HTML 5 Learning notes for those attributes that are often ignored

Before learning HTML5, the mentality is more impetuous, now Ann down to look carefully HTML5, really have a lot of better properties are often ignored, at least I was rarely used.

1, accesskey, supported tags are <a> <area> <button> <input> <textarea> <label> < Lagend> (form labels and link labels) are supported by browsers other than opera.

Use Alt + AccessKey (or Shift + ALT +AccessKey) to access the element with the specified shortcut key.

2, contenteditable, specifies whether editable elements, Boolean properties, unsupported browsers have IE (IE11) Firefox.

3, ContextMenu, temporarily no browser support. According to the example given by W3school, the value of ContextMenu is the ID value of <menu>, so that by right-clicking, it pops up the set up and down content.

4, data-*, this property allows us to customize the property content. In JavaScript, you can get the value of a custom setting by element.dataset["*".

5,media, which is a descriptive property, describes what kind of device the target URL is optimized for, so it can only be used if there is an href. Attribute values See http://www.w3school.com.cn/tags/att_a_media.asp

6,lang,hreflang, which is the language (global attribute) that defines the content of the element, which is the language that specifies the document to be connected. Whether to specify this property, in the Web page does not appear, this is mainly for the search engine and implementation of the specification, tell the search engine, this is an English

7,target, in addition to the _blank,_self,_top,_parent that we often use or see, can also be specified as the value of the Name property of <iframe> in the current page so that the connected site opens in the frame.

8,preload, mainly used for audio and video, has three values, None,auto,meta. If AutoPlay is specified, there is no point in defining the preload attribute.

None: Preload is not done. With this property value, it is possible that the page author believes that the user does not expect this video, or reduces the HTTP request.

Meta: Partially preloaded. Use this property value to represent the page author that the user does not expect this video, but to provide some metadata (including dimensions, first frame, track list, duration, and so on) to the user.

Auto: Pre-load all.

The Value property in 9,<button>, W3school says that the text in the middle of the button is committed in IE, not the values of Value property, but this problem should be solved in IE11. Http://www.w3school.com.cn/tags/tag_button.asp

10,name, there are two functions, one is sent with value, one is labeled itself, and in radio for grouping.

11,<embed> SRC, can explain. Swf,.jpg, cannot interpret audio video files.

After the seamless property of the 12,<iframe> is specified, the contents of the frame have no border and scroll bars.

The Usemap property of the 13, is treated as an image-specific image map, whose value refers to the name or ID value of <map>.

The Accept property in 14,<input>, when type= "file" is valid, its value is Mime_type, after the specified acceptable type, click on upload the default pop-up window displays only the uploaded files, such as setting accept= "image/*" The file of the pop-up window can be selected all the picture class files.

A 15,pattern that specifies the regular expression of the input content.

The property value of the start of 16,<ol> is a number, for example, it is set to a value of 10, then the arrangement starts from 10, and when Type= "A" is set, it is arranged from the tenth letter.

The Label property in 17,<option> is not supported by Firefox. The value of the label after it is set overrides the value in <option></option>.

18,async & Defer:

If async= "Async": The script executes asynchronously relative to the rest of the page (the script will be executed when the page resumes parsing)

If Async is not used and defer= "defer": the script executes when the page finishes parsing

If neither async nor defer is used: reads and executes the script immediately before the browser continues to parse the page

HTML 5 Learning notes for those attributes that are often ignored