September 2022
Intermediate to advanced
585 pages
8h 17m
Chinese
Content preview from JavaScript 经典实例：第三版
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334
｜
第
12
章
minlength
和
maxlength
字符串输入框的最小长度和最大长度。
pattern
在输入框内输入的内容必须满足的正则表达式。
required
提交表单之前必须填写的输入框。
type
让开发人员指定输入框的内容类型，例如日期、电子邮件地址、数字、密码、
URL
，或者其他预设的特定类型。
另外，可以使用
CSS
伪选择符匹配
:valid
和
:invalid
输入框。
因此，简单的表单可能完全不需要使用
JavaScript
。如果你想进一步控制表单验
证的外观和行为，最好使用
JavaScript
库，不要依赖
HTML5
和
CSS
表单验证规
范。如果你想为表单添加无障碍功能，笔者建议阅读
WebAIM
网站中的“
Creating
Accessible Forms
”一文（
https://oreil.ly/5oL3E
）。
12.17
突出显示表单错误并符合无障碍功能要
求
12.17.1
问题
你想突出显示数据有错误的表单字段，并确保突出效果对所有网页用户都行之有效。
12.17.2
方案
使用
CSS
突出显示输入错误的表单字段，并使用
WAI-ARIA
（
Web Accessibility
Initiative-Accessible Rich Internet Applications
）标记，确保突出效果对所有用户都
清晰明了。
处理
HTML
｜
335
[
aria-invalid
] {
background-color
: #f5b2b2;
}
为需要验证的表单字段依附一个
oninput
事件处理函数，检查字段的值是否有效。 ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.