diff --git a/_posts/2018-09-15-isomorphic-apps.md b/_posts/2018-09-15-isomorphic-apps.md index 00a926c..abc0dcb 100644 --- a/_posts/2018-09-15-isomorphic-apps.md +++ b/_posts/2018-09-15-isomorphic-apps.md @@ -98,7 +98,7 @@ The first issue [I ran into](https://www.reddit.com/r/rust/comments/98lpun/unable_to_load_wasm_for_electron_application/) while attempting to bundle everything via `webpack` is a detail in the WASM spec: -> This function accepts a Response object, or a promise for one, and ... **[if it] does not match +> This function accepts a Response object, or a promise for one, and ... **[if > it] does not match > the `application/wasm` MIME type**, the returned promise will be rejected with a TypeError; > > [WebAssembly - Additional Web Embedding API](https://webassembly.org/docs/web/#additional-web-embedding-api) diff --git a/_posts/2020-07-24-isomorphic-apps copy.md b/_posts/2020-07-24-isomorphic-apps copy.md deleted file mode 100644 index ae6ebe8..0000000 --- a/_posts/2020-07-24-isomorphic-apps copy.md +++ /dev/null @@ -1,113 +0,0 @@ ---- -layout: post -title: "More Isomorphic Desktop Apps with Rust" -description: "They suck less now." -category: -tags: [rust, javascript, webassembly] ---- - -In honor of Webpack 5.0 being released and dramatically easing integration of WebAssembly, it's time -to revisit previous work done to use Electron as a backend for Rust GUI applications. - -Structure: - -- Why did I want to do this?: Potential to use Electron+WASM as Rust GUI; not truly native, but at - least experimenting with. -- Problems: Hard to use ecosystem, crates don't compile, MIME types, async loading -- What changed?: Webpack makes WASM loading asynchronous and easy in v5, Chrome now sets MIME type -- Demonstration and screenshots -- Closing thoughts: is it worth it? - ---- - -I wasn't expecting to write this, but it's 2020 and we could all use a win. When last I addressed -using WASM + Electron to write desktop applications in Rust, there were ultimately too many issues -to recommend this combination as feasible. Since then, there's been a lot of progress, and after -finding out [the biggest problem] has been addressed, I decided it was time to take another look at -where things stand. - -# Loading local WASM blobs - -Previously, the most significant issue was trying to actually load WASM blobs in Electron. This -problem was the result of a combination of factors: - -1. When using streaming WASM blobs - ([`WebAssembly.instantiateStreaming()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/instantiateStreaming)), - the blob must be returned with a `Content-Type` header of `application/wasm`. - - If the full WASM blob is loaded into memory first, the MIME type restriction does not apply. -2. When Chrome loads `file://` URLs, the `Content-Type` is unset. -3. Webpack prioritizes streaming WASM whenever available, and if it fails, has no graceful fallback. -4. When building Rust WASM binaries using `wasm-bindgen`, webpack is used to generate JS bindings - for the WASM blob. - -Putting all this together: - -- Electron loads the JS created by `wasm-bindgen`/webpack -- This JS file calls attempts to load the WASM blob, which just so happens to be located on disk -- Because the MIME type isn't set, loading fails - -This was a well-known issue; -[emscripten](https://github.com/emscripten-core/emscripten/blob/8914c5cd5e4ac35a806430e8c77c88cd8c65b234/src/preamble.js#L2295) -even included a graceful fallback for this scneario. It was possible to tweak the JS created by -`wasm-bindgen` to load WASM, but using `sed` to edit generated code will eventually lead to madness. - -I'm unable to figure out when exactly it changed, but requesting WASM blobs from `file://` URLs in -Chrome now sets the MIME type, and thus the blob is loaded correctly. Additionally, recent changes -to be released in Webpack 5 (specifically the `asyncWebAssembly` and `importAsync` -[experiments](https://webpack.js.org/configuration/experiments/)) enable loading WASM without a -separate launcher script. - -# The evolution of Rust - -Rust as a language has also made a great deal of progress since late 2018. Previously, some -widely-used crates (like `stdweb`) required a `nightly` Rust compiler to function. Now, nearly -everything compiles on `stable`. In addition, now that Rust supports `async/await`, it's much easier -to interact with Javascript. It's still necessary to use some crates like `wasm_bindgen` to assist -the interaction, but Rust can now make use of the same asynchronous paradigms that have proven to be -incredibly effective in Javascript. - -There's also been great progress on some crates to interact directly with the browser; `web-sys` and -`js-sys` enable easier interoperation with the browser, where previously users didn't have these -options available. - -The tooling and documentation has improved as well. `wasm-pack` has proven itself as a reliable "one -stop shop" tool for managing WASM projects. While using `wasm-bindgen` and `webpack` directly are -still necessary for building Electron apps (due to Webpack v5 not yet released), this should change -in the near future as well. - -# New examples - -(need to put some screenshots and link to the new examples here) - -# Outstanding issues - -While I haven't been directly involved in any of the progress made to improve Rust + WASM, it's -incredibly encouraging to see just how far everything has come. Seeing where the ecosystem stands -now, I think using Electron + Rust to build desktop applications is _feasible_. Not necessarily a -_good_ idea, not that it offers any specific benefit over using Javascript/Typescript, just that -it's now _feasible_. - -Looking forward, the things I think could be beneficial to address are: - -Put another way, these are the things that would be necessary for me to consider moving away from -Typescript: - -- Template/starter project examples - - Being able to `yarn create` a project and have it already set up with two-way JS to Rust - bindings would go a long way towards reducing the currently painful setup using either - `wasm-bindgen` or `wasm-pack`. -- Comparisons to Typescript and Neon - - Is there a development or performance benefit that comes from using Rust instead of Typescript? - Took some time to learn Typescript since the last post, and while it's possible that WASM might - execute faster, I'm not sure that Rust offers enough of a benefit to justify the significantly - more complex setup. It would be useful to port an existing (small) application to Rust so that - other developers can see a representative example of each and make a decision for themselves. - - Instead of embedding Rust in Electron by way of WASM, [Neon] can be used to develop extensions - that run natively and are "glued" to Electron via Javascript. Further investigation to clarify - the pros/cons of each approach would be helpful; are there situations in which WASM offers - benefits over Neon? Vice-versa? Both WASM and Neon already require more complex setups than - typical JS/TS setups. Using Rust stdlib instead of Node API's for system access is nice, being - forced into loose coupling is nice, but maybe the penalty associated with - bundling/distribution/etc. only makes sense for projects as large as Rust-analyzer, etc. -- Automatically generate bindings from TS definition files. Alternately, something like the JS - "@types" as a group to supervise maintenance of TS to Rust bindings?