@frontity/components

API reference of `@frontity/components` package

This package is a collection of React components that have proven to be pretty useful for a Frontity project.

Table of Contents

• How to use

• Components

  • Link

    • Props

    • Usage

    • Auto Prefetch

    • Custom Link component

    • The link processor

  • Image

  • Script

    • Props

    • Usage

  • Iframe

    • Props

    • Usage

  • Switch

How to use

In order to use it, you just have to import the component you want to use in your theme from @frontity/components/ and place it wherever needed. For example, if we want to use the <Image />component:

import Image from "@frontity/components/image";

Components

Link

<Link /> is a React component that you can use in your Frontity project to define links that works with the internal routing system. Under the hood, this component uses the actions.router.set(link) method from @frontity/tiny-router and creates an <a/> tag.

This component requires having state.source.url properly configured. Have a look at the guide Setting the URL of the WordPress data source to learn more about this.

Props

Name	Type	Required	Default	Description
link	string	yes	---	The URL to link to.
target	string	no	_self	The target of the anchor. Possible values: _self or _blank.
onClick	function	no	undefined	The onClick handler. Can be used to pass an optional callback that will be invoked on click.
scroll	boolean	no	true	Whether the browser should scroll up to the top upon navigating to a new page.
prefetch	boolean	no	true	Whether Frontity should automatically prefetch this link or not. The prefetching mode is controlled through state.theme.autoPrefetch.
aria-current	string	no	undefined	Indicates the element that represents the current item within a container or set of related elements.

All "unknown" props passed to the Link are passed down to an anchor </a> tag.

Usage

import Link from "@frontity/components/link";

const MyComponent = () => (
  <Link link={linkUrl} onClick={(e) => console.log(e)}>
    This is a link
  </Link>
);

Auto Prefetch

This component can help implementing some auto prefetching strategies. The configuration for this is stored in the state so final users can modify it in their sites using their frontity.settings.js file.

Imagine that my-awesome-theme uses this component. Then, people can set the auto prefetch setting like this:

const settings = {
  // Other settings...
  packages: [
    {
      name: "my-awesome-theme",
      state: {
        theme: {
          autoPrefetch: "hover",
        },
      },
    },
    // Other packages...
  ],
};

The possible values for state.theme.autoPrefetch are:

Value	Description
no	No auto prefetch.
hover	Prefetches links on hover.
in-view	Prefetch links currently visible in the viewport.
all	Prefetches all internal links on the page.

Custom Link component

Using this <Link /> component is optional. You can create your own <Link /> component with your own logic.

Example of a custom <Link /> component implementation:

import React from "react";
import { connect } from "frontity";

const Link = ({
  state,
  actions,
  link,
  className,
  children,
  "aria-current": ariaCurrent,
}) => {
  const onClick = (event) => {
    // Do nothing if it's an external link
    if (link.startsWith("http")) return;

    event.preventDefault();
    // Set the router to the new url.
    actions.router.set(link);

    // Scroll the page to the top
    window.scrollTo(0, 0);
  };

  return (
    <a
      href={link}
      onClick={onClick}
      className={className}
      aria-current={ariaCurrent}
    >
      {children}
    </a>
  );
};

export default connect(Link);

The link processor

Frontity provides a link processor. The link processor works with the <html2react> component and can automatically detect <a> tags in the page/post content and intelligently convert them into <Link> components.

If the href attribute of the <a> tag is either:

• a relative link, or

• an absolute link on the same domain as the WordPress data source

then the processor will convert the the <a> tag into a <Link> component.

The <Link> component created by the processor will be modelled on the <a> tag and will have properties consistent with its attributes - e.g. the link property of the <Link> component will be the same as the href attribute of <a> tag being replaced. The processor will also convert absolute links on the same domain to be relative links.

If the href attribute of the <a> tag is an absolute link on a different domain from the WordPress data source, i.e. it is a link to an external site, then that tag will remain as is and will not be replaced or converted.

In order for this to work the link processor must be imported into the theme and included in the list of html2react processors. This would normally be done in the root level index.js of your theme. See the @frontity/html2react documentation and this page for more info.

import link from "@frontity/html2react/processors/link";

libraries: {
  html2react: {
    processors: [link],
  },

This link processor needs to be added to any theme that wants to uses this Client-side navigation for embedded links in the content.

Image

<Image /> is a React component that adds lazy-loading to the native WordPress images. Combined with @html2react/processors , you can add this functionality and optimize your images pretty easy.

Script

<Script /> is a React component that executes scripts tags found in content.

Props

Name	Type	Required	Description
src	string	no	URL to an external JavaScript file.
code	string	no	internal JavaScript code
id	string	no	ID for script element

Usage

External JavaScript file:

import Script from "@frontity/components/script";

const MyComponent = () => (
    <Script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js />
);

Internal JavaScript code

import Script from "@frontity/components/script";

const MyComponent = () => (
  <Script
    code={`
        const body = document.querySelector('body');

        // Triggers anytime anywhere in the body of the page is clicked
        body.addEventListener('click', e => {
            e.preventDefault();
            console.log('Button Works');
        });
    `}
  />
);

Iframe

<Iframe /> is a React component that implement lazy-load on iframe components. The approach taken in implementing this component is based off the edge cases in the table below.

Intersection Observer	Native Lazy	Height > 0	Output
true	true	true	Native Lazy Load
true	true	false	Intersection Observer
true	false	true	Intersection Observer
true	false	false	Intersection Observer
false	true	true	(not possible)
false	true	false	(not possible)
false	false	true	Normal Load (eager)
false	false	false	Normal Load (eager)

Native Lazy needs a height attribute. For that reason, we use the Intersection Observer when a height is not provided.

Props

Name	Type	Required	Description
title	string	yes	internal JavaScript code
src	string	no	URL to an external JavaScript file.
width	string	no	width of the iframe component
height	string	no	height of the iframe component
className	string	no	class name for the component
loading	string	no	"lazy" | "eager" | "auto" Default value: "lazy"
rootMargin	string	no	margin around root element

Usage

import Iframe from "@frontity/components/iframe";

const MyComponent = () => (
  <Iframe
    src="https://frontity.org"
    title="Frontity"
    height="500"
    width="500"
  />
);

Switch

The <Switch /> renders the first child component that returns true as the value of its when prop.

The last child component (which should not have a when prop) will be rendered if no other component matches the condition.

You can use it for routing to different components in your theme:

import Switch from "@frontity/components/switch";

const Theme = ({ state }) => {
  const data = state.source.get(state.router.link);

  return (
    <Switch>
      <Loading when={data.isFetching} />
      <Home when={data.isHome} />
      <Archive when={data.isArchive} />
      <Post when={data.isPostType} />
      <ErrorPage /> {/* rendered by default */}
    </Switch>
  );
};

But also inside any other component. For example, in a <Header> component that has a different menu for the home:

import Switch from "@frontity/components/switch";

const Header = ({ state }) => {
  const data = state.source.get(state.router.link);

  return (
    <Switch>
      <MenuHome when={data.isHome} />
      <Menu /> // rendered by default
    </Switch>
  );
};

This component is an alternative to applying plain JavaScript logic in React:

const Theme = ({ state }) => {
  const data = state.source.get(state.router.link);

  return (
    <>
      {(data.isFetching && <Loading />) ||
        (data.isHome && <Home />) ||
        (data.isArchive && <Archive />) ||
        (data.isPostType && <Post />) || <ErrorPage />}
    </>
  );
};