validations

A validation library for JavaScript objects modeled loosely on ActiveRecord validations.

npm install validations
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validations-js

validations-js is a validation library for JavaScript objects modeled loosely on ActiveRecord validations. Currently supports options to validate requiredness, length, numericality, and format.

Requirements

Usage

You can install using npm:

npm install validations

Or download the validations.js file from github.

To use the validations library in Node.js require validations.js and call the validations function, passing it the object to be validated and a validation configuration, like so:

var validations = require('validations');
var errors = validations.validate(my_object, my_validation_config);

If using in the browser include underscore.js, inflection.js, validations.js and, if necessary, json2.js in your page instead of using require();

The various configuration options and the api for the errors object that is returned are discussed below.

Validation configuration

To specify the rules for the properties of an object, set the properties property of the validation configuration with a hash that contains the configuration for each property. For example, validating that an object has a required property can be done like so:

var errors = validations.validate(my_object, {
  properties: {
    my_prop: {
      required: true
    }
  }
});

To validate the length of property use the length option:

var errors = validations.validate(my_object, {
  properties: {
    my_prop_a: {
      length: {
        is: 1
      }
    },
    my_prop_b: {
      length: {
        is: 2
      }
    },
    my_prop_b: {
      length: {
        min: 1
      }
    }
  }
});

You can specify multiple options on a single property:

var errors = validations.validate(my_object, {
  properties: {
    my_prop_a: {
      required: true,
      length: {
        min: 1,
        max: 10
      }
    }
  }
});

Note: if a property is not required and it's blank (undefined or null), any other validation options defined for that property will not be applied.

These are all the validation options:

  • required
  • length
    • is
    • min
    • max
  • numericality
    • onlyInteger
    • greaterThan
    • greaterThanOrEqualTo
    • equalTo
    • lessThan
    • lessThanOrEqualTo
    • odd
    • even
  • format
    • pattern

Message configuration

validations-js comes packaged with a default set of error messages for each of the validation options:

{
  required: "{{name}} is required.",
  length: {
    is: "{{name}} must be exactly {{compare_to}} characters.",
    min: "{{name}} must be at least {{compare_to}} characters.",
    max: "{{name}} must not exceed {{compare_to}} characters."
  },
  numericality: {
    onlyInteger: "{{name}} must be an integer.",
    greaterThan: "{{name}} must be greater than {{compare_to}}",
    greaterThanOrEqualTo: "{{name}} must be greater than or equal to {{compare_to}}.",
    equalTo: "{{name}} must be equal to {{compare_to}}.",
    lessThan: "{{name}} must be less than {{compare_to}}.",
    lessThanOrEqualTo: "{{name}} must be less than or equal to {{compare_to}}.",
    odd: "{{name}} must be an odd number.",
    even: "{{name}} must be an even number."
  },
  format: {
    pattern: "{{name}} is not formatted correctly."
  }
}

{{name}} gets replaced with the name of the property in error, and {{compare_to}} gets replaced with the value that the object property was compared to, if relevant.

Any of these messages can be overridden by specifying a message option on the property configuration like so:

var errors = validations.validate(my_object, {
  properties: {
    my_prop: {
      required: true,
      message: "Where the hell is {{name}}?"
    }
  }
});

If you would like to override the message for a particular option for all properties in a configuration, you can pass a defaultMessages configuration like so:

var errors = validations.validate(my_object, {
  defaultMessages: {
    length: {
      is: "{{name}} must be {{compare_to}} characters in length, no more, no less."
    }
  },
  properties: {
    my_prop_a: {
      length: {
        is: 1
      }
    },
    my_prop_b: {
      length: {
        is: 2
      }
    }
  }
});

Errors object

The errors object returned by the validate function acts like the ActiveRecord Validations errors objects.

Here are the methods available:

  • count() - returns the total number of errors found. alias for size().

  • each(callback) - iterates through all the properties for which an error was found, passing errors and name of property to callback. e.g.:

    errors_result.each(function(errors, name) {
      util.puts("Errors on " + name + ":" + errors.join(" "));
    })
    
    errors is an normally an array of error messages. When using recursion, errors may be a child errors object on which all of these methods can be called.

  • isEmpty() - return true if there no errors.

  • messages() - returns all error messages in an array.

  • isInvalid(name) - returns true if an error was found with name.

  • length() - returns the total number of errors found. alias for size().

  • on(name) - returns all of the error messages for name as an array.

  • size() - returns the total number of errors found.

Recursion

validations-js can validate recursively. A property of an object can be an object that has its own configuration. Use the object option to specify a sub-configuration for an object property. For example, let's say you had an object representing a place, with a location property that is itself an object with a lat and lon property. You might validate it like so:

var errors = validations.validate(place, {
  properties: {
    name: {
      required: true,
      length: {min: 1, max: 80}
    },
    location: {
      object: {
        properties: {
          lat: {
            required: true,
            numericality: {greaterThanOrEqualTo: -90, lessThanOrEqualTo: 90}
          },
          lon: {
            required: true,
            numericality: {greaterThanOrEqualTo: -180, lessThanOrEqualTo: 180}
          }
        }
      }
    }
  }
})

The errors object returned by validate is also recursive. You would detect and display an error with the lat property like so:

if (!isBlank(errors)
    && errors.isInvalid("location")
    && errors.on("location").isInvalid("lat"))
  util.puts("Problem with lat: " + errors.on("location").on("lat").join(" "));

License

Copyright (c) 2010 Daniel Kim

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.

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