Key Points

References

Key Concepts

Polyfills - added function for front-end clients

https://en.wikipedia.org/wiki/Polyfill_(programming)

In web development, a polyfill is code that implements a feature on web browsers that do not support the feature. Most often, it refers to a JavaScript library that implements an HTML5 web standard, either an established standard (supported by some browsers) on older browsers, or a proposed standard (not supported by any browsers) on existing browsers. Formally, "a polyfill is a shim for a browser API".^[1]

Polyfills allow web developers to use an API regardless of whether or not it is supported by a browser, and usually with minimal overhead. Typically they first check if a browser supports an API, and use it if available, otherwise using their own implementation.^[1][2] Polyfills themselves use other, more supported features, and thus different polyfills may be needed for different browsers. The term is also used as a verb: polyfilling is providing a polyfill for a feature.

• 1 Definition
• 2 Examples
  • 2.1 HTML5 Shiv
  • 2.2 -prefix-free
  • 2.3 Selectivizr
  • 2.4 Flexie
  • 2.5 CSS3 PIE
  • 2.6 JSON 2
  • 2.7 es5-shim
  • 2.8 FlashCanvas
  • 2.9 MediaElement.js
  • 2.10 BrowserID
  • 2.11 Webshims Lib

Shim

Formally, "a shim is a library that brings a new API to an older environment, using only the means of that environment

difference between polyfill and shim

What makes a polyfill different from the techniques we have already, like a shim, is this: if you removed the polyfill script, your code would continue to work, without any changes required in spite of the polyfill being removed.

Potential Value Opportunities

Potential Challenges

Candidate Solutions

Step-by-step guide for Example

sample code block

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