flux-constant

Unique constants for Flux apps.

Install

$ npm install flux-constant

Usage

Create constants one at a time.

var FluxConstant = require('flux-constant');

var IMPORTANT_THING = new FluxConstant('IMPORTANT_THING');

console.log(IMPORTANT_THING);
// { name: 'IMPORTANT_THING' }

console.log(IMPORTANT_THING.toString());
// IMPORTANT_THING

Or create a set of them.

var FluxConstant = require('flux-constant');

var Set = FluxConstant.set([
    'SEND_REQUEST',
    'RECEIVE_RESPONSE'
]);

console.log(Set);
/*
{
    SEND_REQUEST: { name: 'SEND_REQUEST' },
    RECEIVE_RESPONSE: { name: 'RECEIVE_RESPONSE' }
}
*/

console.log(Set.SEND_REQUEST instanceof FluxConstant);
// true

Why

With a Flux application you may have a set of constants such as:

var ContactConstants = {
    ActionTypes: {
        SEND_REQUEST: 'SEND_REQUEST',
        RECEIVE_RESPONSE: 'RECEIVE_RESPONSE'
    }
};

module.exports = ContactConstants;

You may have another set of constants that are really similar, but unreleated.

var SignupConstants = {
    ActionTypes: {
        SEND_REQUEST: 'SEND_REQUEST',
        RECEIVE_RESPONSE: 'RECEIVE_RESPONSE'
    }
};

module.exports = SignupConstants;

We just created action types that could collide though. Let's compare a bit:

var ContactConstants = require('./ContactConstants');
var SignupConstants = require('./SignupConstants');

ContactActionTypes = ContactConstants.ActionTypes;
SignupActionTypes = SignupConstants.ActionTypes;

console.log(ContactActionTypes.SEND_REQUEST === SignupActionTypes.SEND_REQUEST);
// true

That's not exactly what we wanted. This could bite us if we use these two sets of constants in the same process.

For example, if a Flux store was depending on these constants, it may take action on a payload it didn't intend to. This happens because we're just comparing strings.

One way to fix this is creating longer, more unique names:

var ContactConstants = {
    ActionTypes: {
        CONTACT_SEND_REQUEST: 'CONTACT_SEND_REQUEST',
        CONTACT_RECEIVE_RESPONSE: 'CONTACT_RECEIVE_RESPONSE'
    }
};

module.exports = ContactConstants;

This doesn't seem like a great way to move forward though. These names can get out of control as the application grows. Also, prefixing with CONTACT_ feels like duplicating unnecessary information.

So instead of passing around strings let's create objects that are unique (new). And best of all we can keep the simpler naming conventions.

var FluxConstant = require('flux-constant');

var ContactConstants = {
    ActionTypes: {
        SEND_REQUEST: new FluxConstant('SEND_REQUEST'),
        RECEIVE_RESPONSE: new FluxConstant('RECEIVE_RESPONSE')
    }
};

module.exports = ContactConstants;

We'll do the same thing as above but demonstrate the set shortcut.

var FluxConstant = require('flux-constant');

var SignupConstants = {
    ActionTypes: FluxConstant.set([
        'SEND_REQUEST',
        'RECEIVE_RESPONSE'
    ])
};

module.exports = SignupConstants;

And now they won't collide.

var ContactConstants = require('./ContactConstants');
var SignupConstants = require('./SignupConstants');

ContactActionTypes = ContactConstants.ActionTypes;
SignupActionTypes = SignupConstants.ActionTypes;

console.log(ContactActionTypes.SEND_REQUEST === SignupActionTypes.SEND_REQUEST);
// false

License

MIT

Don't forget

What you create with flux-constant is more important than flux-constant.