TwiceJS

Manage duplicates, count item occurences, dedupe an Array, in an easy way.

Getting started

Installation

To install TwiceJS, you just have to download TwiceJS.min.js in the dist folder and add a script into your HTML page :

<scriptsrc="path/to/TwiceJS.min.js"></script>

Or, if you prefer, you can use TwiceJS via NPM (or Yarn) :

# Use with npm
$ npm install --save @betaweb/twicejs
# Use with yarn
$ yarn add @betaweb/twicejs

Basic usage

There are several ways uo use TwiceJS, as you can see in the examples below.

constiterable=[{id: 1},{id: 1},{id: 2},{id: 1},{id: 3},{id: 3}]/* .: Instanciate via TwiceJS class :. */letset=newTwiceJS()set.append(iterable)// OR/* .: With Array prototype property `dedupe` :. */arr.dedupe()// it instanciates twiceJs under the hood, and exposes the instance in `twiceJs` propertyletset=arr.twiceJs

The main TwiceJS purpuse is to dedupe a collection, and especially an objects collection. You can get the deduped collection with the .entries getter.

// dedupe entriesconsole.log(set.entries)// > [{"id":1},{"id":2},{"id":3}]

You can also dedupe a collection, and get the count of occurrences for each entry with the .withCount getter.

// dedupe entries with occurences countconsole.log(set.withCount)// > [{"id":1,"_count":3},{"id":2,"_count":1},{"id":3,"_count":2}]

The key _count can be set by modifying the count_key option in TwiceJS's options object passed in parameter on instanciation.

Now, let see how handle the created collection with TwiceJS. There are three methods availables with TwiceJS : append, replace and remove.

// Removes all occurrences of `{id: 1}` on the collectionset.remove({id: 1})console.log(set.withCount)// > [{"id":2,"_count":1},{"id":3,"_count":2}]// Appends an entryset.append({id: 2})console.log(set.withCount)// > [{"id":3,"_count":2},{"id":2,"_count":2}]// Replaces all occurrences of `{id: 2}` by `{id: 7}`set.replace({id: 2},{id: 7})console.log(set.withCount)// > [{"id":3,"_count":2},{"id":7,"_count":2}]

Methods & events

Methods

TwiceJS.append(item: Array|Object[]|any): TwiceJS

Appends an item or a list of items on current collection.

constdataset=newTwiceJSconstitem={id: 4}dataset.append(item)// > [{id: 4}]// ORconstitems=[{id: 4},{id: 4},{id: 3}]dataset.append(items)// > [{id: 4}, {id: 4}, {id: 3}]

TwiceJS.replace(oldItem: any, newItem: any): TwiceJS

Replace an item on current collection.

constdata=[{id: 4},{id: 4}]constdataset=(newTwiceJS).append(data)constoldItem={id: 4}constnewItem={id: 5}dataset.replace(oldItem,newItem)// > [{id: 5}, {id: 5}]

TwiceJS.remove(item: Array|Object[]|any): TwiceJS

Remove an item or a list of items on current collection.

constdata=[{id: 4},{id: 4},{id: 5}]constdataset=(newTwiceJS).append(data)constitem={id: 4}dataset.remove(item)// > [{id: 5}]

TwiceJS.isEmpty(): Boolean

Returns true if the collection is empty, false otherwise.

constdata=[{id: 4},{id: 4}]constdataset=(newTwiceJS).append(data)constitem={id: 4}dataset.remove(item)dataset.isEmpty()// true

TwiceJS.clear(): TwiceJS

Clear the collection

constdata=[{id: 4},{id: 4},{id: 5}]constdataset=(newTwiceJS).append(data)dataset.clear()dataset.isEmpty()// true

TwiceJS.has(item: Array|Object[]|any): Boolean

Returns true if the collection contains the searched entry, false otherwise.

constdata=[{id: 4},{id: 4},{id: 5}]constdataset=(newTwiceJS).append(data)dataset.has({id: 4})// truedataset.has({id: 7})// false

TwiceJS.occurrence(item: Array|Object[]|any): Number

Get an entry occurrences count.

constdata=[{id: 4},{id: 4},{id: 5}]constdataset=(newTwiceJS).append(data)dataset.occurrence({id: 4})// 2dataset.occurrence({id: 7})// 0

TwiceJS.encode(item: Array|Object[]|any): String

Encode an entry according the defined key_encoder option.

constdataset=newTwiceJS({key_encoder: TwiceJS.ENCODERS.BASE_64})dataset.encode({id: 4})// eyJpZCI6NH0=

TwiceJS.decode(item: String): any

Decode an entry according the defined key_encoder option.

constdataset=newTwiceJS({key_encoder: TwiceJS.ENCODERS.BASE_64})constbase64_str=dataset.encode({id: 4})// eyJpZCI6NH0=dataset.decode(base64_str)// {id: 4}

Todo

• Add keyify option choice : JSON or base64.
• Add .increment(<item>) (alias of .append(<items>)) and .decrement(<item>) (alias of .delete(<item>)) methods which adds or removes only one occurrency of an entry on the collection, and increment or decrement his count.
• Rewrite TwiceJS class with TypeScript.
• Add unit tests.