Overview

The ZeroClipboard JavaScript library provides an easy way to copy text to the clipboard using an invisible Adobe Flash movie. The "Zero" signifies that the library is invisible and the user interface is left entirely up to you.

Browsers won't let you access the clipboard directly. So this library puts a Flash object on the page to proxy the clipboard for you. The library will move and resize over all the clipped objects.

Installation

If you are installing for Node:

npm install zeroclipboard

If you are installing for the web, you can use Bower:

bower install zeroclipboard

Setup

To use the library, simply include the following JavaScript file in your page:

<script type="text/javascript" src="ZeroClipboard.js"></script>

You also need to have the "ZeroClipboard.swf" file available to the browser. If this file is located in the same directory as your web page, then it will work out of the box. However, if the SWF file is hosted elsewhere, you need to set the URL like this (place this code after the script tag):

ZeroClipboard.config( { moviePath: 'http://YOURSERVER/path/ZeroClipboard.swf' } );

Clients

Now you are ready to create one or more clients. A client is a single instance of the clipboard library on the page, linked to one or more DOM elements. Here is how to create a client instance:

var client = new ZeroClipboard();

You can also include an element or array of elements in the new client. **This example uses jQuery to find "copy buttons".

var client = new ZeroClipboard($(".copy-button"));

Next, you can set some configuration options.

Configuration Options

These are default values for the global configurations options. You should generally update these before you create your clients.

var _globalConfig = {
  // NOTE: For versions >= v1.3.x and < v2.x, you must use `swfPath` by setting `moviePath`:
  //   `ZeroClipboard.config({ moviePath: ZeroClipboard.config("swfPath") });`
  // URL to movie, relative to the page. Default value will be "ZeroClipboard.swf" under the
  // same path as the ZeroClipboard JS file.
  swfPath: "path/to/ZeroClipboard.swf",

  // SWF inbound scripting policy: page domains that the SWF should trust. (single string or array of strings)
  trustedDomains: [window.location.host],

  // Include a "nocache" query parameter on requests for the SWF
  cacheBust: true,

  // Forcibly set the hand cursor ("pointer") for all clipped elements
  forceHandCursor: false,

  // The z-index used by the Flash object. Max value (32-bit): 2147483647
  zIndex: 999999999,

  // Debug enabled: send `console` messages with deprecation warnings, etc.
  debug: true,

  // Sets the title of the `div` encapsulating the Flash object
  title: null,

  // Setting this to `false` would allow users to handle calling `ZeroClipboard.activate(...);`
  // themselves instead of relying on our per-element `mouseover` handler
  autoActivate: true,


  /** @deprecated */
  // The class used to indicate that a clipped element is being hovered over
  hoverClass: "zeroclipboard-is-hover",

  /** @deprecated */
  // The class used to indicate that a clipped element is active (is being clicked)
  activeClass: "zeroclipboard-is-active",

  /** @deprecated */
  // DEPRECATED!!! Use `trustedDomains` instead!
  // SWF inbound scripting policy: page origins that the SWF should trust. (single string or array of strings)
  trustedOrigins: null,

  /** @deprecated */
  // SWF outbound scripting policy. Possible values: "never", "sameDomain", "always"
  allowScriptAccess: null,

  /** @deprecated */
  // Include a "nocache" query parameter on requests for the SWF
  useNoCache: true,

  /** @deprecated */
  // URL to movie
  moviePath: "ZeroClipboard.swf"
};

You can override the defaults by making a call like ZeroClipboard.config({ moviePath: "new/path" }); before you create any clients.

You can also set the options when creating a new client by passing an optional "options" object, e.g.

var client = new ZeroClipboard($("#d_clip_button"), { moviePath: "new/path" });`

However, this per-client options overriding is deprecated as of v1.3.0 and will be removed in v2.0.0.

Whenever possible, we recommend that you change the defaults rather than changing options per client. This works out better in most situations as:

Some options apply outside of ZeroClipboard instances, e.g. debug currently affects some static methods.
If you have multiple clients clipped to a shared element, having per-client options can result in confusing effects when that shared element is being activated, e.g. differing values for zIndex, forceHandCursor, hoverClass, activeClass, etc.

The `trustedDomains` option: SWF inbound scripting access

This allows other SWF files and HTML pages from the allowed domains to access/call publicly exposed ActionScript code, e.g. functions shared via ExternalInterface.addCallback. In other words, it controls the SWF inbound scripting access.

If your ZeroClipboard SWF is served from a different origin/domain than your page, you need to tell the SWF that it's OK to trust your page. The default value of [window.location.host] is almost always what you will want unless you specifically want the SWF to communicate with pages from other domains (e.g. in iframes or child windows).

For more information about trusted domains, consult the official Flash documentation for flash.system.Security.allowDomain(...).

The `allowScriptAccess` option: SWF outbound scripting access

This allows the SWF file to access/call JavaScript/HTML functionality of HTML pages on allowed domains, e.g. invoking functions via ExternalInterface.call. In other words, it controls the SWF outbound scripting access.

For version 1.1.7 and below, the embed tag had the allowScriptAccess parameter hard-coded to always. This allowed the "ZeroClipboard.swf" file to be hosted on an external domain. However, to enhance security, versions after 1.1.7 have an option for allowScriptAccess with a default of "sameDomain", which only allows "ZeroClipboard.swf" to be served from the same domain as the hosting page.

If you hosted "ZeroClipboard.swf" on a different domain than the hosting page on version 1.1.7 or below, when you upgrade to a version above 1.1.7, you should either move "ZeroClipboard.swf" to the same domain as the hosting page or set the allowScriptAccess option to always.

As of version 1.3.0, it is no longer necessary to set the allowScriptAccess configuration option as its default value is now null but the appropriate value will be determined immediately before the Flash object is embedded on the page. The value is based on a relationship between the current domain (window.location.host) and the value of the trustedDomains configuration option.

TL;DR default values:

≥ v1.3.0: null (appropriate value determined on-the-fly during embedding)
> v1.1.7 < v1.3.0: "sameDomain"
≤ v1.1.7: "always"

For more information about allowScriptAccess, consult the official Flash documentation.

Cross-Protocol Limitations

ZeroClipboard was intentionally configured to not allow the SWF to be served from a secure domain (HTTPS) but scripted by an insecure domain (HTTP).

If you find yourself in this situation (as in Issue #170), please consider the following options:

Serve the SWF over HTTP instead of HTTPS. If the page's protocol can vary (e.g. authorized/unauthorized, staging/production, etc.), you should include add the SWF with a relative protocol (//s3.amazonaws.com/blah/ZeroClipboard.swf) instead of an absolute protocol (https://s3.amazonaws.com/blah/ZeroClipboard.swf).
Serve the page over HTTPS instead of HTTP. If the page's protocol can vary, see the note on the previous option (1).
Update ZeroClipboard's ActionScript codebase to call the allowInsecureDomain method, then recompile the SWF with your custom changes.

Text To Copy

Setting the clipboard text can be done in 4 ways:

Add a dataRequested event handler in which you call client.setText to set the appropriate text. This event is triggered every time ZeroClipboard tries to inject into the clipboard. Example:
```
client.on( 'dataRequested', function (client, args) {
   client.setText( "Copy me!" );
});
```
Set the text via data-clipboard-target attribute on the button. ZeroClipboard will look for the target element via ID and try and get the text value via .value or .textContent or .innerText.

<button id="my-button" data-clipboard-target="clipboard_text">Copy to Clipboard</button>

<input type="text" id="clipboard_text" value="Clipboard Text"/>
<textarea id="clipboard_textarea">Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</textarea>
<pre id="clipboard_pre">Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</pre>

Set the text via data-clipboard-text attribute on the button. Doing this will let ZeroClipboard take care of the rest.

<button id="my-button" data-clipboard-text="Copy me!">Copy to Clipboard</button>

Set the text via client.setText property. You can call this function at any time; when the page first loads, or later like in a dataRequested event handler. Example:

client.setText( "Copy me!" );

The important caveat of using client.setText is that the text it sets is transient and will only be used for a single copy operation. As such, we do not particularly recommend using client.setText other than inside of a dataRequested event handler; however, the API will not prevent you from using it in other ways.

Clipping

Clipping refers to the process of "linking" the Flash movie to a DOM element on the page. Since the Flash movie is completely transparent, the user sees nothing out of the ordinary.

The Flash movie receives the click event and copies the text to the clipboard. Also, mouse actions like hovering and mouse-down generate events that you can capture (see Event Handlers below).

To clip elements, you must pass an element, or array of elements to the clip function.

Here is how to clip your client library instance to a DOM element:

client.clip( document.getElementById('d_clip_button') );

You can pass in a reference to the actual DOM element object itself or an array of DOM objects. The rest all happens automatically -- the movie is created, all your options set, and it is floated above the element, awaiting clicks from the user.

Example Implementation

<button id="my-button" data-clipboard-text="Copy me!" title="Click to copy to clipboard.">Copy to Clipboard</button>

And the code:

var client = new ZeroClipboard( $("button#my-button") );

CSS Effects

Since the Flash movie is floating on top of your DOM element, it will receive all the mouse events before the browser has a chance to catch them. However, for convenience these events are passed through to your clipboard client which you can capture (see Event Handlers below). But in addition to this, the Flash movie can also activate CSS classes on your DOM element to simulate the ":hover" and ":active" pseudo-classes.

If this feature is enabled, the CSS classes "hover" and "active" are added / removed to your DOM element as the mouse hovers over and clicks the Flash movie. This essentially allows your button to behave normally, even though the floating Flash movie is receiving all the mouse events. Please note that the actual CSS pseudo-classes ":hover" and ":active" are not used -- these cannot be programmatically activated with current browser software. Instead, sub-classes named "zeroclipboard-is-hover" and "zeroclipboard-is-active" are used. Example CSS:

  #d_clip_button {
    width:150px;
    text-align:center;
    border:1px solid black;
    background-color:#ccc;
    margin:10px; padding:10px;
  }
  #d_clip_button.zeroclipboard-is-hover { background-color:#eee; }
  #d_clip_button.zeroclipboard-is-active { background-color:#aaa; }

These classes are for a DOM element with an ID: "d_clip_button". The "zeroclipboard-is-hover" and "zeroclipboard-is-active" sub-classes would automatically be activated as the user hovers over, and clicks down on the Flash movie, respectively. They behave exactly like CSS pseudo-classes of the same names.

Event Handlers

The clipboard library allows you set a number of different event handlers. These are all set by calling the on() method, as in this example:

client.on( 'load', my_load_handler );

The first argument is the name of the event, and the second is a reference to your function. The function may be passed by name (string) or an actual reference to the function object

Your custom function will be passed at least one argument -- a reference to the clipboard client object. However, certain events pass additional arguments, which are described in each section below. The following subsections describe all the available events you can hook.

Event handlers can be removed by calling the off() method, which has the same method signature as on():

client.off( 'load', my_load_handler );

load

The load event is fired when the Flash movie completes loading and is ready for action. Please note that you don't need to listen for this event to set options -- those are automatically passed to the movie if you call them before it loads. Example use:

client.on( 'load', function ( client, args ) {
  alert( "movie has loaded" );
});