# Dice Mist

Dice Mist is a wrapper for the [Evaporate library](https://github.com/TTLabs/EvaporateJS) providing web worker support.

When uploading multiple large files, it is possible for the upload process to lag the main JS thread, by delegating this work to a web worker you can keep your UI snappy.

## Installation

`npm i dice-mist`

## Usage

```javascript
import Mist from 'dice-mist';

const config = {
    // evaporate config
    worker: true // boolean to use worker or not
};

const files = [
    // array of Javascript Files
    // you MUST add an ID to each file, so that it can be track from the worker
    // E.g: files.forEach(file => {file.id = generateId()});
];

Mist(config, files)
    .progress((progress, id) => { /* File upload % progress - number between 0 & 1 */})
    .success((id, data, awsObjectKey) => { /* fileGuid, fileData, s3 key/path */})
    .error((reason, id) => { /* error reason, errored file */})
    .start((cancel, id) => { /* function to cancel individual file upload, file id */});
```

### Web Worker Crypto Functions

For ease of instantiation the web work implementation does not accept MD5 or SHA256 functions from the config.
These are set to [js-spark-md5](https://github.com/satazor/js-spark-md5) and [js-sha256](https://github.com/emn178/js-sha256).

## How It Works

![Sequence Diagram](https://raw.githubusercontent.com/DiceTechnology/dice-mist/master/docs/sequence.png "Upload Sequence Diagram")