Common visualization UI fragments

This library contains a number of user interface fragments to be used in visualization based on Data-Driven Documents.

Installation

Install the fragments using npm install --save @gros/visualization-ui, then use them in your visualization sources with

import {Locale, Navbar, Navigation, Spinner} from '@gros/visualization-ui';

This requires that your visualization is built via Webpack or some other dependency bundler that supports rewriting ES2015 or later syntax.

Additionally, to enable spinner animations, include the SCSS sources into your bundler, or add the distributed CSS bundle to a Web page, for example using:

<link rel="stylesheet" href="dist/bundle.min.css">

Overview

The library provides four classes: Locale, Navbar, Navigation and Spinner. Objects must be instantiated with new and be provided an object as the first argument upon construction, which is provides configuration options for the fragment except for Locale where it provides localization specifications. All classes except for Locale have a configuration option container which defines a query selector for an element to insert the fragment into. In the Navbar class, the locale is passed separately upon construction.

Locale

Create a localization object to provide translated messages and attributes of a selected locale. For this purpose, the object must be instantiated with an object containing locale-specific attribute objects, with language codes as keys of the encompassing object. The attribute objects should have the same keys as each other, where "messages" plays a special role; it must be an object containing message keys and raw output or sprintf-compatible format strings. Also, "language" must provide a human-readable description of the locale in its own language.

The localization object can select a different language at any time, and can be queried for any attribute or message from the locale object. Additionally, it can generate a navigation list for selecting a different language (but it does not handle the selection change event itself and defaults to reloading the page with a different language as query parameter and the same anchor), and it can automatically replace elements with a data-message attribute in the document or a certain selection with their locale equivalent, using the element children as arguments. It can also replace attributes of elements when they are prefixed with data-message- and their attribute name is explicitly provided in the call to updateMessages.

Setup:

import * as d3 from 'd3';
import {Locale} from '@gros/visualization-ui';
import spec from './locales.json';
const locales = new Locale(spec, lang="en");
// Select locale from query string
locales.select(URLSearchParams(window.location.search).get("lang"));

console.log(locales.message("test"));
console.log(locales.message("format", [3, 'baz']));
// Replace all messages in document
locales.updateMessages();

// Replace all messages in a selection
locales.updateMessages(d3.select("#content"));

// Replace all messages in the document, including specific attributes
// (data-message-title and data-message-alt, in this example).
locales.updateMessages(d3.selection(), ["title", "alt"]);

// Generate navigation
locales.generateNavigation(d3.select("nav.languages"), "index.html", "lang");

Navigation bar

Create a horizontal navigation heading to provide a branding, menus and other accessibility links. The navigation bar structure is defined by nested objects and arrays, and optionally configuration and locale sources. The structure is optimized to define a navigation heading with items, links, icons, but also branding, burger, menu, dropdown and other sections.

Setup:

import {Locale, Navbar} from '@gros/visualization-ui';
const locales = new Locale();
const nav = new Navbar({
    "container": ".navbar", // Navbar container
    "base_url": "https://test.example", // Canonical URL of "base" website
    "languages": "#languages", // Selector of a menu in the structure
    "language_page": "index.html", // Canonical (may be relative to base_url)
    "language_query": "lang", // Query parameter to add for language switch
    "my_url": "https://example.com" // Referenced from a link with "config" key
}, locales);
nav.fill(structure);

See tests/navbar.json for an example structure. A JSON schema, provided at schema/navbar.json, describes what a valid structure looks like. The JSON schema is distributed with the package as a version-dependent schema, and the latest stable version is provided at the URL defined in the schema. Depending on your development environment, the schema at any of these locations may be used for validation and code completion.

Note that the navigation heading may be extended with more JavaScript, in order to improve its functionality on mobile/touch devices, for example how dropdowns appear and how the menus function when the device switches between screen sizes that affect the responsive design. We do not provide this functionality because different choices may be made here and may be equally valid.

Navigation

Create a horizontal navigation list to switch between views for different selections. The URL state is changed via the location hash, which is also checked on startup. Multiple navigation objects can exist concurrently if a unique prefix is given to each of them. By default, the first item in the navigation is selected, but this can be overridden by returning true in setCurrentItem, in which case nothing is selected if an unknown item is set in the location hash at start.

Setup and usage:

import {Navigation} from '@gros/visualization-ui';
const projectsList = ['BAR', 'BAZ', 'FOO'];
const projectsNavigation = new Navigation({
    container: '#navigation',
    prefix: 'project_',
    setCurrentItem: (project, hasProject, list) => {
        if (!hasProject) {
            console.log('An unknown project was selected: ' + project);
        }
        else {
            console.log('Selected project: ' + project);
        }
        return hasProject;
    },
    // Customize *link* properties of new items
    addElement: (element) => {
        element.text(d => `Project ${d}`);
    }
    // Access other *list item* selections via updateElement and removeElement
})
projectsNavigation.start(projectsList);

location.hash = '#project_FOO'; // Select the third project
location.hash = '#FOO'; // Not handled
location.hash = '#project_QUX'; // Unknown project selected

// Update navigation list
projectsNavigation.update(projectsList.concat('QUX', 'ZUR'));

The items in the list must be unique such that the appropriate element is selected. Using data objects as items in the provided navigation list is also supported as long as a key configuration is provided which acts as both the d3 data key function and the default method of displaying text and creating a comparable anchor in the navigation item link.

Spinner

Create a loading spinner which can be shown until the data is fully loaded.

Setup:

import * as d3 from 'd3';
import {Spinner} from '@gros/visualization-ui';
const loadingSpinner = new Spinner({
    container: '#container',
    id: 'loading-spinner',
    width: d3.select('#container').node().clientWidth,
    height: 100,
    startAngle: 220
});
loadingSpinner.update({width: 100}); // New configuration
loadingSpinner.start();

// ... Perform some loading, processing, etc.

loadingSpinner.stop();

Development

• The repository can be found on GitHub.
• GitHub Actions is used to run unit tests.
• SonarCloud performs quality gate scans and tracks them.
• Coveralls receives coverage reports and tracks them.
• You can perform local tests using npm test. This requires the source code repository for the test suite and installing the development dependencies, using npm install in the cloned repository directory.
• We publish releases to npm.
• Noteworthy changes to the library are added to the changelog.

License

The visualization fragments library is licensed under the Apache 2.0 License.