Shulou(Shulou.com)06/03 Report--

This article mainly introduces "what are the advantages and disadvantages of Ajax". In daily operation, I believe many people have doubts about the advantages and disadvantages of Ajax. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful to answer the doubts about "what are the advantages and disadvantages of Ajax?" Next, please follow the editor to study!

Advantages of ajax

Basically, we all have a deep understanding of the benefits brought to us by Ajax. Here, I will just briefly talk about a few points:

1. The biggest point is that the page has no refresh and communicates with the server within the page, which gives the user a very good experience.

2. Communicate with the server asynchronously, without interrupting the user's operation, and have more rapid response ability.

3. We can transfer the work of some previous servers to the client, make use of the idle ability of the client to deal with it, reduce the burden of the server and bandwidth, and save space and broadband rental costs. And reduce the burden on the server, ajax's principle is to "fetch data on demand", which can minimize the burden of redundant requests and responses on the server.

4. Based on standardized and widely supported technology, there is no need to download plug-ins or Mini Program.

Shortcomings of ajax

Next, I would like to focus on the shortcomings of ajax, because most of us usually pay attention to the benefits that ajax brings to us, such as the enhancement of user experience. However, the defects brought by ajax are ignored.

The defects of ajax described below are all caused by it.

1. Ajax kills the back button, which destroys the browser's fallback mechanism. The back button is an important feature of a standard web site, but it doesn't work well with js. This is a serious problem caused by ajax, because users often want to be able to cancel the previous operation by going back. So is there any way to solve this problem? The answer is yes, as those who have used Gmail know that the ajax technology adopted under Gmail solves this problem and can be retreated under Gmail, but it does not change the mechanism of ajax, it just uses a relatively stupid but effective way, that is, when the user clicks the back button to access the history, create or use a hidden IFRAME to reproduce the changes on the page. (for example, when the user clicks back in Google Maps, it searches in a hidden IFRAME and then reflects the search results on the Ajax element to restore the application state to its current state. However, although this problem can be solved, the development cost is very high, which is contrary to the rapid development required by the ajax framework. This is a very serious problem brought about by ajax.

2. Security problem technology also brings new security threats to IT enterprises. Ajax technology is like establishing a direct channel for enterprise data. This allows developers to inadvertently expose more data and server logic than ever before. The logic of ajax can be hidden from the client's security scanning technology, allowing hackers to establish new attacks from remote servers. And ajax is also difficult to avoid some known security vulnerabilities, such as cross-site footprint attacks, SQL injection attacks and credentials-based security vulnerabilities.

3. The support for search engine is weak.

4. Destroy the exception mechanism of the program. At least for now, ajax frameworks like ajax.dll,ajaxpro.dll can break the exception mechanism of the program. I have encountered this problem in the process of development, but I checked that there are few relevant introductions on the Internet. Later, I did an experiment myself, using ajax and traditional form submission mode to delete a piece of data. It brings great difficulties to our debugging.

5. In addition, like some other issues, such as violating the original intention of url and resource positioning. For example, I give you an url address, and if you use ajax technology, what you see under that url address may be different from what I see under this url address. This deviates from the original intention of resource positioning.

6. Some handheld devices (such as mobile phones, PDA, etc.) do not support ajax very well. For example, when we open a website using ajax technology on a mobile browser, it does not support it at present. Of course, this problem has nothing to do with us.

At this point, the study of "what are the advantages and disadvantages of Ajax" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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