# `srcdoc` polyfill [](https://travis-ci.org/jugglinmike/srcdoc-polyfill)
HTML5 defines a new attribute for iFrames named `srcdoc`. This attribute allows
developers to specify an iFrame's content in-line with the iFrame itself. For
instance:
This feature only began to see adoption in major browsers in early 2013.
Fortunately, most older browsers support similar functionality through
script-targeted URLs, i.e.
(Because of limitations on URL length, the actual mechanism that the polyfill
implements not quite this direct.)
For more on `srcdoc`, see [the WhatWG specification](http://www.whatwg.org/specs/web-apps/current-work/multipage/the-iframe-element.html#attr-iframe-srcdoc) and [this post on
Bocoup.com](http://weblog.bocoup.com/third-party-javascript-development-future/).
## Usage
By including the script at the bottom of the document ``, any available
iFrames which declare a `srcdoc` attribute attribute) will receive this
"shimmed" behavior. (In browsers that already implement this functionality, no
change will take place.)
**Note on [the HTML5 `sandbox`
attribute](https://html.spec.whatwg.org/multipage/embedded-content.html#attr-iframe-sandbox):**
Because the shim operates using a script-targeted URL in legacy environments,
some configurations of the `sandbox` attribute may interfere with its behavior.
This issue will only surface in environments that implement `sandbox` but that
do *not* implement `srcdoc`. Because of this, this polyfill's default behavior
is to issue a warning for potentially-hazardous configurations but to proceed
optimistically. The API supports an `force` option that enables modification of
this behavior.
## Executing
This script may be consumed as a AMD module, a CommonJS module, or standalone
via direct inclusion with a `