rule-validator/lib/ruleValidator.js

Rule-validator is a javascript module based on amanda. And works for node.js and in the browser. It can be very useful if you work with (d)ddd, cqrs, eventsourcing, domain, commands and events, etc.

(function () {

  var tv4,
      __,
      ruleValidator = {};

  if (typeof(module) !== 'undefined' && module.exports) {
    tv4 = require('tv4');
    __ = require('lodash');
    module.exports = ruleValidator;
  } else if (typeof(define) !== 'undefined') {
    define(['amanda', 'underscore'], function (amanda, underscore) {
      tv4 = tv4;
      __ = underscore;
      return ruleValidator;
    });
  } else {
    tv4 = tv4;
    __ = _;
    this.ruleValidator = ruleValidator;
  }

  var ValidationRules = {};
  ValidationRules.prototype = {

    // __validate:__ Use this function validate some data against a rule.
    // 
    // `rules.validate(ruleName, data, callback)`
    //
    // - __ruleName:__ The rule that should be used.
    // - __data:__ The data that should be validated.
    // - __callback:__ `function(err){}`
    validate: function(ruleName, data, callback) {
      if (this[ruleName]) {
        var validation = tv4.validateResult(data, this[ruleName]);
        if (!validation.valid) {
          if (validation.error.subErrors && validation.error.subErrors.length > 0) {
            validation.error.subErrors = __.sortBy(validation.error.subErrors, function(s) {
              return -s.code;
            });
            callback(validation.error.subErrors[0].dataPath + ' => ' + validation.error.subErrors[0].message);
          } else {
            callback(validation.error.dataPath + ' => ' + validation.error.message);
          }
        } else {
          callback(null);
        }
      } else {
        callback(null);
      }
    }
      
  };

  // __extend:__ Use this function to create your rule validator object.
  // 
  // `base.extend(rules, extension)`
  //
  // - __rules:__ The rules that should be used.
  // - __extension:__ The rest that you want to extend. (Special handling for attributes!)
  ruleValidator.extend = function(rules, extension) {
    var extObj = __.extend(__.clone(ValidationRules.prototype), extension);

    for (var r in rules) {
      var rule = rules[r];

      if (rule.type === 'object' && rule.properties) {
        extObj[r] = rule;
      } else {
        extObj[r] = {
          type: 'object',
          properties: rule
        };
      }

      extObj[r].ruleName = r;
      extObj[r].validate = function(data, callback) {
        extObj.validate(this.ruleName, data, callback);
      };
    }

    return extObj;

  };

}());