jScheme

A small and simple object schema library for the browser and node. It has no dependencies and comes in under 3KB compressed and gzipped.

Basic Usage

Here is a most simple example to validate an object with one property which has to be a string:

// Add a schema.
jScheme.add('person', {
    name: 'string'
}); 
 
// Validate a valid object against our first schema.
jScheme.validate('person', {
    name: 'Popeye'
});
 
// Let's see what happens if we check with an empty object.
jScheme.validate('person', {}); // false
jScheme.hasErrors(); // true
jScheme.getErrorMessages(); // ['person.name: required property missing']

Validators

You can add one or more validators to a property in a comma-separated validation string:

Like this: property: 'boolean, optional'

Predefined Validators

For your convenience there are a few predefined validators:

• string
• boolean
• number
• function
• array
• date
• regexp
• object
• falsy
• truthy
• not empty
  In fact the same as 'truthy' but it reads nicer, doesn't it?

Special Validators

• array of {{ validator }}
  E.g. 'array of string'
• optional
  By default all propoerties you specify are required. With this you can mark one as optional.
• required
  If you set the configuration propertiesRequired to false you can use this validator to mark a property as required.

Special Properties

• __validate
  Adds a validation to the parent property.
• __additionalProperty
  Here you can define a method that will be called for every unspecified additional property. The methods signature looks like this: function(key, value) { return false }.

A more complex example

// Let's try a more feisty schema
jScheme.add('person', {
    name: 'string'
    specialPowers:
        __additionalProperty: function(key, value) { return jScheme.validate('power', value) }
    relationshipStatus: 'relationship status'
    archenemies: 'array of villain, optional'
}); 
 
// Add another schema that can be nested in the first one
jScheme.add('villain', {
    name: 'string'
    dislikes: 'array of string'
});
 
jScheme.add('power', {
    hurts: 'boolean'
    hurtsMuch: 'boolean, optional'
});
 
// Add a custom validator for the relationship status
jScheme.add('relationship status', function(value) {
    return /it\'s (complicated|relaxed|depressing)/.test(value)
});
 
jScheme.validate('person', {
   name: 'Peter Pan'
   specialPowers:
     'nagging':  { hurts: true }
    relationshipStatus: "it's complicated"
    archenemies: [
        { name: 'John', dislikes: ['baby seals'] },
        { name: 'Mary', dislikes: ['fun', 'flirting'] }
    ]
});

Add your own Validators

You can add your own validators. They are treated just the same as the predefined ones. Also there is no difference if you add a schema or a validator in the way you define them in a validation string. The name of your validator can contain whitespaces so it is easier to read.

jScheme.add('your validator', function(value) {
    return true || false
});

Configuration

jScheme.configure({ 
  allowAdditionalProperties: true
  propertiesRequired: true
});

allowAdditionalProperties (default: true)
Objects are allowed to have other properties than the ones specified.

propertiesRequired (default: true)
The properties added in the schemas are required by default. If you want to make a property optional you can use the validator optional. If this configuration is set to false all properties will be optional by default and you can mark them as required with the validatior required.

License

jScheme is licensed under the MIT License.

In Short:

• You can use, copy and modify the software however you want.
• You can give the software away for free or sell it.
• The only restriction is that it be accompanied by the license agreement.