I have tried all the possibilities. Following are my response headers
HTTP/1.1 200 OK
Expires: Sun, 20 Dec 2015 03:53:42 GMT
Accept-Ranges: bytes
Cache-Control: public, max-age=604800
Last-Modified: Wed, 02 Dec 2015 15:49:21 GMT
Etag: W/"25571-15163623fb3"
Content-Type: image/png
Content-Length: 152945
Date: Sun, 13 Dec 2015 03:53:42 GMT
Connection: keep-alive
But still it's not returning 304 status. If I refresh command refresh in Firefox it's downloading that image again with 200 response code. I don't want that if user click command refresh it's should return 304 status. instead of downloading new file it should take it from browser cache.
Following is my nodejs code
var expireTime = 604800000;
app.all('/css*', function(req, res, next) {
res.header('Expires', new Date(Date.now() + expireTime).toUTCString());
next();
});
app.use('/css',express.static(conf.nodePath + 'css',{ maxAge: expireTime}));
Can anyone guide me how to enable perfect cache. Thanks in advance..
Related
I am using flutter http https://pub.dev/packages/http package to download a file from my own webserver.
Below is the download function:
download(String url, {String filename}) async {
var client = http.Client();
var request = new http.Request('GET', Uri.parse(url));
var response = client.send(request);
String dir = (await getApplicationDocumentsDirectory()).path;
List<List<int>> chunks = new List();
int downloaded = 0;
response.asStream().listen((http.StreamedResponse r) {
r.stream.listen((List<int> chunk) {
// Display percentage of completion
debugPrint('downloadPercentage: ${downloaded / r.contentLength * 100}');
chunks.add(chunk);
downloaded += chunk.length;
}, onDone: () async {
// Display percentage of completion
debugPrint('downloadPercentage: ${downloaded / r.contentLength * 100}');
// Save the file
File file = new File('$dir/$filename');
final Uint8List bytes = Uint8List(r.contentLength);
int offset = 0;
for (List<int> chunk in chunks) {
bytes.setRange(offset, offset + chunk.length, chunk);
offset += chunk.length;
}
await file.writeAsBytes(bytes);
return;
});
});
}
But StreamedResponse r is always null when I download the file from my webserver. I can download files from other web servers and it is not null.
For testing purpose, I used the link https://www.rarlab.com/rar/wrar590.exe
Therefore, I think the problem might be because of the settings on my webserver.
From WinRAR server
I/flutter (18386): IOStreamedResponse
I/flutter (18386): ResponseCode: 200
I/flutter (18386): {last-modified: Thu, 26 Mar 2020 10:03:25 GMT, date: Mon, 04 May 2020 11:47:34 GMT, accept-ranges: bytes, strict-transport-security: max-age=31536000;, content-length: 3007728, etag: "2de4f0-5a1bf18799540", content-type: application/octet-stream, server: Apache}
From my webserver:
I/flutter (29858): IOStreamedResponse
I/flutter (29858): ResponseCode: 200
I/flutter (29858): {connection: keep-alive, last-modified: Thu, 16 Apr 2020 20:22:20 GMT, set-cookie: __cfduid=d2789e7dce3f93d32c76e1d7874ffce1b1588599373; expires=Wed, 03-Jun-20 13:36:13 GMT; path=/; domain=.devoup.com; HttpOnly; SameSite=Lax, cf-request-id: 02817fd5a30000ddc752a1d200000001, transfer-encoding: chunked, date: Mon, 04 May 2020 13:36:13 GMT, access-control-allow-origin: *, vary: Accept-Encoding,User-Agent, content-encoding: gzip, cf-cache-status: DYNAMIC, content-type: application/zip, server: cloudflare, accept-ranges: bytes, cf-ray: 58e29c029952ddc7-SIN}
Sometimes the server doesn’t return contentLength . If that’s the case, then contentLength will be null.
If you have control of the server, like in your case, you can set the x-decompressed-content-length header with the file size before you send it. On the client side, you can retrieve contentLength like this:
final contentLength = double.parse(response.headers['x-decompressed-content-length']);
If you don't have control of the server, you can just show the number of bytes that are being downloaded, or if you know the file size in advance, you can use it to help calculate the % number of bytes downloaded.
Added SetEnv no-gzip 1 to .htaccess file in webserver and it returns content-length
I need to load page from this url: https://medalist-a805c.web.app/HeardSuggest_Medalist.html which actually loads a page from a express server. I'm able to use cors, the express middleware. But the problem is, even though i need to load this url: https://www.alwaysheard.com/embed/Medalist/brand/$2a$10$Z9ib22YZyRWWZz/Vlzju3u9eZCZM.a8oUYorNPsKGzLPKu6vM696K?uname=embed&orgin=https%3A%2F%2Fwww.alwaysheard.com eventually.
The weird problem i'm facing is it always returns the homepage rather than the url i am trying to get which is: https://www.alwaysheard.com/embed/Medalist/brand/$2a$10$Z9ib22YZyRWWZz/Vlzju3u9eZCZM.a8oUYorNPsKGzLPKu6vM696K?uname=embed&orgin=https%3A%2F%2Fwww.alwaysheard.com
Any help will be highly appreciated. Many Thanks.
This is for a expressjs server.
This is my frotend calling code:
$.ajax({
url: _url,
data: { uname: "embed", orgin: _origin },
// dataType: 'json',
crossDomain: true,
type: "GET",
mode: 'no-cors',
headers: {
'mode': 'no-cors',
// "X-TOKEN": 'xxxxx',
// 'x-Trigger': 'CORS',
// 'Access-Control-Allow-Headers': 'x-requested-with',
// "Access-Control-Allow-Origin": "*",
// 'Authorization': 'Bearer fadsfasf asdfasdf'
},
success: function (data) {
console.log("data: ", data);
$("body").html(data);
}
});
And in backend i'm using app.use(cors());
Your URL is first returning a 302 redirect to the home page and then the $.ajax() system (actually the XMLHttpRequest system underneath it) is following that redirect automatically.
You can see a discussion of that topic here:
How to prevent ajax requests to follow redirects using jQuery
In newer browsers, you can use the fetch() interface instead and it contains a redirect option that allows you to tell it not to follow redirects.
FYI, it's unclear what you're really trying to accomplish here. There is no "page" to retrieve from this URL. That returns a 302 status and a few headers, no page.
In case this isn't clear to you, your long url returns this response:
HTTP/1.1 302 Found
Date: Fri, 18 Oct 2019 17:04:05 GMT
Content-Type: text/plain; charset=utf-8
Content-Length: 23
Connection: keep-alive
Server: nginx/1.14.1
Access-Control-Allow-Origin: *
Set-Cookie: _csrf=j6JfsEb_JbmSJlvHDoyhgatS; Path=/
Set-Cookie: connect.sid=s%3A8C1PVNBcm5395dwmPJ4Xbl7BNASxPH4W.WFZ6uz3NklxaObnWvZaZXI%2BoH5VdM9dnOi2VCTw3J%2BI; Path=/; Expires=Mon, 15 Oct 2029 17:04:05 GMT; HttpOnly
Surrogate-Control: no-store
Cache-Control: no-store, no-cache, must-revalidate, proxy-revalidate
Pragma: no-cache
Expires: 0
Location: /
Vary: Accept
This content was retrieved with curl -l -v yourlongurl.
I have an Azure function written in NodeJS where I'm attempting to cause an HTTP Redirect with a 302. The documentation is very sparse on what are valid entries in the response. As a result I've created an object with what I feel should be the correct entries to generate the redirect, but all I get is an XML response. Even items like the status code are shown in the XML rather than changing the real status code.
What am I doing wrong?
My Code:
module.exports = function(context, req){
var url = "https://www.google.com";
context.res = {
status: 302,
headers: {
Location: url
}
}
context.done();
}
This is the response I'm getting in the browser:
HTTP/1.1 200 OK
Cache-Control: no-cache
Pragma: no-cache
Content-Length: 1164
Content-Type: application/xml; charset=utf-8
Expires: -1
Server: Microsoft-IIS/8.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Wed, 18 Jan 2017 00:54:20 GMT
Connection: close
<ArrayOfKeyValueOfstringanyType xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"><KeyValueOfstringanyType><Key>status</Key><Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:int">302</Value></KeyValueOfstringanyType><KeyValueOfstringanyType><Key>headers</Key><Value i:type="ArrayOfKeyValueOfstringanyType"><KeyValueOfstringanyType><Key>Location</Key><Value xmlns:d5p1="http://www.w3.org/2001/XMLSchema" i:type="d5p1:string">https://www.google.com</Value></KeyValueOfstringanyType></Value></KeyValueOfstringanyType></ArrayOfKeyValueOfstringanyType>
The problem is that you're not defining the "body" in the response. This can be set to null, but it must be set for Azure functions to interpret it properly.
e.g. Update your code to:
module.exports = function(context, req){
var url = "https://www.google.com";
context.res = {
status: 302,
headers: {
Location: url
},
body : {}
}
context.done();
}
You will then get the desired response:
HTTP/1.1 302 Found
Cache-Control: no-cache
Pragma: no-cache
Content-Length: 0
Expires: -1
Location: https://www.google.com
Server: Microsoft-IIS/8.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Wed, 18 Jan 2017 01:10:13 GMT
Connection: close
Edited 2/16/2017 - Using "null" for the body currently throws an error on Azure. As a result the answer was updated to use {} instead.
This is a bug with azure functions, see this content headers issue.
For now, a workaround is to remove any content related headers if the body of your response is null.
A simple server I'm working can serve images. When browsing to the image URL directly, Chrome offers to download the image, rather than just showing it in the browser. Why is that? Presumably it is something in the headers?
The relevant code is this:
tilestore.getTile(req.param("z"), req.param("x"), req.param("y"), function(err, tile) {
if (!err) {
res.send(tile);
} else {
res.send("Tile rendering error: " + err + "\n");
}
});
Do I need to add something to the headers? They are currently as follows:
HTTP/1.1 200 OK
Server: nginx/1.4.6 (Ubuntu)
Date: Mon, 01 Sep 2014 07:22:30 GMT
Content-Type: application/octet-stream
Content-Length: 37779
Connection: keep-alive
X-Powered-By: Express
ETag: W/"9393-1937584155"
Ok, it's easy. Just set the content-type:
if (!err) {
res.contentType('image/png');
res.send(tile);
} else {
res.send("Tile rendering error: " + err + "\n");
}
These images are always .png.
New headers:
HTTP/1.1 200 OK
Server: nginx/1.4.6 (Ubuntu)
Date: Mon, 01 Sep 2014 07:33:22 GMT
Content-Type: image/png
Content-Length: 37779
Connection: keep-alive
X-Powered-By: Express
ETag: W/"9393-1937584155"
Just ran into this same problem, and found that modifying the content type alone was not enough. This answer, attempting to do the opposite, provided the solution. I also needed to add a content-disposition header:
res.set("Content-Disposition", "inline;");
Along with setting the correct content type, this allowed me to display my image rather than downloading.
I had the same problem with svg image files and it turned out that I had to change
'content-type': 'image/svg'
to
'content-type': 'image/svg+xml'
My CouchDB show function will not run the provides('json', ...) function. It will run the html provides in certain cases though. Here is the show function:
function(doc, req) {
provides('json', function(){
return {'json': doc };
});
provides('html', function(){
return "<html><body>html string here</body></html>";
});
return {'json': {
'hello': "goodbye"
}
};
}
Here is a sample request when sending text/x-json. hello:goodbye is also returned if I use Accept: application/json
dave#ubuntu-laptop:~/py/liqc$ curl -i -H "Accept: text/x-json" http://127.0.0.1:8001/liqc/user-dave
HTTP/1.1 200 OK
Content-Length: 20
Vary: Accept
Server: CouchDB/1.0.2 (Erlang OTP/R14B)
ETag: "6V7EMSS64ZQ5SRLI0EYQVDWES"
Cache-Control: must-revalidate
Date: Mon, 27 Jan 2014 15:54:31 GMT
Content-Type: text/plain;charset=utf-8, text/x-json
{"hello":"goodbye"}
When I request text/html, I also get hello:goodbye. If I remove the final return of the show function however, application/json will continue to give me hello:goodbye, but text/html will give me the results I want!
dave#ubuntu-laptop:~/py/liqc$ curl -i -H "Accept: text/html" http://127.0.0.1:8001/liqc/user-dave
HTTP/1.1 200 OK
Content-Length: 42
Vary: Accept
Server: CouchDB/1.0.2 (Erlang OTP/R14B)
ETag: "9B8K3XGK28Y7RL2ART28WLL50"
Date: Mon, 27 Jan 2014 16:02:41 GMT
Content-Type: text/html; charset=utf-8
<html><body>html string here</body></html>
Am I doing something wrong or is this something going on with CouchDB? I am running a localhost reverse proxy to cloudant BTW. Thanks for any help.
You're not supposed to use a final return if you use provides. return supersedes any provides.
Plus, what do you expect to get when requesting JSON while your show function provides JSON in two different places? Use only provides and you will be fine.
About this:
If I remove the final return of the show function however, application/json will continue to give me hello:goodbye
There is no way you can get "hello":"goodbye" if you removed completely the final return. Maybe you forgot to update the design document? Debugging the wrong source code can be very frustrating…