range-parsest

range-parsest

Range header field parser.

Installation

You can install range-parsest through NPM:

npm i range-parser

Methods

import { parse } from "range-parsest";

parse(size, header, options)

Parse the given header string where size is the size of the selected representation that is to be partitioned into subranges. A ParseResult will be returned.

Example ParseResult:

// A file of size 255 and a header requesting the first 100 bytes.
const result = parse(255, "bytes=0-100");
// Result is
({
  type: "bytes",
  ranges: [{ start: 0, end: 100 }],
  rangeCount: 1,
});

You can use a destructuring assignment to get these values quickly. For example:

// parse header from request
const { type, ranges } = parse(size, req.headers.range);

// the type of the subranges
if (type === "bytes") {
  for (const { start, end } of ranges) {
    // do something with start and end
  }
}

parseCompat

This function only exists for easy switching to range-parsest, please use the normal parse() method instead.

This function is fully compatible with the original range-parser's parseRange. You use the exact same API, but instead of importing it as

var parseRange = require("range-parser");

you import it as

import { parseCompat as parseRange } from "range-parsest";

ParseOptions

These properties are accepted in the options parameter of the parse function:

combine

Specifies if overlapping & adjacent subranges should be combined, defaults to false. When true, ranges will be combined and returned as if they were specified that way in the header.

parseRange(100, "bytes=50-55,0-10,5-10,56-60", { combine: true });
// Results in
({
  type: "bytes",
  ranges: [
    { start: 50, end: 55 },
    { start: 0, end: 10 },
    { start: 50, end: 60 },
  ],
  rangeCount: 3,
});

License

MIT