Rhaetia

Rhaetia is a lightweight static declarative router for React.

Installation

npm install rhaetia --save

Usage and Example

After installation, there are 6 main steps to using Rhaetia:

1. Import Rhaetia into your app at the top of each component you want to use it with:

import Rhaetia from 'rhaetia';

If you use Webpack, you could instead include Rhaetia in Webpack's ProvidePlugin(), and avoid having to write the above import statement over and over:

plugins: [
  new webpack.ProvidePlugin({
    Rhaetia: 'rhaetia',
  }),
],

2. In your top-level React Component, create a route_tree array that defines your app's routes.

const route_tree = [
  // These 2 routes are both wrapped in a "Front" React Component.
  [null, Front, [
    ['login', Login],
    ['register', Register],
  ]],
 
  // These 4 routes are wrapped in a "Main" React Component.
  // The 2nd route has 2 children; the first child is marked as default.
  // The 3rd and 4th routes include URL parameters.
  [null, Main, [
    ['', Home],
    ['settings', Settings, [
      ['profile', SettingsProfile, {is_default: true}],
      ['account', SettingsAccount],
    ]],
    ['post/:post_id', Post],
    [':username', Profile],
  ]],
 
  // This route has no children.
  ['terms', TermsConditions],
]

3. In your ReactDOM.render() function, wrap your top-level React Component with a Rhaetia.Router. Give the router your route_tree:

ReactDOM.render((
  <Rhaetia.Router routeTree={route_tree}>
    <App/>
  </Rhaetia.Router>
), document.getElementById('root'));

4. Return this.props.children in the render() of any component that is assigned children according to your route_tree (and also in your top-level React Component).

render() {
  return (this.props.children);
}

5. To pass additional props to a Component's Rhaetia-assigned children, use Rhaetia.renderChild:

// This Component will pass a `message` prop to any child that Rhaetia assigns to it
class Main extends React.Component {
  constructor(props) {
    super(props);
  }
  render() {
    return (
      <main>
        {Rhaetia.renderChild(this.props.children, {
          message: 'Hello World!',
        })}
      </main>
    );
  }
}
 
// This Component will receive a `message` prop from its parent
class Login extends React.Component {
  constructor(props) {
    super(props);
  }
  render() {
    return (
      <section>
        <h1>{this.props.message}</h1>
      </section>
    );
  }
}

6. To create intra-app links that don't refresh your entire app, use Rhaetia.A. With some extra setup, you could also use the shorthand A:

render() {
  return <A href='/photos'>{'Your Photos'}</A>
}

Documentation

<Rhaetia.Router/>

A Rhaetia router. Rhaetia.Router is a React Component, and should wrap your top-level Component (see step 3 in "Usage and Example" for an example). This Component can take three props: routeTree, page404, and fallbackURL.

Props

routeTree Array required

A route_tree array detailing every route in the app.

Every item in the array must be a route_branch array. These arrays must be ordered from most specific to most general, i.e. routes with URL parameters should appear after routes without them. For example:

const route_tree = [
  ['settings', Settings],
  ['post/new', NewPost],
 
  // This route_branch has a URL parameter as its second route_path piece.
  // Its partner above it has an identical first route_path piece, but a literal as its second
  // route_path piece.
  // This route must therefore appear after its partner, otherwise a URL like 'example.com/post/new'
  // would match this route instead of its partner.
  ['post/:post_id', Post],
 
  // This route_branch has a URL parameter as its first route_path piece, and is therefore the most
  // general.
  // It must be at the bottom, otherwise a URL like 'example.com/settings' would match this
  // route instead of the first one.
  [':username', Profile],
];

route_branch Array

A 2-4 element array detailing a single route in the app. The elements are, in order:

1. route_path String | null required

Used to match routes to the URL.

If the route_path contains / characters, it is split along those characters into route_path_piece's, and each route_path_piece compared individually.

• route_path_piece's beginning with an alphabetic character are treated as literal and exact matches.

• route_path_piece's beginning with : are treated as URL parameters, with the value of the URL parameter being stored under this.props.params with the piece as the key.

• route_path_piece's beginning with : and ending with ? are treated as optional URL parameters. They behave just like normal URL parameters, except when the URL doesn't contain the parameter; in this case, null is stored in this.props.params. Only the last route_path_piece in a route_path may be an optional URL parameter.

If the route_path is null, the route_children element of this route_branch must exist and will be examined for matching.

If the URL being matched against has query parameters, they will be stored in this.props.query as key-value pairs.

Consider the following examples:

// Matches 'example.com/login'
['login', Login],
 
// Matches 'example.com/user/1994', with the following stored in the matched element:
//   this.props.params.user_id = '1994'
['user/:user_id', User],
 
// Matches 'example.com/photo/4314955/edit?mode=guest', with the following stored in the matched element:
//   this.props.params.photo_id = '4314955'
//   this.props.query.mode      = 'guest'
['photo/:photo_id/edit', Photo],
 
// Matches 'example.com/admin/posts', with the following stored in the matched element:
//   this.props.params.post_id = null
// Also matches 'example.com/admin/posts/125', with the following stored in the matched element:
//   this.props.params.post_id = '125'
['admin/posts/:post_id?', Post],
 
// Behaves as follows:
//   'example.com/graphs'                renders  <Graph/>
//   'example.com/graphs/19'             renders  <Graph/>
//   'example.com/graphs/19/reviews'     renders  <Graph><Review/></Graph>
//   'example.com/graphs/19/reviews/75'  renders  <Graph><Review/></Graph>
// With `graph_id` and `review_id` stored in `this.props.params` of each rendered element.
['graphs/:graph_id?', Graph, [
  ['reviews/:review_id?', Review]
]],
 
// Defers matching to the route_branches in the `children` array.
// If one of those child routes is a match, it will be wrapped in MyElement.
[null, MyElement, children],

2. route_element React Component required

The React element that matches a certain route_path. Multiple route_branch arrays can have the same route_element value.

3. route_options Object optional

An object with optional properties of this route_branch. Valid properties are:

• is_default Boolean

  Default value is false. If true, then this route will behave as if its route_path were either its given value or ''. For example:

  ['settings', Settings, [
   
    // This first route will match both 'settings/profile' and 'settings'.
    ['profile', SettingsProfile, {is_default: true}],
   
    // This second route will match only 'settings/account'.
    ['account', SettingsAccount],
  ]],

  This is equivalent to just duplicating the route_branch and setting the duplicate's route_path to ''. This example below behaves exactly like the one above:

  ['settings', Settings, [
    ['', SettingsProfile],
    ['profile', SettingsProfile],
    ['account', SettingsAccount],
  ]],

• match_mode String

  Can be one of three values: 'exact', 'forgiving', or 'loose'. Default value is 'exact'.

  If 'exact', then this route will only match urls that follow the pattern of its route_path exactly and don't have any extra pieces. For example:

  // Both these routes will match `terms`, but not `terms/current`.
  ['terms', Terms],
  ['terms', Terms, {match_mode: 'exact'}],

  If 'forgiving', then this route will match urls that have extra pieces beyond the pattern of its route_path. It will replace the URL with one that matches the pattern of its route_path, i.e. it will truncate the URL and remove the extra pieces.

  // This route will match both `terms` and `terms/current`. In the latter case, it will replace
  // the URL with `terms`.
  ['terms', Terms, {match_mode: 'forgiving'}],

  If 'loose', then this route will also match urls that have extra pieces beyond the pattern of its route_path, but it will not truncate the URL.

  // This route will match both `terms` and `terms/current`. In the latter case, it will leave
  // the URL as `terms/current`.
  ['terms', Terms, {match_mode: 'loose'}],

  If a route_branch has children, then match_mode will be ignored.

• needs_children Boolean

  Default value is true. If false, then a route will be matched with whether or not its children are matched with. For example:

  // This first route tree will match both `graphs` and `graphs/bar`.
  ['graphs', Graphs, {needs_children: false}, [
    ['bar', GraphBar],
  ]],
   
  // This second route tree will match only `graphs/bar`.
  ['graphs', Graphs, [
    ['bar', GraphBar],
  ]],

  If a route_branch has no children, then needs_children will be ignored.

3. or 4. route_children Array | null required | optional

A route_tree array of child routes.

This is usually an optional parameter, but is required if route_path is null.

If the 3rd item in this route_branch is route_options, then route_children must be the 4th item. Otherwise, if no route_options is given, route_children must be the 3rd item.

page404 React Component optional

Any React Component that you want to be shown when Rhaetia does not find a matching route, or when show404() is called.

fallbackURL string optional

The fallback URL used by toFallback() (i.e. if toFallback() is used, fallbackURL must be defined). Useful for kicking an unauthenticated user out to a safe publicly-accessible URL.

---

push(), replace()

Aliases of history.push() and history.replace().

Use push() whenever you want the user to be able to use their browser's back button to return to the current route, e.g. when navigating to a new route upon a button click.

Use replace() whenever you don't want the user to be able to use their browser's back button to return to the current route, e.g. when kicking the user out of a route they aren't allowed to view and onto one they are allowed to.

These functions should be called on this.props.router, i.e.

this.props.router.push('/settings');

this.props.router.replace('/login');

---

setBlockDialog(getUserConfirmation)

Sets a function to be called whenever block() is called, and Rhaetia needs to check whether or not the user actually wants to leave a page (i.e. customizes the confirmation dialog).

Parameters

getUserConfirmation Function

A function that takes 2 arguments:

1. message - the message displayed in the confirmation dialog.

2. callback - call this function with true if the user indicates that they do wish to leave a page, and with false if otherwise.

As an example:

// This custom function is passed to `setBlockDialog` as a custom user confirmation function.
// If the response to an (imaginary) custom dialog is true, then it invokes the callback.
// It receives the `message` from `block()`, but ignores it.
openLeavePageDialog(message, callback) {
  if (responseToCustomDialog() === true) {
    callback();
  }
}
 
componentDidMount() {
  // If `setBlockDialog()` weren't called here, then the normal system dialog would appear when
  // `block()` is triggered.
  this.props.router.setBlockDialog(this.openLeavePageDialog.bind(this));
}

Return value

void

---

block()

Acts as a quasi-alias of history.block().

Use block() whenever you want to ask the user for confirmation as to whether or not they actually wish to leave a page when they click a button or link that will navigate them away.

Unlike history.block(), which returns a function you can call to cancel the block, this function returns void. To cancel the block, call unblock().

This function should be called on this.props.router, i.e.

this.props.router.block();

Parameters

Accepts the same parameters as history.block().

Return value

void

---

unblock()

Removes the block set by block(). If no block is set, nothing happens.

This function should be called on this.props.router, i.e.

this.props.router.unblock();

Parameters

None.

Return value

void

---

isBlocked()

Used to determine if a history block is currently set or not. This is useful for stopping functions that would otherwise execute some steps before making a history push or replace.

As an example:

// Consider a page with a form and a logout button. The logout button runs some code before sending
// the user back to the login page. If a user clicks the logout button on a page with a dirty form,
// one would want a confirmation message to appear before the logout button carries out any steps:
 
onLogout() {
  if (this.props.router.isBlocked()) {
    // Show confirmation message.
    // ...
    // If the user confirms, call `this.props.router.unblock()`,
    // then call `this.onLogout()` again.
  }
  else {
    // Do logout steps.
    // ...
    // Then push user to login page.
    this.props.router.replace('/login');
  }
}

Parameters

None.

Return value

boolean

---

show404()

Used to redirect to a 404 page without changing the URL. Whenever you wish to redirect to your 404 page, call:

this.props.router.show404();

Parameters

None.

Return value

void

---

toFallback()

Used to redirect to a fallback URL. Requires the fallbackURL prop to be defined on your Rhaetia.Router. Whenever you wish to redirect to your fallback URL, call:

this.props.router.toFallback();

Parameters

None.

Return value

void

---

Rhaetia.renderChild(child, props)

Used in React components that wrap other React components according to your route_tree.

To use, place one Rhaetia.renderChild() in your React component wherever you want its child to appear:

<main>
  {Rhaetia.renderChild(this.props.children, {
    message: 'Hello World!',
  })}
</main>

Parameters

child React component required

The child of this component. Usually passed in as this.props.children.

props Object optional

Any additional props that you wish to pass into the child of this component.

Return value

A React element representing the child of this component.

---

<A/>

Wrapper for an <a/> tag with a valid href attribute that uses push() (by default) to take the user to that href. Used for intra-app links in single page apps, where a regular <a/> tag is undesirable because it would cause the entire app to reload.

To use, place a <Rhaetia.A/> in your React component wherever you want an intra-app link, and give it an href attribute;

<Rhaetia.A href='/photos'>{'Your Photos'}</Rhaetia.A>

The shorthand <A/> also exists. To use, either adjust your import Rhaetia statement to include A:

import Rhaetia, { A } from 'Rhaetia';

Or, if you use Webpack, adjust your providePlugin() to include A:

plugins: [
  new webpack.ProvidePlugin({
    Rhaetia: 'rhaetia',
    A: ['rhaetia', 'A'],
  }),
],

This cleans up the above syntax a little:

<A href='/photos'>{'Your Photos'}</A>

Props

All props except for replace are passed down onto the rendered <a/> tag.

href String required

Used as the href attribute for the rendered <a/> element. Must be a relative URL; links with absolute URLs should directly use a regular <a/> element.

replace Boolean optional

If true (using ===), then this element will use replace() instead of push().