Vikasg7 / line-reader-browser

line-reader-browser allows browsers to read an input file line by line.

line-reader-browser

• Intro

  line-reader-browser allows browsers to read an input file line by line from source without reading whole file at once. I will recommend using nodejs and browserify to use this module.

• Install

  npm install git+https://github.com/Vikasg7/line-reader-browser.git

• Syntax

  import { LineReader } from "line-reader-browser"
  
  // file is javascript File Object returned from input element
  // chunkSize(optional) is number of bytes to be read at one time from file. defaults to 8 * 1024
  const file: File
  const chunSize: number
  const lr = new LineReader(file, chunkSize)
  
  // context is optional. It can be used to inside processLineFn   
  const context = {}
  lr.forEachLine(processLineFn, context)
    .then((context) => console.log("Done!", context))
  
  // context is same Object as passed while calling forEachLine
  function processLineFn(line: string, index: number, context: any) {
     console.log(index, line)
  }

• Usage (in TypeScript)

  import { LineReader } from "line-reader-browser"
  
  document.querySelector("input").onchange = () => {
     const input = document.querySelector("input")
     if (!input.files.length) return
     const lr = new LineReader(input.files[0], 4 * 1024)
     lr.forEachLine((line: string, i) => console.log(i, line)).then(() => console.log("Done!"))
  }

• Example

  I have added test.html which refers to the bundle.js in the dist/tests/ folder. Open test.html in the browser, choose the input file and see lines logging in the console.