Underscore _.each回调完成后？ [英] Underscore _.each callback when finished?

问题描述

当下划线完成时是否有回调它是 _。每个循环，因为如果我控制台日志之后立即显然我用每个循环填充的数组不可用。这是来自嵌套的 _。每个循环。

Is there a callback for when underscore is finished it's _.each loop because if I console log immediately afterwards obviously the array I am populating with the each loop is not available. This is from a nested _.each loop.

_.each(data.recipe, function(recipeItem) {
    var recipeMap = that.get('recipeMap');
    recipeMap[recipeItem.id] = { id: recipeItem.id, quantity: recipeItem.quantity };
});
console.log(that.get('recipeMap')); //not ready yet.

推荐答案

每个 函数是同步的，完成时不需要回调。其中一个在循环之后立即执行命令将执行。

The each function in UnderscoreJS is synchronous which wouldn't require a callback when it is finished. One it's done executing the commands immediately following the loop will execute.

如果您在循环中执行异步操作，我建议使用支持异步操作的库。每个功能。一种可能性是使用 AsyncJS 。

If you are performing async operations in your loop, I would recommend using a library that supports async operations within the each function. One possibility is by using AsyncJS.

这是你的循环转换为AsyncJS：

Here is your loop translated to AsyncJS:

async.each(data.recipe, function(recipeItem, callback) {
    var recipeMap = that.get('recipeMap');
    recipeMap[recipeItem.id] = { id: recipeItem.id, quantity: recipeItem.quantity };
    callback(); // show that no errors happened
}, function(err) {
    if(err) {
        console.log("There was an error" + err);
    } else {
        console.log("Loop is done");
    }
});

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