How Does React Tell a Class from a Function?

Post by finchisko » Mon, Dec 03, 2018, 5:09 PM UTC

malvosenior wrote: post #109

finchisko wrote: post #39

Earlier quoted context omitted.

> I really don't get how JS on the client and the server is any real advantage from my own experience, using single language has huge influence on overall code quality. Makes you understand it much better, comparing to situation you must switch between multiple languages. As you gain more experience in it, the less obvious bugs you'll make (just by knowing what's good and what's wrong). The worst js code I see, is co…

Can I ask if you've ever programmed in another language on the backend? I've done plenty of JS and many backend languages and I'd never consider using JS on the backend. > from my own experience, using single language has huge influence on overall code quality. From my experience, JS code is really poor quality and overly complex (looking at your build chain) even when written by an expert.

Post by sametmax » Mon, Dec 03, 2018, 5:26 PM UTC

ergothus wrote: post #107

sametmax wrote: post #96

Earlier quoted context omitted.

I have this doubt as well. Hooks will allow people to use "class like" features and behavior, but with none of the conventions forced by syntax, plus some pitfalls. To me it seems a good way to ensure most devs (espacially unexperienced casual ones, which are legions in JS by nature of the market) will dump their logic wherever it works with as little structure as it allows. It's a technical debt catalyser, and will…

> will dump their logic wherever it works with as little structure as it allows. It's a technical debt catalyser, and will make sure nobody feels at home in someone else's code. The community will pay the price in a year. I don't want to downplay your concerns, but I will say that this is already a problem. Part of the goal with hooks (and I can't say if it achieves that) is to encourage the separation of a lot of st…

Post by brlewis » Mon, Dec 03, 2018, 5:33 PM UTC

prossercj wrote: post #91

danabramov wrote: post #72

Earlier quoted context omitted.

>to me, separating out that function is a good thing To us, too, and that's exactly the point of Hooks. They let you extract logic into functions in a way that wasn't possible before. I suggest to read more than a single page -- in particular, extracting custom Hooks is largely the point of the proposal. https://reactjs.org/docs/hooks-custom.html I also wrote about this here: https://medium.com/@dan_abramov/making-se…

That post has changed my opinion about hooks. I find this gist especially compelling: https://gist.github.com/gaearon/cb5add26336003ed8c0004c4ba82... Without hooks, that example would require adding a method (or two) to the component class. With custom hooks, that code can go into a separate module. Component bloat has been a problem for us, and if hooks can enable components to focus solely on render logic, I'd say…

    class WidthStore {
        width: stream.Stream;
        constructor() {
            this.width = stream(window.innerWidth);
            window.addEventListener('resize', () => {
                this.width(window.innerWidth);
                m.redraw();
            });
        }
    }

    const widthStore: WidthStore = new WidthStore();

    class MyResponsiveComponent {
        view(vnode) {
            return 
Window width is {widthStore.width()}
;
        }
    }

Post by lioeters » Mon, Dec 03, 2018, 5:50 PM UTC

sametmax wrote: post #96

quietbritishjim wrote: post #66

Earlier quoted context omitted.

I absolutely agree with you. This makes me very skeptical about the proposed feature in React, called "hooks", which is linked to in the article. It lets you add state to your functional components, and it looks like you end up bundling all your code into one function rather than having a separate constructor to initialise the state (to me, separating out that function is a good thing). I would be interested in the m…

I have this doubt as well. Hooks will allow people to use "class like" features and behavior, but with none of the conventions forced by syntax, plus some pitfalls. To me it seems a good way to ensure most devs (espacially unexperienced casual ones, which are legions in JS by nature of the market) will dump their logic wherever it works with as little structure as it allows. It's a technical debt catalyser, and will…

Post by pier25 » Mon, Dec 03, 2018, 6:05 PM UTC

IMTDb wrote: post #64

arry wrote: post #60

What's the rationale for allowing the components to be defined as functions in the first place? As far as I can see, it has a single thing going for it: saving a line of code, at the expense of jumping through the JavaScript hoops to implement the class/function distinction described in the post. Besides, when the function component evolves and acquires the need for state or other features, the saved line of code goe…

To me it's all about intent. By using a function instead of a class, you are basically saying "future reader, this component is nothing more than a simple mapping from those values to that DOM tree, don't try to look for internal states or any complex treatment here". Sure you could write a "normal React component without state" and do the same, but having those properties baked in the way you defined the component i…