![]() ![]() React 14 and React 16), as placing the JSX namespace in the global scope can cause issues. React and Preact) or different versions of a specific library (e.g. This can be helpful when mixing and matching different libraries (e.g. For example, if your JSX factory is React.createElement, TypeScript will try to first resolve React.JSX, and then resolve JSX from within the current scope. In TypeScript 2.8, the compiler will try to look up the JSX namespace based on the location of your JSX factory. dom( "h ", null) JSX is resolved via the JSX FactoryĬurrently, when TypeScript uses JSX, it looks up a global JSX namespace to look up certain types (e.g. Var renderer_1 = require( "./renderer ") If you’ve used the same functionality in Babel, this should look slightly familiar. Luckily, TypeScript 2.8 now allows you to set your JSX factory on a file-by-file basis by adding an // comment at the top of your file. ![]() However, if you needed to mix any of these libraries in the same application, you’d have been out of luck using JSX for both. Previously, TypeScript only allowed users to control the emit for JSX at a global level using the jsxFactory option (as well as the deprecated reactNamespace option). However, if you’re using libraries that have a React-like factory API, such as Preact, Stencil, Inferno, Cycle, and others, you might want to tweak that emit slightly. Typically, users of JSX expect to have their JSX tags rewritten to React.createElement. For an example of repositories taking advantage of this flag, check out urql from Formidable Labs, or take a look at our Babel starter repo. One use-case for this is when using alternate compilers for TypeScript such as Babel 7. d.ts files that can be used for library consumers. Under this mode no JavaScript files nor sourcemap files will be generated just. Thanks to a pull request from Manoj Patel, TypeScript now features an -emitDeclarationOnly flag which can be used for cases when you have an alternative build step for emitting JavaScript files, but need to emit declaration files separately. ![]() boolean type Bar = Exclude Declaration-only emit We also have some minor breaking changes that you should keep in mind if upgrading.īut otherwise, let’s look at what new features come with TypeScript 2.8! Conditional typesĬonditional types are a new construct in TypeScript that allow us to choose types based on other types.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |