一种制造角滤波器条件 [英] Making an angular filter conditional

问题描述

我目前使用的文本输入来过滤项的列表。我想使它所以当一个特定的变量设置，列表不会过滤，无论文本输入是什么。我如何能做到这一点有什么建议？

 ＆LT;一个NG重复=数据集|过滤器：{值：搜索}数据ID ={{set.id}}NG-鼠标按下= setBox（设置）NG-鼠标悬停=的setSelected（套，$事件）NG绑定-HTML =set.value | trustHTML＆GT;＆LT; / A＆GT;
 

解决方案

可以做到这一点，如果你设置过滤器前pression到（或未定义） - 这会导致过滤器不适用 - 当你的 disableFilter 设置，或实际过滤前pression否则

因此​​，假设，这种切换变量 - disableFilter - 是一个布尔值：

 ＆LT;一个NG重复=数据集|过滤器：（！disableFilter ||''）及和放大器; filterEx pression＆GT;
 

（用 filterEx pression 是要过滤通过任何除权pression）。您的具体情况是：

 ＆LT;一个NG重复=数据集|过滤器：（disableFilter ||''！）及和放大器; {值：搜索}＆GT;
 

编辑：

要解释以上是如何工作的。

1. 记住 || 和＆放大器;＆安培; 返回它的其中一个操作数的值


2. || 和＆放大器;＆安培; 使用短路评价 - 真| | （任何）收益真正; 假放;＆安培; （任何）收益假 - 无需评估（任何）前pression


3. 是falsy（或使用未定义相反，如果它更清晰）

因此​​，

在 disableFilter ===真正，！disableFilter ===虚假，这样的第二个操作数 || - 空字符串！ - 评估（这是falsy）和（disableFilter ||''）收益 - 一个falsy值，短路＆放大器;＆安培; 操作，不评估＆放大器的第二个操作数;＆安培; 。恩pression的返回值是这样。

在 disableFilter ===虚假，！disableFilter ===真正，其中短路 || 操作，那么＆放大器的第二个操作数;＆安培; 评估并返回。恩pression的返回值是这样 {值：搜索}

了解更多关于<一个href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_Operators\">logical这里运营商

I'm currently using a text input to filter a list of items. I'd like to make it so when a particular variable is set, the list doesn't filter, regardless of what the text input is. Any advice on how I can accomplish this?

<a ng-repeat="set in data | filter: { value: search }" data-id="{{set.id}}" ng-mousedown="setBox(set)" ng-mouseover="setSelected(set, $event)" ng-bind-html="set.value | trustHTML"></a>

解决方案

You can achieve this if you set the filter expression to '' (or undefined) - this causes the filter not to be applied - for when your disableFilter is set, or to the actual filter expression otherwise.

So, assuming, this toggling variable - disableFilter - is a boolean :

<a ng-repeat="set in data | filter: (!disableFilter || '') && filterExpression">

(with filterExpression being whatever the expression you want to filter by). Your specific case would be:

<a ng-repeat="set in data | filter: (!disableFilter || '') && {value: search}">

EDIT:

To explain how the above works.

1. Remember that || and && return the value of one of its operands.
2. || and && use short-circuit evaluation - true || (anything) returns true; false && (anything) returns false - without evaluating the (anything) expression.
3. '' is falsy (or use undefined instead, if it's clearer)

And so,

when disableFilter === true, !disableFilter === false, thus the second operand of || - the empty string '' - is evaluated (it's falsy), and (!disableFilter || '') returns '' - a falsy value, which short-circuits the && operation and does not evaluate the second operand of &&. The return value of the expression is thus ''.

when disableFilter === false, !disableFilter === true, which short-circuits the || operation, then the second operand of && is evaluated and returned. The return value of the expression is thus {value: search}.

Read more about logical operators here

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