使用Javascript生成的网站的优点/缺点

Question

Two good examples would be google and facebook .

I have lately pondered the motivation for this approach. My best guess would be it almost completely separates the logic between your back-end language and the markup. Building up an array to send over in JSON format seems like a tidy way to maintain code, but what other elements am I missing here?

What are the advantages / disadvantages to this approach, and why are such large scale companies doing it?

Answer 1

The main disadvantage is that you have some pain with content indexation of your site.

For Google you can somewhere solve the problem by using Crawling scheme. Google supports crawling that allows you to index dynamically (without page reload) generated content of your page.

To do this your virtual links must be addresses like so: http://yoursite.com/#!/register/ . In this case Google requests to http://yoursite/register/ to index content of the address.

When clicking on virtual link there is no page reload. You can provide this by using onclick :

<a href='http://yoursite.com/#!/register/' onclick='showRegister()'>Register</a>

Virtual advantage is that content of a page changed without reloading of the page. In my practice I do not use Javascript generation to do this because I build my interface in fixed positions. When page reloads user does not notice anything because elements of the interface appears in expected places.

So, my opinion that using of dynamic page generation is a big pain. I think Google did it not to separate markup and backend (it's not a real problem, you can use complex structure of backend-frontend to do that) but to use advantages of convenient and nice representation for users.

Answer 2

Advantages

• View state is kept on the client (removing load from the server)
• Partial refreshes of pages
• Server does not need to know about HTML which leads to a Service Oriented Architecture

Disadvantages

• Bookmarking (state in the URL) is harder to implement
• Making it searchable is still a work in progress
• Need a separate scheme to support non-JS users

Answer 3

I don't 100% understand your question, but I'll try my best here...

Google and Facebook both extensively use JavaScript across all of their websites and products. Every major website on the web uses it.

JavaScript is the technology used to modify the behavior of websites.
HTML => defines structure and elements

CSS => styling the elements

Scripting languages => dynamically generating elements and filling them with data

JavaScript => modifies all of the above by interacting with the DOM, responding to events, and styling elements on the fly

This is the 'approach' as you call it to every website on the web today. There are no alternatives to JavaScript/HTML/CSS. You can change the database or scripting language used, but JavaScript/HTML/CSS is a constant.

Answer 4

Consider an example of a simple form validation ...

client sends a request to a server ... the server will execute the server side code containing validation logic and in a response ...the server will send the result to the client ....

if the client has the capability to execute/process (that can be executed on the client side ...) the form ...(perform validation)..the client wont need send request to the server ...and wait for the server to respond to that request ...

Answer 5

我建议你看一下Google Page Speed最佳做法http://code.google.com/intl/it-IT/speed/page-speed/ ，了解制作好网页的因素是什么...由于ui和逻辑的分离，使用javascript的页面似乎很酷，但在实践中它是完全低效的