Why are .html file parsed rather than compiled when open them in browser such as Safari? From the internet, I learned that parser is a component of a compiler. People say .html is parsed to a web page, but why not compiled to a web page? .html file contains code that needed to be compiled so that it becomes a webpage, right?
Some possible reasons: Maybe when we say something is compiled, it has to be compiled into machine language but .html does not?
HTML does not get compiled - it simply describes how the website should be rendered.
And that is then interpreted by the browser - it doesn't end up as machine code.
It's like a map or blue prints telling the browser's rendering engine how to build the website.
The W3C defines how these "plans" should be written and the browser vendor should make sure they interpret the plans in the correct way.
Developers should make sure they use the HTML elements properly so that the HTML files make sense and the browser can construct the web page properly.
What difference does it make? You have not described a problem you are having.
The parsing of HTML is application-dependent. Each browser/parser decides how to do it.
HTML however must be dynamically modifiable. Since HTML is not executed, it is not clear what the difference is between compiling and interpreting but typically compiled code can't be easily modified.
JavaScript is by definition interpreted.
Related
I know it's not a good question to ask, but sometimes I really need to know if a webpage or website is static or not.
Sometimes I see .html extension in many URL, Does that mean that those pages are static?
.html extension means that page contains only front-end code and does not have any server side language included in it (I'm not talking about URL rewriters that adds .html to the end of virtual path).
This does not prevent these things:
Page can load it's content via Ajax depending on inputs, URL params, time of day, etc.
Page can be generated as static HTML page, but still be re-generated from time-to-time.
You can have iFrame in static HTML page that leads to .php file.
Not really, .html does not mean webpage is static. Ajax can be used to load dynamic data in html page.
Also there is no proper method defined to find whether page is static or dynamic.
One way is, you can check requests in Developer Options of browser.
You can read more here.
No.
There is no guarantee of a direct relationship between a thing that looks like a file extension in a URL and how the server handles things behind the scenes.
It might be resolved using basic static file handling rules to a static file with that name.
It might use a tool like mod_write to map the URL onto a server side script with the same name but a different file extension (e.g. if the site used to be made of static files, but was changed to be dynamic with steps taken to keep the URLs unchanged).
It might use a tool like mod_write to map the URL onto a server side script that has no relation to the name of the file but implements the front controller pattern for the whole site.
It might map onto a server side script which looks at the end of the URL to determine what type of data to return the content in (e.g. cars.html and cards.json might both be be handled by the same script, which outputs a list of cars, but it might output it in JSON or HTML depending on the URL).
It might hit a 404 error or a 302 redirect.
It might do any number of other things.
Not always, sometimes it can be a generated page from a Servlet or a PHP script that generates them. you can have a .htaccess rule to add .html to all documents.
Using Delphi XE6, I've written lots of service applications that use TIdHTTPServer. Every now and again, a javascript file will fail to load in Firefox, and when I check the Delphi application's log, there's no mention of it.
Example:
In TIdHTTPServer.OnCommandGet, first thing I do is log the requested page. After the page loads in Firefox, the log shows the page request, 3 CSS requests and 3 JS requests - for this example it is correct. But sometimes, and it's usually after I haven't requested the page for a while, despite closing Firefox, and the Delphi service application, one of the JS requests is missing, and it's not loaded in Firefox, so things don't work.
Not sure if it's relevant, but one of the techniques I use is appending the file's last modified timestamp code as a parameter when requesting the file.
eg. in the HTML, it will say <script type="text/javascript" src="general.js?rnd=20150522155113"></script>
I do this to ensure updates to JS and CSS files are always reloaded and not cached.
I'm not sure how to go about solving this. The issue affects multiple delphi projects. I only use Firefox, so not sure if other browsers are affected. Any help is appreciated.
I have an mvc razor app that's humming along nicely, and I just tried to drop in a static html Terms and Conditions page. When I try to link to it from my opt-in cshtml with
Terms and Conditions
It 404s at runtime with "resource cannot be found".
It's in the compiled folder. The path and name are correct (I picked it with intellisense, so it knows it's there). The link cshtml page and destination html page are even in the same folder (I've tried using just the filename too).
It's just plain html. It shouldn't need any fiddling with routing or anything. Why can't it find it?
~/Views is inaccessible by default and ~ doesn't work in static HTML, you can use this and it should get you the relative path and work
Put your static HTML file in ~/Content/UserPromotion
and use
Terms and Conditions
I am struggling to get some performance in my MVC application.I am loading a partial page (popup) which is taking hardly 500ms. But each time the popup loads it also downloads 2 jQuery files as well.
is it possible to use the jQuery from cache or from parent page?
I have attached the image in red which shows 2 additional request to server.
In order to improve the performance you can try with the following approaches:
see if your application server supports GZip and configure the application/server to return the responses always archived in Gzip
Use minified version of JQuery
there are also Packing libraries where you can pack all the imported resources, such as CSS files and JS files, and the browser will do only 1 request per resource type. For instance, in Java we have a library called packtag.
In general, I recommend you using Google Chrome browser and its performance analyzer. It will give you good hints.
In the Bundle config use this code
BundleTable.EnableOptimizations = true;
and also indclude both files in single bundle.
Does the popup use an iframe or does it's content just get added to the DOM of the current page?
If it gets added to the current page you could try just adding the script references to the parent page instead. It might not always be the best idea if the parent page has no need for those two files, but if the parent page also uses the jQuery validation then the popup will be able to use the parent's reference to the script file.
For an iframe I'd suggest looking at Gzip and minification to make the scripts load faster.
When debugging my MVC3 app in Visual Studio using IE9 I see lots of small "script block" entries for my page. My page relies heavily on AJAX, and some actions result in replacing sections of the DOM with partial views coming back from the server.
What I'm seeing is a growing list of these "script block" entries - should I be worried about this? Will this ultimately be a performance problem when the app is live?
Note: the script blocks are quite small bits of code - I've moved most of my significant javascript into their own .js files.
Mm, I thinks it's more of a personal style thing with modern browsers, but if nothing else, trying to contain all the script for a view in one block at the bottom of the page will make for easier debugging and your future self will thank you for it!
As a general rule of thumb I will only have script blocks in pages that need to use the document.ready or variables from my viewmodel. Otherwise, I would move all the functions into their own js file. It helps keep the views cleaner and the browser will load the page faster since it won't block loading the page when it hits as many script tags. Plus, it will make debugging easier since you can go straight to the js file instead of having to find the function within the HTML.