) Details about the LINK rel and target

The issue of target = "_ blank" has been repeatedly controversial on the Internet for many times. Some say they want to stay, some say they want to remove them. The main reason for retaining the claim is that the target = "_ blank" attribute does not have a good solution yet, while the claimant uses the rel and JS solutions. Target = "_ blank" whether it is necessary or not. I think there are still many blind spots. After reading the relevant literature, I found that the actual situation is not what we think. In fact, target = "_ blank" is not against the standard, there is no need to use Rel and JS solutions, because this is a misunderstanding. As long as we understand the true meaning of Rel and target, we know that there should not be any controversy here. Next, I will share with you the knowledge I have obtained through literature review. Let's first understand the meaning of target and rel:

Target, which allows you to specify the position where the selected hyperlink content is displayed. In other words, the content of the link will be displayed in a window. The target attribute values have four Reserved names: _ blank, _ Self, _ parent, and _ top. Where_ BlankIt means that the browser always loads the target = "_ blank" link document in a new and untitled window. Here, we may not understand what "Untitled" means. In fact, target is an ID that can be assigned to a new window. For example: target = "name" indicates that the document loaded through the target = "name" link will be displayed in a window named "name. If there is no window with ID "name", the browser will create a window named "name" to display the link document. If the ID of the current window is "name", the link document will replace the original content in the current window. While_ Self<A> the default target is _ Self. This attribute value is generally unavailable._ ParentIs to display the link document in the parent window. This attribute value is only used in the framework structure. If it is a top-level framework, it serves the same purpose as _ self._ TopIt is also applied in the framework, but its effect is to clear the framework to display the target document. This is very useful for switching from a framework structure to a non-framework structure.

Now we know that target is the property of a target that is closely related to the browser. So what is rel? Why do many people regard it as an alternative attribute of target? Next, let's get to know Rel. In fact, there is not only oneRELThere is also a corresponding property calledRevThese two attributes mean the relationship between the source document and the target document, and from the target document to the source document. The source document here can be understood as the current document where the link is located, and the target document is the document to be opened. Now we should know that Rel and Rev are links to the previous document, rather than how to display the properties of the target document related to the browser.

So what is the relationship between rel and Rev? The following describes the meaning of the column:

Next, link to the next document;
PREV: Link to the previous document;
Head: Link to the top-level documents in the set;
TOC, which is linked to the directory of the set;
Parent, link to the source document;
Child, link to the document below the source;
Index, the index linked to this document;
Glossary, which is linked to the glossary of this document;

Here, next and Prev are a group. Indicates that the relationship between the current document and the target document is the same level. You can write it as <a href = "movie_002.htm" rel = next REV = Prev>. A combination of head and TOC can be formed to indicate that a directory is linked to the final document or a document is linked to a directory. A group of parent and child indicates that the current document is linked to the parent or child document. The index and glossary can be combined with the head to form a document to the index, or from the index to the document; from the document to the glossary or glossary to the document.

It may not be clear to say this. The following is an example: I have sorted out a file resource for a movie, so I need to classify these resources. I divide the movie: martial arts films, war films, love films, terrorism films, and documentaries. When the root directory of a movie needs to be linked to the following sub-classes, the link should be: rel = Child REV = parent. If it is the channel page of the martial arts film, when I want to transfer a love film channel or other channels, the link should be: rel = next REV = Prev, when we use a martial arts film to link to the "Crouching Tiger, Hidden Dragon" movie document, the link should be: rel = head REV = toc, when "Crouching Tiger, Hidden Dragon" is linked to the index, the link becomes: rel = index REV = head.

Currently, CSS cannot capture the attribute values of Rel and Rev, so there is no way to provide different styles for links with different relationships, so now Rel and Rev are only used to make the semantics of web pages more complete.