Open Source W3C Web Component

Storyboard

Multi-panel story with cool effects

by Read Write Tools
Abstract
The rwt-storyboard web component displays a sequence of panels that tell a story. Transitions from one panel to the next can slide-in or fade-in to dramatic effect. The content of each panel is provided by an HTML template, and the sequencing speed can be controlled by CSS variables.

Motivation

The rwt-storyboard web component is intended for use on web pages where the author wants to grab the reader's attention and funnel them towards a particular action.

The component has these features:

  • Each panel may contain any arbitrary content and styling.
  • Each panel may be transitioned to visibility using it's own effect.
  • The first panel can be shown with an initial delay before the sequencing begins.
  • The last panel can be shown with a final hold time before restarting the full sequence.
  • Sequencing occurs only when the component is fully visible within the browser's viewport. It is suspended when the component is hidden or only partially visible.
  • The user may suspend the auto-sequencing by clicking anywhere within the component's frame, and may resume the auto-sequencing by clicking the component a second time.
  • Round buttons along the bottom of the storyboard allow the user to override the auto-sequencing to display a particular panel.

Prerequisites

The rwt-storyboard web component works in any browser that supports modern W3C standards. Templates are written using BLUEPHRASE notation, which can be compiled into HTML using the free Read Write View desktop app. It has no other prerequisites. Distribution and installation are done with either NPM or via Github.

Installation using NPM

If you are familiar with Node.js and the package.json file, you'll be comfortable installing the component just using this command:

npm install rwt-storyboard

If you are a front-end Web developer with no prior experience with NPM, follow these general steps:

  • Install Node.js/NPM on your development computer.
  • Create a package.json file in the root of your web project using the command:
  • npm init
  • Download and install the web component using the command:
  • npm install rwt-storyboard

Important note: This web component uses Node.js and NPM and package.json as a convenient distribution and installation mechanism. The web component itself does not need them.

Installation using Github

If you are more comfortable using Github for installation, follow these steps:

  • Create a directory node_modules in the root of your web project.
  • Clone the rwt-storyboard web component into it using the command:
  • git clone https://github.com/readwritetools/rwt-storyboard.git

Using the web component

After installation, you need to add two things to your HTML page to make use of it.

  • Add a script tag to load the component's rwt-storyboard.js file:
  • <script src='/node_modules/rwt-storyboard/rwt-storyboard.js' type=module></script>             
  • Add the component tag somewhere on the page with these two attributes:
    • Apply a sourceref attribute with a reference to an HTML file containing the panels. See details below.
    • Optional. For WAI-ARIA accessibility apply a role=contentinfo attribute.

Here's an example:

<rwt-storyboard sourceref='/five-panel-story.html' role=contentinfo></rwt-storyboard>

Panel template

The sourceref file should contain valid HTML consisting of two or more section elements. The contents of each section is treated as a panel.

Transition effects are declared by adding the two special attributes data-next and data-prev to each section. In this example (shown using BLUEPHRASE notation for clarity), each panel will transition to visibility using fade-in and transition to hidden using fade-out:

section *data-next='fade-in' *data-prev='fade-out' {
Ask a leading question
}
section *data-next='fade-in' *data-prev='fade-out' {
Pose a suggested answer
}
section *data-next='fade-in' *data-prev='fade-out' {
State the product's feature
}
section *data-next='fade-in' *data-prev='fade-out' {
Assert that user needs the product
}
section *data-next='fade-in' *data-prev='fade-out' {
Give user easy way to get it
}

The possible transition values are:

fade-in
from-left
from-right
from-top
from-bottom

fade-out
to-left
to-right
to-top
to-bottom

Customization

Dimensions

The width and height of the storyboard are set using the CSS variables --width and --height.

rwt-storyboard {
--height: 10rem;
--width: 40rem;
}

Color scheme

The default color palette for the storyboard uses a dark mode theme. You can use CSS to override the variables' defaults:

rwt-storyboard {
--color: var(--white);
--background: var(--black);
--button-color: var(--pure-white);
}

Important: the content of each panel can be customized with any CSS you want, but that CSS must be included in the sourceref template file together with the panel's HTML declarations. CSS that is outside the component is firewalled and will not pierce the document/component barrier.

Timing variables

The sequencing of panel transitions is controlled by CSS variables. Each variable may specify values in units of seconds (s) or milliseconds (ms).

  • --duration-in is the duration for a new panel to become fully visible.
  • --duration-out is the duration for the previous panel to become completely hidden.
  • --delay-in is the amount of time to wait before starting a panel's transition from hidden to visible.
  • --delay-out is the amount of time to wait before starting a panel's transition from visible to hidden.
  • --initial-delay is the initial amount of time to show the first panel, before beginning the transition to the second panel.
  • --sequence-time is the total time from one panel to the next. Normally this should be equal to --duration-in + --duration-out + --delay-in + --delay-out.
  • --hold-time is the final amount of time to show the last panel, before restarting the full sequence.
rwt-storyboard {
--duration-in: 2s;
--duration-out: 2s;
--delay-in: 0s;
--delay-out: 0s;
--initial-delay: 6s;
--sequence-time: 4s;
--hold-time: 6s;
}

Life-cycle events

The component issues life-cycle events.

component-loaded
Sent when the component is fully loaded and ready to be used. As a convenience you can use the waitOnLoading() method which returns a promise that resolves when the component-loaded event is received. Call this asynchronously with await.

License

The rwt-storyboard web component is licensed under the MIT License.

MIT License

Copyright © 2020 Read Write Tools.

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.

Availability

Source code github
Package installation NPM
Documentation Read Write Hub

Storyboard — Multi-panel story with cool effects

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