backbone.validator

Validation plugin for Backbone allowing for setting of default values

npm install backbone.validator
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Backbone.Validator

Build Status

browser support

Versions

  • 1.1.5 - Added emptyOk to allow fields that would normally require more complex checking (i.e. a regex) to accept empty strings.
  • 1.1.0 - breaking changes General code clean up, allow for use via commonJS, requireJS, no module system, working with Backbone 1.0+, renamed methods and variables to camel case for JS consistancy.
  • 0.92.1 - Added is_instance pre-defined validator
  • 0.92.0 - Cleaned up the code a little, removed console.log statements, and changed to_equal to use _.isEqual for better comparison. Added comments for annotated source code, and started porting in tests from our internal codebase. Matching latest Backbone version tested against.
  • 0.4.3 - IE doesn't support Array.prototype.indexOf, switched to _.indexOf()
  • 0.4.1 - The default is now validated and rejected should it not match the validation rules. This should hopefully fix the call stack issues.
  • 0.4.0 - Fixed many recursion bugs, error fires correctly even when use_defaults is true. Passes 17 test cases so far.
  • 0.3.0 - Added format, removed is_url validator (not useful)
  • 0.2.5 - Pre-Defined validators
  • 0.2.0 - Initial release

Backbone Version

The version of this plugin you should use should match the version of Backbone that you're using, following Semver rules. Underscore will need to be the minimum version required for that version of Backbone.

Setup

Override the prototype.validate for your created model with the package.

var PrimateModel = Backbone.Model.extend({
  useDefaults: true,
  defaults: {
    type: "Gorilla",
    name: "Magilla"
  },
  validators: {
    type: {
      inList: ['Gorilla', 'Human', 'Monkey']
    },
    name: {
      isType: 'string'
    }
  }
});

PrimateModel.prototype.validate = require('backbone.validator');

If you want the system to substitute your defaults, set useDefaults on your model defintion to true, or pass in {useDefaults: true} to your options hash when setting or save-ing a model.

Remember: if you want to validate on set, you need to also include {validate: true}

Defining Validators

Validators are defined in the validator object as part of the model setup. If the value passed in doesn't meet your criteria for a valid value, return any value. If it does match your criteria, return nothing (undefined). You may attach multiple validators to each attribute -- they will be run in the order in which they are attached. If one of them fails, the entire validation will fail and error will be triggered.

var TestModel = Backbone.Model.extend({
  validators: {
    title: {
      fn: function(value){
        if(typeof(value) !== 'string'){
          return "The title has to be a valid string";
        }
      },
    },
    email: {
      regex: /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,6}$/i,
      emptyOk: true
    }
  }
});

var test_model = new TestModel();
test_model.set({title: "I am a title!"}, {validate: true});
test_model.get('title');
"I am a title!"
test_model.set({title: false}, {validate: true});
test_model.get('title');
"I am a title!"
test_model.set({email: 'todd@selfassembled.org'}, {validate: true});
test_model.get('email');
"todd@selfassembled.org"
test_model.set({email: ''}, {validate: true});
test_model.get('email');
""
test_model.set({email: 'hjkdhf'}, {validate: true});
test_model.get('email');
""

Catching errors

You can catch errors and do something with them by attaching a listener to the invalid event which is triggered when the validation fails.

TestModel.extend({
  initialize: function(){
    this.on('invalid', this.displayError);
  },
  displayError: function(errors){
    errors.forEach(function(error){
      console.log(errors.attr, errors.error);
    });
  }
});

var test_model = new TestModel();
test_model.set({title: "I am a title!"});
test_model.get('title');
"I am a title!"
test_model.set({title: false});
"The title has to be a valid string"
test_model.get('title');
"I am a title!"

Defaults

You can have the validation framework substitute a reasonable default for an invalid option. This is useful when bootstrapping the model from an untrusted source.

TestModel.extend({
  useDefaults: true,
  defaults: {
    title: "BAD TITLE"
  }
});

var test_model = new TestModel();
test_model.set({title: "I am a title!"});
test_model.get('title');
"I am a title!"
test_model.set({title: false});
"The title has to be a valid string"
test_model.get('title');
"BAD TITLE"

Empty fields with complex validation

If you have some complex set of validation rules that would normally not permit empty values, you can set emptyOk on the field. This will allow you to set the field to an empty string and still have it pass validation rules. This will bypass ALL validators for a given field, so use this with care!

Built-in tests

inList(value, list, attribute) → {string}

Tests if a value is a member of a given array

Parameters:
Name Type Description
value mixed

value to test

list array

the list of acceptable values

attribute string

the name of the model attribute

Source:
Returns:

error message, if any

Type
string

isKey(value, obj, attribute) → {string}

Tests to see if the value is the key on an object

Parameters:
Name Type Description
value string

the value to test

obj object

the object to test for keys

attribute string

the name of the model attribute

Source:
Returns:

error message, if any

Type
string

maxLength(value, length, attribute) → {string}

Tests to see if the value is under a max length

Parameters:
Name Type Description
value mixed

the value to test: string or array

length number

the maximum length for value

attribute string

the name of the model attribute

Source:
Returns:

error message, if any

Type
string

maxValue(value, limit, attribute) → {string}

Test a number fo make sure it's lower than a specified value

Parameters:
Name Type Description
value number

the number to test

limit number

the maximum value for this number

attribute string

the name of the model attribute

Source:
Returns:

error message, if any

Type
string

minLength(value, length, attribute) → {string}

Test to see if the value is over a min length

Parameters:
Name Type Description
value mixed

the value to test: string or array

length number

the minumum value for length

attribute string

the name of the model attribute

Source:
Returns:

error message, if any

Type
string

minValue(value, limit, attribute) → {string}

Tests a number to make sure it's at least a specified value or higher

Parameters:
Name Type Description
value number

the number to test

limit number

the minimum value

attribute string

the name of the model attribute

Source:
Returns:

error message, if any

Type
string

toEqual(value, example, attribute) → {string}

Test to see if two values are shallow equal

Parameters:
Name Type Description
value mixed

the value to test

example mixed

the desired value

attribute string

the name of the model attribute

Source:
Returns:

error message, if any

Type
string

Validate(attributes, options) → {array}

A drop-in replacement for the validate method on a Backbone model.

Usage:

var MyModel = Backbone.Model.extend({});
MyModel.prototype.validate = require('backbone.validate');
Parameters:
Name Type Description
attributes object

the attributes being set

options object

the options hash

Source:
Returns:

array of error objects, if any.

Type
array

generated with docme

Inspiration

The inspiration for this comes directly (along with the format function) from Thomas Pedersen's Backbone.Validation. There are a lot of similarities in structure, but different logic on how to perform the validations.

Backbone.Validator is copyright (c) 2012-2014 Todd Kennedy

License

Copyright (C) 2012-2014 Todd Kennedy

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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