
          app.parseErrors(errors, locale)
        ).reduce((a, b) => [].concat(a, b), []),
        meta: {
          schema
        }
      }, format)
    } else {
      res.header(`${prefix}-validate`, 'valid')
      next()
    }
  }

  Object.assign(app, {
    validateData,
    parseData,
    parseErrors,
    // Description of this app.
    $desc: 'Validate with json schema.'
  })
  return app
}

module.exports = create