包裹异步JavaScript函数的模式，使其成为同步的。

本文是小编为大家收集整理的关于包裹异步JavaScript函数的模式，使其成为同步的。的处理/解决方法，可以参考本文帮助大家快速定位并解决问题，中文翻译不准确的可切换到English标签页查看源文。

中文
English

问题描述

我正在使用JavaScript API，其中大多数功能都是异步的. API是 webkit这是与操作SQLITE3 数据库的功能子集的结合.我了解将事物异步的设计决定，以免阻止并提供响应迅速的用户界面.在我的情况下，我知道我对异步API调用的使用将很快执行.由于这种情况，我想为开发人员提供更清洁，更易于使用的包装API，该API强迫同步通话.

这是异步调用

db.executeSql(sqlStatement, function(result) {
  // do something with result
});

这就是我想做的

var result = dbWrapper.executeSql(sqlStatement);
// do something with result

是否有设计模式/方法?优选的书面或链接到代码示例. Target Platform/Broswer是iPhone上的移动野生动物园.

谢谢

其他推荐答案

stratifiedjs允许您做到这一点.

甚至还有一篇有关如何将其应用于浏览器存储的文章: http://onilabs.com/blog/blog/stratifying-stratifying-asstratifying-ashratifying-ashonchronous-storoge

这是分层的javascript库，它使用 https://gist.github.com/613526

示例就像:

var db = require("webdatabase").openDatabase("CandyDB", ...);
try {
  var kids = db.executeSql("SELECT * FROM kids").rows;
  db.executeSql("INSERT INTO kids (name) VALUES (:name);", [kids[0]]);
  alert("done");
} catch(e) {
  alert("something went wrong");
}

也许有点晚，但是当时的技术不存在;)

其他推荐答案

您可以尝试以下操作:

function synch()
{
    var done = false;
    var returnVal = undefined;

    // asynch takes a callback method
    // that is called when done
    asynch(function(data) {
        returnVal = data;
        done = true;
    });

    while (done == false) {};
    return returnVal;
}

，但这可能会在异步方法的持续时间内冻结您的浏览器...

或查看叙述性javascript:叙事JavaScript是JavaScript语言的小扩展，可为异步事件回调提供阻止功能.这使得异步代码令人耳目一新且可理解.

http://neilmix.com/narrmix.com/narrativejs/doc/doc/doc/index.htex.html

Mike

本文地址：https://www.itbaoku.cn/post/627682.html

百度翻译此文有道翻译此文

问题描述

I'm working with a JavaScript API where most of the functions are asynchronous. The API is the WebKit JavaScript Database API which is a binding to a subset of functionality to manipulate SQLite3 databases. I understand the design decision to make things async as to not block and provide a responsive user interface. In my situation I know that my usage of the async API calls will execute fast. Since this is the case I'd like to provide my developers a cleaner and easier to use wrapper API that forces synchronous calls.

Here's the async call

db.executeSql(sqlStatement, function(result) {
  // do something with result
});

And here's what I'd like to be able to do

var result = dbWrapper.executeSql(sqlStatement);
// do something with result

Is there a design pattern/way to do this? A written or linked to code example is preferred. The target platform/broswer is Mobile Safari on the iPhone.

Thank you

其他推荐答案

StratifiedJS allows you to do exactly that.

There's even an article on how to apply it on browser storage: http://onilabs.com/blog/stratifying-asynchronous-storage

And this is the Stratified JavaScript library it uses https://gist.github.com/613526

The example goes like:

var db = require("webdatabase").openDatabase("CandyDB", ...);
try {
  var kids = db.executeSql("SELECT * FROM kids").rows;
  db.executeSql("INSERT INTO kids (name) VALUES (:name);", [kids[0]]);
  alert("done");
} catch(e) {
  alert("something went wrong");
}

maybe a bit late, but the tech didn't exist back then ;)

其他推荐答案

You can try something like:

function synch()
{
    var done = false;
    var returnVal = undefined;

    // asynch takes a callback method
    // that is called when done
    asynch(function(data) {
        returnVal = data;
        done = true;
    });

    while (done == false) {};
    return returnVal;
}

But that may freeze your browser for the duration of the asynch method...

Or take a look at Narrative JavaScript: Narrative JavaScript is a small extension to the JavaScript language that enables blocking capabilities for asynchronous event callbacks. This makes asynchronous code refreshingly readable and comprehensible.

http://neilmix.com/narrativejs/doc/index.html

Mike

上一篇：Java单子模式

下一篇：什么是WPF应用程序中使用的 "弱事件 "模式？