PROBLEM:
Today, we modified a static html web page in a client's website -
we added a couple of images and modified the font. And FTPed the file to client's web server.
We realized we made a mistake with the font-size, corrected it, and FTPed the file again.
Even with a 100 refreshes, the website was displaying only the file (with wrong font) that we had FTPed the first time.
We FTPed the corrected file several times, but the file with the wrong font was the only file being served by the web server.
OUR GUESS:
We think that the web server cached the file that we had FTPed the first time, and is serving it back to us on subsequent requests even though the file had changed.
We tried the following techniques (but were unsuccessful):
We added a parameter to the querystring (?R=33343545)
We tried the technique suggested below - i.e. posting to the webpage in question, but got a "405 Method not allowed. The HTTP verb used to access this page is not allowed."
http://www.mnot.net/blog/2006/02/18/invalidation
Please advise if we were on the right path and if there is anything else that we can try in such situations ?
EDIT:
We would like to find out if there is a way (similar to the 2 methods above) to do it just from the browser..and not touch the settings on the webserver.
Related
In one of the online documents that talks about appcache for HTML5, it indicates that the cached files get updated once an offline user reconnects. I checked the original HTML5 appcache definition by W3, and I am not able to find anything that supports this statement.
Does anyone know if this is to be true?
Thanks in advance
MDN says the following, although if you scroll up on that page it says it's being deprecated.
If an application cache exists, the browser loads the document and its associated resources directly from the cache, without accessing the network. This speeds up the document load time.
The browser then checks to see if the cache manifest has been updated on the server.
If the cache manifest has been updated, the browser downloads a new version of the manifest and the resources listed in the manifest. This is done in the background and does not affect performance significantly.
And logic tells me that it would also depend on the app you're using, server you're trying to connect to and any special settings it might have, how long your browser keeps it's history, what it keeps, and if you saved the page to view offline - whether or not you have all the code/images saved in the right location(s).
Example:
Imagine you saved a page to view offline, and that page has a JS event handler that ran a while loop that did an ajax request every n seconds to do something, like make a number on a page change as long as you were online... As long as the loop is running, you suddenly connect to the internet, and it makes the request to the proper url with the right arguments, then it should go through, even though the url in your browser might say something like file:///C:/Users/you/Desktop/....
I've done this before, even though my url was like the one above. One time I was using braintree's drop-in javascript to a website, and using it's api on my backend. Trying to load the page when offline = Nothing. Online = Updated the spot on the page just fine when I had the required arguments, and it was pointing to the right url. If I got offline again, I could refresh the page, see the same images loaded in the <div>, but I couldn't send any data with it.
I am trying to improve my site load speed. When checking on the network requests, there is something that doesn't make sense to me:
How can the content that is going to be requested (css and js files) is being download before the html content has been downloaded?
I have tried with a hard reload and empty cache from chrome, but this has happened again. Morover, the files seem to be dowload from the server and not from the cache.
Another thing I don't get, is why chrome is pating the bar chart almost all with blue, when the majority of the time is waiting for the server to respond (TTFB).
Thanks in advance!
There's a couple of possibilities:
The HTML doesn't download all at once. It's possible for the server to send part of the page, pause, then send the rest. If the part that's sent first contains references to CSS, JS, image, font, or other files, the browser can start downloading those files as soon as it sees them referenced.
HTTP 2.0 supports "server push", a scheme where the web server can indicate to the client through HTTP headers that it should start downloading specific other files. Judging from some of the file names in your network tab, you're using Cloudflare; they use server push for some features, including "Rocket Loader".
How do I find the filename of an website I am inspecting with Firebug? As example when I look on http://example.org/ I can view inspect the Element, I see the whole html structure but I didn`t find the filename. I am searching for index.html or something in that way. Maybe this is an analog question, but I am not sure, because he/she is working with php. LINK
I know there are some solutions with Dreamweaver or other tools but I am searching for an easy way to figure that out with Firebug or an free Browser Add-On. I Hope you have a solution for that.
The URL you entered is the one that usually returns the main HTML contents. Though on most pages nowadays the HTML is altered using JavaScript. Also, pages are very often dynamically generated on the server.
So, in most cases there is no static .html file.
For what it's worth, you can see all network requests and their responses within Firebug's Net panel.
Note that the URL path doesn't necessarily reflect a file path on the server's file system. It is depending on the server configuration, where a specific URL maps to in the file system. The simplest example is the index file that is automatically called when a domain is accessed. In the case of http://example.org the server automatically loads a file index.html in the file system, for example.
So, in order to get the file name on the file system, you need to either check the server configuration or the related access logs.
I just came across a website pagesource and saw this in the header:
<link href="../css/style.css?V1" rel="stylesheet" type="text/css" />
Could we actually pass GET data to css? I tried searching but found no results apart from using PHP. Could anyone help make meaning of the ?V1 after the .css
I know this forum is for asking programming problems, however I decided to ask this since I have found no results in my searches
First of all, no you can't pass GET parameters to CSS. Sorry. That would have been great though.
As for the example url. It can either be a CSS page generated by any web server (doesn't have to be PHP). In this case the server can serve different pages or versions of the same page which might explain the meaning of V1, Version 1. The server can also dynamically generate the page with a server-side template. This is an example from the Jade documentaion:
http://cssdeck.com/labs/learning-the-jade-templating-engine-syntax
It can also just be used as cache buster, for versioning purposes. Whenever you enter a url the browser will try to fetch it only if it doesn't already have a cached copy which is specific to that URL. If you have made a change in your content (in this instance the css file) and you want the browser to use it and not the cached version you can change the url and trick the browser to think it's a new resource that is not cached, so it'll fetch the new content from the server. V1 can then have a symantic meaning to the developer serving as a note (ie I've changed this file once...twice..etc) but not actually do anything but break the cache. This question addresses cache busting.
There are different concepts.
At first, it only is a link - it has a name, it might have an extension, but this is just a convention for humans, and nothing more than a resource identifier for the server. Once the browser requests it, it becomes a server request for a resource. The server then decides how to handle this request. It might be a simple file it just has to return, it might be a server side script, which has to be executed by a server side scripting interpreter, or basically anything else you can imagine.
Again, do not trick yourself in thinking "this is a CSS file", just because it has a css extension, or is called style.
Whatever runs at the server, and actually answers the request, will return something. And this something then is given a meaning. It might be CSS, it might be HTML, it might be JavaScript, or an image or just a binary download. To help the browser to understand what it is, the server returns a Content-Type header.
If no content type is given, the browser has to guess what it is. Or the nice web author gave a hint on what to expect as response - in this case he gave the hint of text/css. Again, this is how the returned content should be interpreted by the client/browser, not how that content is supposed to created on the server side.
And about the ?V1? This could mean different things. Maybe the user can configure a style (theme) for the website and this method is used to dispatch different styles. Or it can be used for something called "cache busting" (look it up).
You can pass whatever you want; the server decides what to do with the data.
After all, PHP isn't your only option for creating a server. If i wrote a server in Node.js, set up a route for /css/style.css and made it return different things depending on what query was given, neither the server nor browser will bat an eyelid.
Gurus of SO
I am trying to play with CACHE MANIFEST/HTML5. My app is JS heavy and built on jquery/jquerymobile.
This is an excerpt of what my Manifest looks like
CACHE MANIFEST
FALLBACK:
/
NETWORK:
*
CACHE:
/css/style.css
/js/jquery.js
But somehow, the app doesn't load the files the first time itself and the entire app breaks down.
Is my format wrong?
Should I never load JS into the Cache?
How should I treat this differently to always check the network first if anything isn't available and only load stuff available from the Cache?
Thank you.
I tried a simple page with your cache manifest and it worked fine for me, so I'm not really sure what the problem is. But,
Yes, there is something wrong with the format. The entries in the FALLBACK section need to have two parts: a pattern, and a URL. This says "if any page matching the pattern is not available offline, display the URL instead (which will be cached)." The main example of this (as shown here) is "/ /offline.html", which means "for all pages, if we are offline and they are not cached, display /offline.html instead." However, I don't think this is the source of your problem since I tested it with your exact manifest and it still worked.
There is nothing special about JS files. It should be fine to load them into the cache.
I don't understand the third question. There are possibly two goals here: a) how do you check to see if there is a newer version of the file available online first, before going back to the cache, and b) how do you check the network to see if there is a file that is not cached, and if we are offline, fall back to an error page. The answer to (a) is that once you have turned on the cache manifest, things work very differently. It will never check for new versions of the files unless there is a new version of the manifest also. So you must always update the manifest whenever you change any files. The answer to (b) is the FALLBACK section.
See Dive Into HTML5's excellent chapter on this, particularly the section "The fine art of debugging, a.k.a. “Kill me! Kill me now!”" which explains how the manifest updates.
Also I don't think we've gotten to the meat of your question, because it's unclear what you mean by "the app doesn't load the files the first time itself". Which files don't load? Do they load properly after a refresh? Etc.
The only way I got this to work to refresh a cache was to rename the manifest file with a commit number or timestamp, and change the cache declaration to
<html manifest='mymanifest382330.manifest'>
I made this part of my build.