Hi Bernhard,
Sorry, I'd to check my code instead of post it blindly. And yes this
looks as bug for me.
To fix this you have to return any value from list function like:
function(head, req) {
start({"code": 301, "headers": {"Location": "http://google.com"}});
return 'redirecting...';
}
this _any_ value may be also empty string, but not null. return ''; also fixes.
--
,,,^..^,,,
On Wed, Sep 18, 2013 at 5:04 PM, Bernhard Gschwantner
<[email protected]> wrote:
> Hi Alexander,
>
> Thanks a lot for the detailled answer! I completely understand what you're
> saying. I've been following the JIRA issues COUCHDB-430, COUCHDB-514 etc.
> for years, since this redirect topic was one of the first obstacles I ran
> into when starting to use CouchDB.
>
> Nevertheless I still don't get a valid redirect, even with start(). It's a
> bit embarrassing that I can't get a simple _list function right... ;-)
>
>
> I put this design doc into a new database "redirect":
>
>
> {
> "_id": "_design/redirect",
> "views": {
> "all": {
> "map": "function(doc) {\n\temit(doc._id, null);\n}"
> }
> },
> "lists": {
> "redirect": "function(head, req) {\n\tstart({\n\t\t\"code\":
> 302,\n\t\t\"headers\": {\n\t\t\t\"Location\": \"http://www.google.com
> \"\n\t\t}\n\t});\n}"
> }
> }
>
>
> The couchdb output when calling
> http://localhost:5984/redirect/_design/test/_list/redirect/all
>
> {"error":"unknown_error","reason":"undef"}
>
>
> This is the couchdb.log output (level INFO):
>
>
> [error] [<0.20382.0>] Uncaught error in HTTP request: {error,undef}
> [info] [<0.20382.0>] Stacktrace: [{undefined,write_chunk,[[]],[]},
> {couch_httpd,last_chunk,1,
> [{file,
>
> "/Users/jan/Work/build-couchdb-mac/build-couchdb/git-build/https%3A%2F%
> 2Fgit-wip-us.apache.org
> %2Frepos%2Fasf%2Fcouchdb.git%3A1.4.0/src/couchdb/couch_httpd.erl"},
> {line,692}]},
> {couch_mrview_show,list_cb,2,
> [{file,
>
> "/Users/jan/Work/build-couchdb-mac/build-couchdb/git-build/https%3A%2F%
> 2Fgit-wip-us.apache.org
> %2Frepos%2Fasf%2Fcouchdb.git%3A1.4.0/src/couch_mrview/src/couch_mrview_show.erl"},
> {line,254}]},
> {couch_mrview,finish_fold,2,
> [{file,
>
> "/Users/jan/Work/build-couchdb-mac/build-couchdb/git-build/https%3A%2F%
> 2Fgit-wip-us.apache.org
> %2Frepos%2Fasf%2Fcouchdb.git%3A1.4.0/src/couch_mrview/src/couch_mrview.erl"},
> {line,339}]},
> {couch_query_servers,with_ddoc_proc,2,
> [{file,
>
> "/Users/jan/Work/build-couchdb-mac/build-couchdb/git-build/https%3A%2F%
> 2Fgit-wip-us.apache.org
> %2Frepos%2Fasf%2Fcouchdb.git%3A1.4.0/src/couchdb/couch_query_servers.erl"},
> {line,269}]},
> {couch_httpd,etag_maybe,2,
> [{file,
>
> "/Users/jan/Work/build-couchdb-mac/build-couchdb/git-build/https%3A%2F%
> 2Fgit-wip-us.apache.org
> %2Frepos%2Fasf%2Fcouchdb.git%3A1.4.0/src/couchdb/couch_httpd.erl"},
> {line,600}]},
> {couch_httpd_db,do_db_req,2,
> [{file,
>
> "/Users/jan/Work/build-couchdb-mac/build-couchdb/git-build/https%3A%2F%
> 2Fgit-wip-us.apache.org
> %2Frepos%2Fasf%2Fcouchdb.git%3A1.4.0/src/couchdb/couch_httpd_db.erl"},
> {line,234}]},
> {couch_httpd,handle_request_int,5,
> [{file,
>
> "/Users/jan/Work/build-couchdb-mac/build-couchdb/git-build/https%3A%2F%
> 2Fgit-wip-us.apache.org
> %2Frepos%2Fasf%2Fcouchdb.git%3A1.4.0/src/couchdb/couch_httpd.erl"},
> {line,332}]}]
> [info] [<0.20382.0>] 127.0.0.1 - - GET
> /redirect/_design/redirect/_list/redirect/all 500
> [error] [<0.20382.0>] httpd 500 error response:
> {"error":"unknown_error","reason":"undef"}
>
>
>
> Is this a bug, or am I still missing something?
>
> Regards,
> Bernhard
>
>
>
> 2013/9/18 Alexander Shorin <[email protected]>
>
>> Hi Bernhard,
>>
>> you need to send redirect with start() function call.
>>
>> function(head, req) {
>> start({"code": 301, "headers": {"Location": "http://google.com"}});
>> }
>>
>> http://docs.couchdb.org/en/1.4.x/query-servers.html
>>
>> Why so? start() function allows to send custom HTTP headers to the
>> client before any response (or with first chunk of it). When you
>> return or send() something before or without start() call, query
>> server implicitly called it with empty object payload which means that
>> CouchDB will send default HTTP status code and headers. Since CouchDB
>> sends response of list functions as chunked transfer, it doesn't
>> buffers all of it to let you change HTTP response status or headers
>> somewhere in the middle - what's why you need to define them in first
>> place and start() function explicitly points on this.
>>
>> For show functions your code will work since they produces only one
>> response object which contains response body and optionally may have
>> HTTP status and headers. With a little adaptation, the same is true
>> for update functions too.
>>
>> --
>> ,,,^..^,,,
>>
>>
>> On Tue, Sep 17, 2013 at 5:34 PM, Bernhard Gschwantner
>> <[email protected]> wrote:
>> > Hello,
>> >
>> > I tried to redirect from a _list function without success. This code
>> throws
>> > a badarg error in CouchDB 1.4.0 (also in 1.2 and 1.3):
>> >
>> > function(head, req) {
>> > return {
>> > code : 301,
>> > headers : {
>> > Location : 'http://www.google.com'
>> > }
>> > };
>> > }
>> >
>> > Is there something I am doing wrong or missing?
>> >
>> > The real-world use case is that we have several aliases to each document
>> in
>> > the db, and all those aliases should be redirected to the real document
>> id.
>> > We use a view to emit the aliases and a list function to redirect all
>> those
>> > aliases to the real url.
>> >
>> > We've been working around the previous issues with modifying headers
>> after
>> > getRow() by redirecting through JavaScript, but want to get rid of this
>> > workaround eventually.
>> >
>> > Regards,
>> > Bernhard
>> >
>> > --
>> >
>> > Bernhard Gschwantner
>> > Unser Wein G&U OG
>> > Kirchengasse 13/7, 1070 Wien
>> >
>> > mobil: +43 (6991) 971 32 96
>> > tel: +43 (1) 971 32 95
>> > e-mail: [email protected]
>> > twitter: @bernharduw <http://twitter.com/bernharduw>
>> > web: www.unserwein.at
>>
>
>
>
> --
>
> Bernhard Gschwantner
> Unser Wein G&U OG
> Kirchengasse 13/7, 1070 Wien
>
> mobil: +43 (6991) 971 32 96
> tel: +43 (1) 971 32 95
> e-mail: [email protected]
> twitter: @bernharduw <http://twitter.com/bernharduw>
> web: www.unserwein.at
