reactjs

问题 I'm newbie in React but I'm developing an app which loads some data from the server when user open the app. App.js render this AllEvents.js component: const AllEvents = function ({ id, go, fetchedUser }) { const [popout, setPopout] = useState(<ScreenSpinner className="preloader" size="large" />) const [events, setEvents] = useState([]) const [searchQuery, setSearchQuery] = useState('') const [pageNumber, setPageNumber] = useState(1) useEvents(setEvents, setPopout) // get events on the main

问题 I want to do the equivalent of style="background-image: url(foo.jpg); background-image: -webkit-image-set(url(foo_1x.jpg) 1x, url(foo_2x.jpg) 2x)" in a React component. React requires me to provide a style object, not a string. But a JS object can't have the same property twice. How do I get two background-image properties? Also, the order is significant – the image-set needs to be last. It needs to be an inline style. (Because the URL is a dynamic, interpolated value retrieved from DB.) 回答1:

问题 webpack - v4+ material ui - v4.9.6 react - v16.12.0 In a normal way all classes should be as the last one from the first example. In some reason on production mode, many of the classes do not change. Any idea? Example 1: <div class="MuiDrawer-root MuiDrawer-docked jss408"></div> Example 2: <div class="MuiPaper-root jss469 MuiPaper-elevation1 MuiPaper-rounded"></div> 回答1: styles className is not designed as deterministic in prod mode. But the generated class names of the @material-ui/core

问题 I want to do the equivalent of style="background-image: url(foo.jpg); background-image: -webkit-image-set(url(foo_1x.jpg) 1x, url(foo_2x.jpg) 2x)" in a React component. React requires me to provide a style object, not a string. But a JS object can't have the same property twice. How do I get two background-image properties? Also, the order is significant – the image-set needs to be last. It needs to be an inline style. (Because the URL is a dynamic, interpolated value retrieved from DB.) 回答1:

问题 I want to do the equivalent of style="background-image: url(foo.jpg); background-image: -webkit-image-set(url(foo_1x.jpg) 1x, url(foo_2x.jpg) 2x)" in a React component. React requires me to provide a style object, not a string. But a JS object can't have the same property twice. How do I get two background-image properties? Also, the order is significant – the image-set needs to be last. It needs to be an inline style. (Because the URL is a dynamic, interpolated value retrieved from DB.) 回答1:

问题 I want to do the equivalent of style="background-image: url(foo.jpg); background-image: -webkit-image-set(url(foo_1x.jpg) 1x, url(foo_2x.jpg) 2x)" in a React component. React requires me to provide a style object, not a string. But a JS object can't have the same property twice. How do I get two background-image properties? Also, the order is significant – the image-set needs to be last. It needs to be an inline style. (Because the URL is a dynamic, interpolated value retrieved from DB.) 回答1:

问题 I'm in the process of setting up a Webpack configuration for a React project and I want to be able to import my components like this: import ComponentName from "components/ComponentName" instead of like this: import ComponentName from "../../components/ComponentName" (this all would be assuming that my components directory lives inside a src directory) Doing a little bit of research, so far I've found two different methods to achieve this using Webpack: Making Webpack resolve modules inside

问题 I'm in the process of setting up a Webpack configuration for a React project and I want to be able to import my components like this: import ComponentName from "components/ComponentName" instead of like this: import ComponentName from "../../components/ComponentName" (this all would be assuming that my components directory lives inside a src directory) Doing a little bit of research, so far I've found two different methods to achieve this using Webpack: Making Webpack resolve modules inside

问题 I'm in the process of setting up a Webpack configuration for a React project and I want to be able to import my components like this: import ComponentName from "components/ComponentName" instead of like this: import ComponentName from "../../components/ComponentName" (this all would be assuming that my components directory lives inside a src directory) Doing a little bit of research, so far I've found two different methods to achieve this using Webpack: Making Webpack resolve modules inside

问题 The react code below prints: before var rootElement after var rootElement render start outer render start outer render end inner render start inner render stop render end I was expecting: before var rootElement after var rootElement render start outer render start inner render start inner render stop outer render end render end How can this behaviour be explained ? How does this make sense ? Why is this happening ? Isn't it so that render should be recursively called for each children (in a