cheminfo
file-collection
Library to manage large amount of files coming from different sources
Introduction
This library allows to manipulate a large amount of files coming from local or remote sources.
This library allows to have the same code in the browser and in nodejs.
This package allows to create a file-collection than can further be saved as a ium file (zip file containing all the data
and an index.json file).
The structure of the zip file is at follow:
- index.json
- data/
- all the files
Installation
npm i file-collection
Basic usage
Append a browser filelist
import { FileCollection } from 'file-collection';
const fileList; // a fileList resulting from a drag / drop in the browser
const fileCollection = new FileCollection();
await fileCollection.appendFileList(fileList);
// get a zip file that can be reload later
const iumFile = fileCollection.toIum();
// list the content of the fileCollection
for (const file of fileCollection) {
console.log(file.name);
console.log(await file.text());
}Reload a 'ium' file
import { fromIum } from 'file-collection';
const fileCollection = await fromIum(iumFile);
for (const file of fileCollection) {
console.log(file.name);
console.log(await file.text());
}Using in a react component
A webSource is a URL to data like for example https://image-js.github.io/image-dataset-demo/index.json:
<MyComponent webSource onchange={(fileCollection) => {}}></MyComponent>Inside the component we should:
const fileCollection = new FileCollection();
if (webSource) fileCollection.appendWebSource(webSource);If we drag / drop some files we should:
fileCollection.appendFileList(fileList);If we drag / drop a 'ium' file we should replace the full fileCollection
const fileCollection = FileCollection.fromIum(iumArrayBuffer);
const state = fileCollection.get('state');If we want to save as a ium file:
fileCollection.set('state', myCurrentState);
const toSave = fileCollection.toIum();When fileCollection changes we can always retrieve the various files using:
const files = [...fileCollection]; // fileCollection is iterable on its files propertyReferencing files in the fileCollection
Internals - sources versus files
In an instance of FileCollection we have 2 properties:
- sources: an array containing the different data sources
- files: an array containing all the files contained in the different sources
Some source may contain many files. This is the case of the .iumfiles as well as for the .zip file.