@ -778,6 +800,8 @@ Embeds a web page as a slide background that covers 100% of the reveal.js width
</section>
```
Iframes are lazy-loaded when they become visible. If you'd like to preload iframes aehad of time, you can append a `data-preload` attribute to the slide `<section>`. You can also enable preloading globally for all iframes using the `preloadIframes` configuration option.
#### Background Transitions
Backgrounds transition using a fade animation by default. This can be changed to a linear sliding transition by passing `backgroundTransition: 'slide'` to the `Reveal.initialize()` call. Alternatively you can set `data-background-transition` on any section with a background to override that specific transition.
@ -1065,18 +1089,38 @@ The framework has a built-in postMessage API that can be used when communicating
When reveal.js runs inside of an iframe it can optionally bubble all of its events to the parent. Bubbled events are stringified JSON with three fields: namespace, eventName and state. Here's how you subscribe to them from the parent window:
This cross-window messaging can be toggled on or off using configuration flags.
#### postMessage Callbacks
When you call any method via the postMessage API, reveal.js will dispatch a message with the return value. This is done so that you can call a getter method and see what the result is. Check out this example:
This cross-window messaging can be toggled on or off using configuration flags. These are the default values.
```javascript
Reveal.initialize({
@ -1208,7 +1252,7 @@ The speaker notes window will also show:
- Current wall-clock time
- (Optionally) a pacing timer which indicates whether the current pace of the presentation is on track for the right timing (shown in green), and if not, whether the presenter should speed up (shown in red) or has the luxury of slowing down (blue).
The pacing timer can be enabled by configuring by the `defaultTiming` parameter in the `Reveal` configuration block, which specifies the number of seconds per slide. 120 can be a reasonable rule of thumb. Timings can also be given per slide `<section>` by setting the `data-timing` attribute. Both values are in numbers of seconds.
The pacing timer can be enabled by configuring the `defaultTiming` parameter in the `Reveal` configuration block, which specifies the number of seconds per slide. 120 can be a reasonable rule of thumb. Alternatively, you can enable the timer by setting `totalTime`, which sets the total length of your presentation (also in seconds). If both values are specified, `totalTime` wins and `defaultTiming` is ignored. Regardless of the baseline timing method, timings can also be given per slide `<section>` by setting the `data-timing` attribute (again, in seconds).
## Server Side Speaker Notes
@ -1237,7 +1281,7 @@ Then:
Plugins should register themselves with reveal.js by calling `Reveal.registerPlugin( 'myPluginID', MyPlugin )`. Registered plugin instances can optionally expose an "init" function that reveal.js will call to initialize them.
When reveal.js is booted up via `Reveal.initialize()`, it will go through all registered plugins and invoke their "init" methods. If the "init" method returns a Promise, reveal.js will wait for that promise to be fullfilled before finshing the startup sequence and firing the [ready](#ready-event) event. Here's an example of a plugin that does some asynchronous work before reveal.js can proceed:
When reveal.js is booted up via `Reveal.initialize()`, it will go through all registered plugins and invoke their "init" methods. If the "init" method returns a Promise, reveal.js will wait for that promise to be fulfilled before finshing the startup sequence and firing the [ready](#ready-event) event. Here's an example of a plugin that does some asynchronous work before reveal.js can proceed:
If the init method does _not_ return a Promise, the plugin is considered ready right away and will not hold up the reveal.js startup sequence.
Note that reveal.js will *not* wait for init Promise fullfillment if the plugin is loaded as an [async dependency](#dependencies). If the plugin's init method does _not_ return a Promise, the plugin is considered ready right away and will not hold up the reveal.js startup sequence.
var slidesUnderMinimum = timings.filter( function(x) { return (x <minTimePerSlide)}).length
if ( slidesUnderMinimum ) {
message = "The pacing time for " + slidesUnderMinimum + " slide(s) is under the configured minimum of " + minTimePerSlide + " seconds. Check the data-timing attribute on individual slides, or consider increasing the totalTime or minimumTimePerSlide configuration options (or removing some slides).";
Hakim El Hattab
4 years ago
committed by
GitHub