Justin's Words

Posted on | In |

有一个容器：

1
2
3
4
5
6
7
<div class="container">
    <item class="item"></item>
    <item class="item"></item>
    <item class="item"></item>
    <item class="item"></item>
    <item class="item"></item>
</div>
Read more »
Justin's Words

Posted on | In |

现在有如下 HTML：

1
2
3
<div class="module">
    <p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.</p>
</div>

设置多行限制为省略号如下：

1
2
3
4
5
6
7
8
9
10
.module {
    width: 250px;
    overflow: hidden;
}

.line-clamp {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
}

设置宽度限制为省略号如下：

1
2
3
4
5
6
.module {
    width: 250px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
Justin's Words

Posted on | In | 
1
2
3
var URL_REGEXP = /^(http|ftp|https):\/\/[\w\-_]+(\.[\w\-_]+)+([\w\-\.,@?^=%&:/~\+#]*[\w\-\@?^=%&/~\+#])?$/;
var url = "https://g.taobao.com/brand_detail.htm?navigator=all&_input_charset=utf-8&q=%E7%94%B7%E5%A3%AB%E8%A1%AC%E8%A1%AB%E8%8B%B1%E4%BC%A6%E6%AC%BE&spm=5148.1292865.a31d2.2.NiXIQv";
URL_REGEXP.test(url);    // true
Read more »
Justin's Words

Posted on | In |

来自：Is object empty?

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
// Speed up calls to hasOwnProperty
var hasOwnProperty = Object.prototype.hasOwnProperty;

function isEmpty(obj) {

    // null and undefined are "empty"
    if (obj == null) return true;

    // Assume if it has a length property with a non-zero value
    // that that property is correct.
    if (obj.length > 0)    return false;
    if (obj.length === 0)  return true;

    // Otherwise, does it have any properties of its own?
    // Note that this doesn't handle
    // toString and valueOf enumeration bugs in IE < 9
    for (var key in obj) {
        if (hasOwnProperty.call(obj, key)) return false;
    }

    return true;
}

underscore.js 对此有专门的函数判断，为 _.isEmpty()。

Justin's Words

Posted on | In |

理解 AngularJS 的 $watch()。

$watch(watchExpression<string|Function(scope)>, listener, [objectEquality])

$watch() 可以接受两个函数作为参数，第一个参数数返回监控的 $scope 的变量，第二个函数操作该变量的旧值和新值，第三个参数是可选的，类型为 Boolean，true 则表明第一个参数返回的是一个对象，默认为 false，结构：

1
2
3
4
$scope.$watch(function (scope){
    return scope.variable;
}, function (newValue, oldValue) {
});
Read more »