Hacker News Reader

Comment by jjcm | Hacker News Reader

Presentation is amazing here.

That said, I recently wrote a webcomponent based router and I was surprised at how easy it was to get to a very usable point at such a minimal amount of code. All too often I get in the loop of just `npm i`'ing whatever it is I need, even if the functionality I really need is just a tiny subset of whatever huge library I'm importing.

Rodrigo's right that something like this helps you understand React and how to contribute to the codebase, but I think it goes further than that - it lets you understand that the library isn't magic. It gives you the confidence you need to think that maybe you don't need that full 560kb library.

View on HN

Redux is a very good example of this. If you watch the original talk or just understand primitives like Observables, you can realize that Redux almost isn't a library. It's basically a pattern. Where libraries are actually required is when you connect Redux to React, or need async actions. But even then it's not super hard to see how they work.

Yep. The Redux core `createStore` function can be distilled down to about 25 lines [0], and the rest of the core lib can be added in another 75-ish [1].

I've seen Redux described as "a pattern with really good documentation", and there's some truth to that. On the other hand, we've put a _lot_ of work into React-Redux in particular [2] to make sure it's optimized and works well with React.

As a side note, we have a new official Redux Toolkit package [3] that is our recommended approach for writing Redux logic. It includes utilities to simplify several common Redux use cases, including store setup, defining reducers, immutable update logic, and even creating entire "slices" of state at once.

[0] https://blog.isquaredsoftware.com/2017/05/idiomatic-redux-ta...

[1] https://gist.github.com/gaearon/ffd88b0e4f00b22c3159

[2] https://blog.isquaredsoftware.com/2018/11/react-redux-histor...

[3] https://redux-toolkit.js.org

> webcomponent based router

Routers can be (and should be, IMO) written to be independent of UI component libraries such as React and webcomponents. See an example here: https://github.com/Rajeev-K/mvc-router You can use it with React---and in some ways it works better than react-router.

Yeah I'm not a fan at all of react-router because it's too dependent on React. For redirecting, for example, they recommend you render a <Redirect> component. Which is just bananas to me.

The alternative would be to write a side effect inside your `render()` function, which is illegal -- it breaks the new Concurrent mode rendering, which can call render() speculatively.

I mean, I see why it's intuitively unappealing to you, but there are perfectly good reasons for the design.

There are "perfectly good reasons" in the sense that if you artificially limit yourself to using the React component tree to manage routes, yes it makes sense how they arrived at this solution. But after dealing with it for a while, it's just so obviously not the correct approach, and it's crazy to me that it's the defacto router. Cargo culting at its finest. The router could exist outside of or at a higher level than the component tree.

It's the defacto router because it has gone through many iterations, has lots of users, is easy to bring into a React app, and doesn't fight w/ React, it works with it. Plus there are a variety of approaches to declaring routes. [0]

I'm not sure I see how obvious it is that a <Redirect/> is wrong. But that's fine, I take your point that it's not particularly intuitive.

I'm of the opinion that routing, in general, is a function of application state - and I like to manage my application state with Redux - so I will often also mix in connected-react-router [1]. This lets you do navigation w/ an imperative API [2].

[0] https://github.com/ReactTraining/react-router/tree/master/pa...

[1] https://github.com/supasate/connected-react-router

[2] https://github.com/supasate/connected-react-router/blob/mast...

The alternative would be to write a side effect inside your `render()` function, which is illegal

That's one alternative. Another is not to try implementing behaviour that has nothing to do with rendering using a rendering library in the first place.

A horrible amount of accidental complexity has been created in the React ecosystem when people have tried to use it like a full framework. If all you have is a hammer, maybe it's time to consider using other tools as well.

It's not really bananas when you actually start to think of everything 'as components', and consider that 'render' can neatly, declaratively describe behaviour, not just the DOM.

could you recommend any articles/tutorials that describe this approach some more?

This Ryan Florence talk is a great talk that touches on this topic, especially in some of the more creative examples: https://www.youtube.com/watch?v=kp-NOggyz54

thanks!

'render' should render, because that's what the function name says. If you're using it for behavior then you're not using it for the intended purpose.

Now that hooks exist, this should definitely be the case. Before, HoCs / components with render prop functions were actually useful for doing some additional not-directly-render related work.

You can now use hooks for some things you might previously want a component for, e.g. useFetch instead of <Fetch />, but don't agree "this should definitely be the case". Dogma is never good.

Strongly disagree, and 'because the function is called that' is a very poor reason.

You're not using React to its full potential if you think like this.

That _is_ how I think about components, but it's still bananas. Render does not neatly describe this behavior because it necessitates setting unnecessary state. That's gross.

Usually when I need to trigger a redirect, I'm in some business-level function. So to redirect this way, I would need to set some state in my store, re-render, then hit the conditional, which would redirect, probably unset that state, and then probably trigger some additional business logic.

When really all I want to do is in the business function, directly trigger the redirect and maybe some other logic without any indirection. redux-react-router exists, but it's API is still obtuse compared to something like redux-first-router.

> When really all I want to do is in the business function, directly trigger the redirect and maybe some other logic without any indirection.

Heh, didn't see this comment before I left a novel up the tree. Seems we have similar ideas about state management.

I think the default RR API is straight React, and that is by design.

Since you are talking about using Redux, you most definitely can dispatch push actions with libs like connected-react-router or just use the history API directly (for things like replacing state instead of pushing). Most of the redirects I write are inside business logic and I don't like mixing <Redirect /> in there, too.

Then you can use `useHistory` (or `withRouter` if you're not hooks-ready).

I somewhat agree that the <Redirect /> component is not actually that useful, it's only useful in very simple cases like "based on one route plus conditional redirect to another", e.g.:

    <Route path="/">
      {usersPreviousShoppingGender === "women" ? (
        <Redirect to="/women" />
      ) : (
        ...
      )}
      ...
    </Route>
    <Route path="/women">

It’s bananas to you that a library with the word react in the name would be dependent on react? It’s an add on you would literally never use unless you are building a react app

My favorite routers to use with React at the moment are redux-first-router (define a route map, and an object in your Redux store gets automatically two-way synced with browser location state; your 'routing' is actually just a switch statement over the current location state), and Next.js (make some component files under pages/ and they get automatically rendered as routes; wrap a filename in brackets and it's used as a query param value wildcard). Both have advantages and disadvantages but are very low-mental-overhead in practice.

Disagree there's anything really low-mental-overhead about bringing redux into your project.

Can second redux-first-router being fantastic.

Web components are not a UI library though. They are the native component model for the web.

HTML custom elements (basis for web components) are intended for things that should be added to DOM. Using it for any other purpose is probably a misuse.

In my personal case I'm using it so the DOM is more literal as to what's happening on the page. I'm of the naive opinion that you should be able to read the DOM and have a general sense of what the site looks like. Since I'm making a single-page site that loads everything at once, I have a webcomponent based router that declaratively states what route will be active given the URL. For example:

    𝚖𝚢-𝚛𝚘𝚞𝚝𝚎𝚛
      𝚖𝚢-𝚛𝚘𝚞𝚝𝚎(𝚙𝚊𝚝𝚝𝚎𝚛𝚗="/𝚑𝚘𝚖𝚎")
        // 𝚜𝚘𝚖𝚎 𝚑𝚘𝚖𝚎 𝚙𝚊𝚐𝚎
      𝚖𝚢-𝚛𝚘𝚞𝚝𝚎(𝚙𝚊𝚝𝚝𝚎𝚛𝚗="/𝚗𝚎𝚠𝚜")
        // 𝚜𝚘𝚖𝚎 𝚗𝚎𝚠𝚜 𝚙𝚊𝚐𝚎

not sure what happened, but your code example is almost all tofu (unicode [X]) to me. looks like it's using characters like "mathematical monospace lowercase letter 'm'" etc

edit: unidecoded:

  my-router
        my-route(pattern="/home")
        // some home page
        my-route(pattern="/news")
        // some news page

Especially when you consider a non-trivial amount of the react-dom codebase is actually Synthetic Event handling (smoothing out differences in browser implementations). If you're using "the platform" and understand native events, that's a huge saving for you and your users.

> you don't need that full 560kb library

In fact, most web applications only need this 200-line library: https://github.com/wisercoder/uibuilder

React started out as a simple library, but it is getting more and more complicated (see concurrent mode). 90% of applications don't benefit from React's complexity. This tiny lib has the same templating technology as React, but none of the complexity.

Concurrent mode seems to come out of actual research regarding managing what is rendered when and what people like / don't like and expect to be rendered and when ... and providing more control over that.

I guess that's complicated but I can see even basic apps benefiting from it.

Reply on news.ycombinator.com