What is the best way to handle style that that is user-customized? Just as an example of the result I'm looking for, this would suffice:
body {
color: {{ user.profile.text_color }};
}
However, serving CSS as a view seems like it would cause a significant amount of overhead in a file that is constantly requested, so this is probably not a good solution.
The user does not have access to the CSS files and we must assume that they have no web development knowledge.
However, serving CSS as a view seems like it would cause a significant amount of overhead in a file that is constantly requested, so this is probably not a good solution.
And what if you would generate that CSS once?
Default CSS is: /common/css.css
Member customize CSS, now <link /> elements points to /user-specific/123.css?ts=123123123. 123 is of course an identifier of the member, and ts parameter contains a timestamp - a date of last CSS modification
Make sure that your CSS generator sets proper HTTP headers responsible for client-side caching
User browser request a CSS file - server replies with simple 304 Not Modified header - there is no need for any script execution or contents download
When member modifies his CSS then you just update ts - once again just a single request is needed
Do the CSS dynamically via a view as normal, but use aggressive caching so that it loads quickly.
You can try django mediagenerato, actually I read this Q and I was searching for solution like you, then I found that Django-mediagenerator
I didn't tried it yet but it seams to be a solution.
Related
I noticed some websites put the version numbers (especially) in the CSS file path. For example:
<link rel="stylesheet" type="text/css" href="style.css?v=12345678" />
What is the main purpose to put the version number? If the purpose is to remember when the CSS file was updated last time, shouldn't the version number added as a comment inside the CSS file?
From HTML5 ★ Boilerplate Docs:
What is ?v=1" '?v=1' is the JavaScript/CSS Version Control with
Cachebusting
Why do you need to cache JavaScript CSS? Web page designs are getting
richer and richer, which means more scripts and stylesheets in the
page. A first-time visitor to your page may have to make several HTTP
requests, but by using the Expires header you make those components
cacheable. This avoids unnecessary HTTP requests on subsequent page
views. Expires headers are most often used with images, but they
should be used on all components including scripts, stylesheets etc.
How does HTML5 Boilerplate handle JavaScript CSS cache? HTML5
Boilerplate comes with server configuration files: .htacess,
web.config and nginx.conf. These files tell the server to add
JavaScript CSS cache control.
When do you need to use version control with cachebusting?
Traditionally, if you use a far future Expires header you have to
change the component's filename whenever the component changes.
How to use cachebusting? If you update your JavaScript or CSS, just
update the "?v=1" to "?v=2", "?v=3" ... This will trick the browser
think you are trying to load a new file, therefore, solve the cache
problem.
It's there to make sure that you have the current version. If you change your website and leave the name as before, browser may not notice the change and use old CSS from its cache. If you add version, the browser will download the new stylesheet.
If you set caches to expire far in the future adding ?v=2 will let the server know this is a new file but you won't need to give it a unique name (saving you a global search and replace)
HTM5 boilerplate also includes it in their project.
Check this video also: HTML5 Boilerplate Walkthrough.
One of the reason could be to bypass file caching. Same name CSS files can be cached by the servers and may result in bad display if new version has has layout changes.
This is to optimise browser-caching. You can set the header for CSS files to never expire so the browser will always get it from its cache.
But if you do this, you'll get problems when changing the CSS file because some browsers might not notice the change. By adding/changing the version-parameter it's "another" request and so it won't be taken from the cache (but after the new version is cached, it's taken from there in the future to save bandwidth/number of requests until the version changes again).
A detailed explanation can be found at html5boilerplate.com.
My knowledge is pretty much out of date regarding websites, but the variable stored in the 'href' argument is received by the browser through HTTP. Using the usual tricks in URL-rewriting you could actually have an arbitrary script that produces CSS-output when called. That output can differ, depending on the argument.
I have a dynamic PHP stylesheet, but I can't find a way to send variables to it so I used sessions instead. Figured this kinda sucked, so I'm going to give it another try but could need some help. It's an external stylesheet where a variable has effect through the whole document.
You probably want to use an embedded stylesheet (a <style> block) in the page: it increases the size of the main page, but solves the variable access issue without needing sessions and reduces your number of requests. You can just load your dynamic stylesheet into the main page's view using load->view.
EDIT: Ah, massive amounts of CSS would be one problem. Well, two alternatives are to:
Turn on the $_GET support in your CI install, you COULD pass in a request parameter in the CSS link and then check for the request parameter in the PHP controller or view file that generates the actual CSS. Not visually the tidiest option, but it does work.
Put in a cookie that you check in the controller that gets called for the CSS: you can then check that in the controller or view and do the right thing. Visually much tidier than the request parameter option, but a bit more involved.
Hey, anyone have any idea what the best way to allow users to save custom css would be? Specifically, there are about 4 color values that I would like to allow a user to choose and these colors would be used to create a custom theme for the user. I'm thinking save values in the database and then using dom:loaded with prototype to set the custom style values but I'm wondering if theres a faster way? Like dynamically creating css files or something?
and then using dom:loaded with prototype
Awww, don't do that! That won't work when JavaScript is turned off.
Approach 1: Static stylesheet, dynamic values in document head
For the sake of not having to work with a dynamically created style sheet, have a separate, static CSS file with all the definitions that won't change.
<link rel="stylesheet" href="styles/static.css" type="text/css">
<!-- Or whatever you name it -->
All the definitions that will change, you could put into the head of the HTML document, fetching the user-changeable values from a database.
<style type="text/css">
.classname { font-size: (fontsize); } <-- Insert dynamic value here
.classname { color: (color); } <-- Insert dynamic value here
....
<style>
that way, the majority of the CSS stays in static, cacheable files, while the dynamic part won't cause another HTTP request.
Approach 2: Dynamic stylesheet
If you have a lot of dynamically changing values, put the entire style sheet into a script file and output it, replacing placeholders with the values from the database.
The downside to this is that to force the browser to reload the style sheet on changes, you'll have to work with a version approach stylesheet.css?version=400 which is pretty complex to do, but can sometimes be more desirable than littering the head section with CSS.
You decide which approach suits your situation better. I find myself choosing the first one most often.
I would save the 4 values in the database and then create a css file from those values. You would want to make sure and cache the created css file for each user so you don't have to dynamically create it each page view.
Creating a custom css file adds another request the browser has to make so you would need to make sure your setting up the headers correctly to cache it. If the user does change their settings you would need do something to ensure the browser immediately stops cashing the old css file and loads the new file. One way to do this is to change the url of the css file.
Example:
/usercustom.css?version=(last saved date hash)
Instead I would use your first approach and create a JSON array that you inject into the page and then you use your javascript framework to load and use the array to style the page.
You could also store the color values in the cookie from the server and use and or write to them on the client.
I think that best way is to save it to Db, because you don't want to allow user to mess with your website. At least if some pages are public.
And I personally think that answers like "do it without JavaScript" is nothing but old school BS... Did they tried to turn of JavaScript today? I don't think so... And by this paragraph I don't mean that you have to do it using JavaScript. Do it in a way that suits your needs 🤔
Wish you nice Day
I found out that some websites use css tag like style.css?ver=1. What is this?
What is purpose of ?ver=1?
How do I do it in code?
To avoid caching of CSS.
If the website updates their CSS they update the ver to a higher number, therefore browser is forced to get a new file and not use cached previous version.
Otherwise a browser may get a new HTML code and old CSS and some elements of the website may look broken.
Adding '?ver=1' makes the HTTP request look like a GET query with parameters, and well-behaved browsers (and proxies) will refuse to cache parameterized queries. Of course well-behaved browsers (and proxies) should also pay attention to the 'Cache-control: no-cache', 'Expires', 'Last-Modified', and 'ETag' response headers (all of which were added to HTTP to specify correct caching behavior).
The '?ver=1' method is an expensive way to force behavior when the site developer doesn't know how (or is too lazy) to implement the correct response headers. In particular, it means that every page request is going to force requesting that CSS file, even though, in practice, CSS files change rarely, if at all.
My recommendation? Don't do it.
The purpose of the ?ver=1 is to parameterize the css file, so when they publish a new style.css file they up the version and it forces the client to download the new file, instead of pulling from the cached version.
If you are developing a web application in HTML and CSS or any other technology, and you are using some external CSS or JS files, you might notice one thing that in some cases if you made any changes to your existing .css or .js files then the browsers are not reflecting the changes immediately.
What happens in that case is that the browser do not download a fresh copy of the latest version of the .css and .js files, instead it uses those files stored in your local cache. As a result the changes you made recently are not visible to you.
<link rel="stylesheet" href="style.css?v=1.1">
The above case when you load the web page the browser will treat "style.css" as a different file along with "?v=1.1". Hence the browser is forced to download a fresh copy if the stylesheet or the script file.
I think that ?ver=1 is for the version no. of the web app. Every time a new build is created, the app can update the ver to the new version. This is so that the browser will load the new CSS file and not use the cached one (both use different file names).
You can refer to this site: http://www.knowlegezone.com/36/article/Technology/Software/JavaScript/CSS-Caching-Hack----javascript-as-well
IMO a better way to do this would be to include a hash generated off of the file size or a checksum based on the file contents or last-modified date. That way you don't have to update some version number and just let the number be driven off of the file's changing properties.
I have a legacy application that I needed to implement a configuration page for to change text colors, fonts, etc.
This applications output is also replicated with a PHP web application, where the fonts, colors, etc. are configured in a style sheet.
I've not worked with CSS previously.
Is there a programatic way to modify the CSS and save it without resorting to string parsing or regex?
The application is VB6, but I could write a .net tool that would do the css manipulation if that was the only way.
You don't need to edit the existing one. You could have a new one that overrides the other -- you include this one after the other in your HTML. That's what the "Cascading" means.
It looks like someone's already done a VB.NET CSS parser which is F/OSS, so you could probably adapt it to your needs if you're comfortable with the license.
http://vbcssparser.sourceforge.net/
One hack is to create a PHP script that all output is passed through, which then replaces certain parts of CSS with configurable alternatives. If you use .htaccess you can make all output go through the script.
the best way i can think of solving this problem is creating an application that will get some values ( through the URL query ) and generate the appropriate css output based on a css templates
Check this out, it uses ASP.NET and C#.
In my work with the IE control (shadocvw.dll), it has an interesting ability to let you easily manage the CSS of a page and show the effects of modified CSS on a page in realtime. I've never dealt with the details of such implementations myself, but I recommend that as a possible solution worth looking at. Seeing as pretty much everyone is on IE 6 or later nowadays, you can skip the explanations about handling those who only have IE 5,4,3 or 2 installed.
Maybe the problem's solution, which is most simple for the programmer and a user is to edit css via html form, maybe. I suppose, to create css-file, which would be "default" or "standart" for this application, and just to read it, for example, by perl script, edit in html and to write it down. Here is just the simple example.
In css-file we have string like:
border-color: #008a77;
we have to to read this string, split it up, and send to a file, which will write it down. Get something like this in Perl:
tr/ / /s;
($vari, $value) = split(/:/, _$);
# # While you read file, you can just at the time to put this into html form
echo($vari.":<input type = text name = ".$vari." value = ".$value.">");
And here it is, you've got just simple html-form-data, you just shoul overwrite your css-file with new data like this:
...
print $vari[i].": ".$value.";\n";
...
and voila - you've got programmatical way of changing css. Ofcourse, you have to make it more universal, and more close to your particular problem.
Depending on how technically oriented your CSS editors are going to be, you could do it very simply by loading the whole thing up into a TextEdit field to let them edit it - then write it back to the file.
Parsing and creating an interface for all the possibilities of CSS would be an astronomical pain. :-)