EmberJS / HandlebarsJS的自定义for-loop帮助器 [英] Custom for-loop helper for EmberJS/HandlebarsJS

问题描述

两小时前一小时，我开始：嵌套HandlebarsJS＃每个助手EmberJS不工作

A small two hours ago I started: Nested HandlebarsJS #each helpers with EmberJS not working

我自己想到一个可接受的临时解决方案后不久，问题仍然没有得到解决。我的问题并不止于此。

Shortly after I figured an acceptable temporary solution myself, question is still unaswered. My problems didn't stop there though.

我现在正在尝试创建一个自定义帮助器，它将循环遍历一个对象数组，但不包括第一个索引 - 相当多的 i = 1; i< length; i ++）{} 。我已经在网站上阅读过您需要获取上下文长度并将其传递给选项 - 考虑到您的函数如下所示： forLoop（context，options）。

I am now trying to make a custom helper which will loop through an array of objects, but exclude the first index - pretty much: for(i = 1; i < length; i++) {}. I've read on websites you have to get the length of your context and pass it to options - considering your function looks like: forLoop(context, options).

然而，上下文是一个字符串而不是一个实际的对象。当您执行 .length 时，您将获得字符串的长度，而不是数组的大小。当我将它传递给选项时，没有任何反应 - 不要太提及浏览器冻结。

However, context is a string rather than an actual object. When you do a .length, you will get the length of the string, rather than the size of the array. When I pass that to options, nothing happens - not too mention browser freezes.

然后我首先尝试一个 getPath 在将其传递给选项之前，这将返回一个空字符串。

I then first tried to do a getPath before passing it to options, this returns an empty string.

我应该做什么，而之前我做了for循环代码，只是HandlebarsJS，工作，但是EmberJS似乎没有这样做，为什么？

What am I supposed to do instead, I made the for-loop code before for just HandlebarsJS and that worked, but EmberJS doesn't seem to take it, why?

编辑：我也很遵循： http://handlebarsjs.com/block_helpers.html - >简单迭代器

I pretty much also followed: http://handlebarsjs.com/block_helpers.html -> Simple Iterators

推荐答案

在尝试了很长时间后，我自己解决了这个问题。

I solved this myself after trying for a long time.

HandlebarsJS方法（如网站上所述）不再适用于EmberJS，现在如下：

The HandlebarsJS method (as described on the site) is no longer valid for EmberJS, it's now as follows:

function forLoop(context, options) {
    var object = Ember.getPath(options.contexts[0], context);
    var startIndex = options.hash.start || 0;

    for(i = startIndex; i < object.length; i++) {
        options(object[i]);
    }
}

哎，你甚至可以将for循环扩展到包含一个索引值！

Heck, you could even extend the for-loop to include an index-value!

function forLoop(context, options) {
    var object = Ember.getPath(options.contexts[0], context);
    var startIndex = options.hash.start || 0;

    for(i = startIndex; i < object.length; i++) {
        object[i].index = i;

        options(object[i]);
    }
}

这是一个可变起始索引的工作for循环。您可以在模板中使用它：

This is a working for-loop with variable start index. You use it in your templates like so:

{{#for anArray start=1}}
    <p>Item #{{unbound index}}</p>
{{/for}}

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