You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session. You switched accounts on another tab or window. Reload to refresh your session. Dismiss alert
Fellow JavaScripters, it's time to admit it: we have a problem with promises. No, not with promises themselves. Promises, as defined by the A+ spec, are awesome. The big problem, which has revealed itself to me over the course of the past year, as I've watched numerous programmers struggle with the PouchDB API and other promise-heavy APIs, is this: Many of us are using promises without really unde
One of the trickiest aspects of PouchDB is that its API is asynchronous. I see no shortage of confused questions on Stack Overflow, Github, and IRC, and most often they stem from a misunderstanding of callbacks and promises. We can't really help it. PouchDB is an abstraction over IndexedDB, WebSQL, LevelDB (in Node), and CouchDB (via Ajax). All of those APIs are asynchronous; hence PouchDB must be
はじめに この記事は、 JavaScript/ES6 promisesについてを理解するために読んだ方がよいと思われる記事やスライド等を紹介しています。 PromisesやDeferredといった言葉を非同期処理の話などで聞いた事があるかもしれませんが、 現在Promisesは次のECMAScriptの言語仕様として策定が進められています。 ECMAScript Language Specification ECMA-262 6th Edition – DRAFT domenic/promises-unwrapping まだES6は策定段階ですが、既にPromisesについてはpolyfillとして利用できるライブラリ等もあり、また他のライブラリ内でもjQuery.Deferred()やAngularの$q等類似する実装が存在します。 そのため、Generators等に比べると今すぐ使える
I bet you think “callback hell” is about function nesting and levels of indentation. Not so much. I bet you’ve heard that Promises replace callbacks. Nope. We need some clarity on what async flow control is all about in JavaScript. We’ll explore the perils of “Inversion of Control”, and see just what hell that leads us to. Then we’ll talk about promises as “continuation events” for function calls
This blog post is outdated. Please read chapter “Promises for asynchronous programming” in “Exploring ES6”. This blog post is an introduction to asynchronous programming via promises in general and the ECMAScript 6 (ES6) promise API in particular. It is second in a series of two posts – part one explains foundations of asynchronous programming (which you may need to learn in order to fully underst
Taming the Asynchronous Beast with CSP Channels in JavaScript This is an entry in a series about rebuilding my custom blog with react, CSP, and other modern tech. Read more in the blog rebuild series. Every piece of software deals with complex control flow mechanisms like callbacks, promises, events, and streams. Some require simple asynchronous coordination, others processing of event or stream-b
何がしたいか ゲームループがループごとにイベントを複数生成するのだが、それを時系列に沿って順番に捌きたい でもオブザーバでグローバルなイベント投げまくるとすぐクソコード化する どうにかしてピュアなモデルからビューとの待ち合わせ(オブザーバー含む)を切り離したい。なんでもしますから! というわけでちゃんと設計練って書いてみたら結構いいんじゃねとなったので、解説書く。 設計の概要 EventSource#createEvents() は Eventの配列を生成する 実際にはここがユーザーが記述する部分になる EventRunner はループ毎にEventSource#createEvents()を呼び、上から順に処理する event.eventType毎に処理の仕方を記述する この例ではEvent間の時間を100msとなるよ]うにしてるが、実際なんでもいい。 コード CoffeeScriptで
Learning promises is an interesting process. Like many tools, there are common pitfalls to get stuck on. What makes promises somewhat unique is that it tends to be obvious that you're doing it wrong. Why? Promises are designed to solve a clear and well-understood problem: nested callbacks. As you start to use them however, you're code isn't that different. Obviously there's something you don't gro
You've probably heard the talk around the water cooler about how promises are the future. All of the cool kids are using them, but you don't see what makes them so special. Can't you just use a callback? What's the big deal? In this article, we'll look at what promises are and how you can use them to write better JavaScript. Promises are Easier to Read Let's say we want to grab some data from the
はじめに この記事は、 JavaScript/ES6 promisesについてを理解するために読んだ方がよいと思われる記事やスライド等を紹介しています。 PromisesやDeferredといった言葉を非同期処理の話などで聞いた事があるかもしれませんが、 現在Promisesは次のECMAScriptの言語仕様として策定が進められています。 ECMAScript Language Specification ECMA-262 6th Edition – DRAFT domenic/promises-unwrapping まだES6は策定段階ですが、既にPromisesについてはpolyfillとして利用できるライブラリ等もあり、また他のライブラリ内でもjQuery.Deferred()やAngularの$q等類似する実装が存在します。 そのため、Generators等に比べると今すぐ使える
リリース、障害情報などのサービスのお知らせ
最新の人気エントリーの配信
処理を実行中です
j次のブックマーク
k前のブックマーク
lあとで読む
eコメント一覧を開く
oページを開く