numericconditionals

A small utility which can conditionally return data based on predefined conditions. This can be very useful to for example return different values based on a numeric value.

There are many possible uses - I for example use it for a Slack bot, which prefixes the current temperature with a fitting attribute (e. g. nice 20°C, cold -5°C etc.).

There are three types of objects, dependent on the each other:

• A Condition tests a specific case (e. g. is the value bigger than 10? Is it smaller than or equal to 9?)
• A Case tests multiple conditions and also holds data. You could for example say that a value should be bigger than 10 and less than or equal to 20, and store an array for when this case is true
• A Conditional compares a value against multiple cases. You can either return the data of the first case that fits or return the data of all cases that fit.

Installation

npm install numericconditionals

yarn add numericconditionals

Usage

const {
  Condition,
  Case,
  Conditional
} = require('numericconditionals');

Conditions

Creation

Build up your conditions:

const conditions1 = [
  new Condition('>', 0),
  new Condition('<=', 11)
];

const conditions2 = [
  new Condition('>', 10),
  new Condition('<=', 20)
];

The first one would match any value bigger than 0 (not 0 itself!), the second one would match any value less than or equal to 10.
The numbers are run through Number(), so you can use everything that fits in there.

Usage

Use conditions by calling isTrue() on a Condition:

const c1 = new Condition('>', 10);
c1.isTrue(12); // returns true
c1.isTrue(8); // returns false

Cases

Creation

Build up your cases from your conditions:

const cases = [
  new Case(
    conditions1,
    ['freezing', 'cold', 'terrible']
  ),
  new Case(
    conditions2,
    ['nice', 'warm', 'refreshing']
  )
];

Usage

You can test a Case by calling areConditionsTrue:

const c2 = new Case(
  [
    new Condition('>', 10),
    new Condition('<=', 20)
  ],
  ['data', 'which', 'will', 'be', 'returned']
);

c2.areConditionsTrue(15); // returns true
c2.areConditionsTrue(9); // returns false
c2.getValue(); // returns ['data', 'which', 'will', 'be', 'returned']

Conditionals

Creation

Build up your conditional:

const conditional = new Conditional(cases);

Usage

Now you can get values from your conditional. There are two possibilities:

conditional.getFittingCases(10.5); // returns ['freezing', 'cold', 'terrible']
conditional.getFittingCases(10.5, true); // returns [['freezing', 'cold', 'terrible'], ['nice', 'warm', 'refreshing']]
conditional.getFittingCases(15); //returns ['nice', 'warm', 'refreshing']

Now you could use these however you'd like - for example get a random value for your chat bot!