downlinkMax

About

downlinkMax is a 0.26KB Network Information API polyfill for navigator.connection.downlinkMax written in both CoffeeScript and JavaScript with AMD support.

Unlike most polyfills that try to add in missing functionally, this script is currently focused on standardizing the available information across specification versions of the Network Information API and returning the estimated maximum downlink speed for the device.

This information can then be used to make educated decisions about how to dynamically optimize the user experience. It could be something as simple as defaulting video playback to HD when the user has enough bandwidth, or removing costly elements from the page such as unnecessary images when the user's mobile browser is on 2G, to completely disabling site features because the experience would be unacceptable (such as video upload).

Examples

JavaScript

// get the maximum downlink speed
var speed = downlinkmax();

// check if it is enough for our amazing feature
if (speed < sufficient) {
  disableFeature();
}

CoffeeScript

# get the maximum downlink speed
speed = downlinkmax()

# check if it is enough for our amazing feature
disableFeature() if speed < sufficient

Should Do List?

• Try to estimate bandwidth by timing the download of a predefined image

Install Choices

• bower install downlinkmax
• download the zip

Tasks

All tasks can be run by simply running gulp or with the npm test command, or individually:

• gulp lint will lint source code for syntax errors and anti-patterns.
• gulp gpa will analyze source code against complexity thresholds.
• gulp test will run the jasmine unit tests against the source code.
• gulp test-coffee will run the jasmine unit tests against the CoffeeScript source code.
• gulp test-min will run the jasmine unit tests against the minified code.

License

(The MIT License)

Copyright (c) 2014 Daniel Lamb [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.