量角器中的'$'选择器 [英] '$' selector in Protractor

问题描述

我在许多示例中都看到过这样的$('.selector')，并且我也在使用它.那么此 $ 变量的作用是什么.这是我从量角器 docs 中得到的.

I have seen in many examples like this $('.selector') and I am also using this. So what this $ variable does. This is what I got from the protractor docs.

对$的调用可以链接在一起，以在父级中查找元素.

Calls to $ may be chained to find elements within a parent.

在文档中没有单独使用$的示例.我们正在使用$与element选择器链接.

There is no example in docs which use $ alone. We are using $ to chain with element selector.

$('.selector')本身也是一个元素，当我们执行此element($('.selector'))时，这是一个错误.

Also $('.selector') itself is an element, when we does this element($('.selector')), it is an error.

所以如何在量角器中使用此$选择器.它具有JQuery $的所有功能吗?我尝试了$('.selector').children，说children不是函数.

So how to use this $ selector in protractor. Does it have all the features of JQuery $. I tried $('.selector').children which says children is not a function.

非常感谢您的帮助.

谢谢！

推荐答案

外观类似于jQuery语法，但事实并非如此，它是量角器的一部分.这就是.children抛出错误的原因，因为我们实际上并未使用jQuery. $是element(by.css())的简写版本，即

That looks like jQuery syntax but it is not, it's part of Protractor. That's why .children is throwing an error because we're not actually using jQuery. $ is a shorthanded version of element(by.css()) i.e.

$('my-css');与element(by.css('my-css'));

它们还具有与element.all(by.css())相同的$$

尽管缺少文档，但不是 必须使用进行链接以查找子元素.即使用Julie的量角器演示程序(我修改了示例):

Despite the lack of documentation, it does not have to be used for chaining to find child elements. i.e. using Julie's protractor demo (I modified the example):

describe('Protractor Demo App', function() {
  it('read the header', function() {
    browser.get('http://juliemr.github.io/protractor-demo/');
    $('h3').getText().then(function (val) {
      console.log(val);
    });
  });
});

这会打印出我所在的h3元素的标题. $和$$只是CSS选择器的简写.

That prints out the title of the h3 element that I located. The $ and $$ are simply a shorthand for css selectors.

来源:此处为$$ ， 此处为$ 和这也是我找到的不错的文档(尽管它没有提到使用$$: http://luxiyalu.com/protractor-locators-selectors/

Also this is a nice document I found (though it does not mention the use of $$ : http://luxiyalu.com/protractor-locators-selectors/

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