Syntax Guide

Rules in indicative are defined using a string based expression to keep your code concise and clean. This guide gives you an in-depth overview of same.

Defining rules

const rules = {
  email: 'required|email|unique:users',
  password: 'required|min:6|max:30'
}
  1. Multiple rules are seperated using a Unix style pipe (|) operator and executed in sequence as they are defined.

  2. Some rules like unique, min or max accepts additional arguments and these arguments are passed after a colon : sign.

  3. For multiple arguments, you can seperate them with a comma.

A more complex rule defination will look as following.

const rules = {
  age: 'required|integer|range:16,65'
}

As you can see the range rule accepts 2 arguments and they are seperated by a comma.

Limitations

Since the validation rules are defined using a string based expression, it has certain limitations. You cannot use reserved keywords like : or a |, within arguments.

The following rule defination will fail to parse.

Fails
const rules = {
  standupHours: 'hours:hh:mm:ss'
}
Instead use
const { rule } = require('indicative')

const rules = {
  standupHours: [
    rule('required'),
    rule('hours', 'hh:mm:ss')
  ]
}

When defining advanced rules, it is feasible to use Arrays with the combination of rule method. The output of rule method is not processed any further and hence advanced configuration is allowed.

Nested data

A real world application does deal with nested data and running async validations inside a loop is never fun. Indicative makes it so simple to define rules on nested data sets.

const rules = {
  'user.username': 'required'
}

In the above rule, we are asking indicative to make sure the username is required inside the user object.

const data = {
  user: {
    username: 'unicorn'
  }
}
Indicative uses dot notation to target nested properties inside objects and arrays, which again keeps your code concise and easy to understand.

Targeting arrays

Just like Objects, you can also target indexes inside Arrays as follows.

const rules = {
  'users.0.username': 'required'
}

Here we are instructing indicative to validate the username property inside the users array, but only for 0 index.

Unknown indexes

Quite often you won’t know, how many items does an array contains, making it impossible to hardcode the indexes. This is where the * keyword comes in handy.

const rules = {
  'users.*.username': 'required'
}

The above rule, will validate all the username properties for all the objects inside the users array.

All together

Below is an example, showing the usage of a complex schema object.

const { rule } = require('indicative')

const rules = {
  'teams.*.name': 'required|alpha',
  'teams.*.url': 'required|alpha',
  'teams.*.standupTime': [
	 rule('required'),
     rule('hours', 'hh:mm')
   ]
}

Valid data set for above schema.

const data = {
  teams: [
	{
      name: 'paraffin',
      url: 'http://paraffin.yourcompany.com',
      standupTime: '10:20'
    },
	{
      username: 'draculas',
      url: 'http://draculas.yourcompany.com',
      standupTime: '10:40'
    }
  ]
}