express-response-range

Middleware for handling content-range with querystring fallback.

Example

 var express = require('express')
 var responseRange = require('express-response-range')


 var data = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

 var options = {};
 
 var app = new express();
 app.use(responseRange(options)); // creates req.range and expose res.sendRange(data[,count]) method
    
 app.get('/', function(req, res, next) {
  var slicedData = data.slice(req.range.offset, req.range.offset + req.range.limit);
  return res.sendRange(slicedData,slicedData.length); // send data and sets 206 status if request Range header is set 
 });

 app.listen(process.env.PORT)

API

constructor([options])

Returns middleware handling range header. For every call the req.range is created from request headers/querystring.

• options
  • unit - name of unit (default items)
  • queryFallback - enable query fallback for requests without range (default true)
  • alwaysSendRange - send range response (plain payload) for non-ranged request (default false)
  • defaultLimit - default limit for response (default 10)
  • maxLimit - max limit for response (default none)
  • zeroBasePagination - page parameter starts from 0 (default false)

res.sendRange(data[,count])

Sends response (with res.send) and creates content-range header (or creates payload {items:[],count:X} for queryFallback)

• data - data to send to response
• count - number of items in whole collection (sent with range items 0-10/X)

Query Fallback

When client doesn't support ranges, querystring parameters could be used (?offset&limit&page).

• page - can be used to compute offset (offset = (page-1) * limit)

Note - when using zeroBasedPagination the page parameter could be from zero (offset = page * limit)