July 2011 - dancer-users - lists.preshweb.co.uk

mysterious behavior putting Dancer app in production on Starman
by Mr. Puneet Kishor 17 Jul '11

17 Jul '11

Check out the following [http://teststrata.geology.wisc.edu/macromap] It should be working -- it should show a Google map backdrop with a bunch of polygons and a few points. As you pan and zoom, polys and points for the new viewport should be retrieved. The polys and points are retrieved via ajax from [http://teststrata.geology.wisc.edu/mstrat/] that is serving them from a MySQL db as a REST service. Both apps are Dancer based, and are running on Starman using the following invocation $ plackup -p <port> -E production -s Starman -w 10 -a bin/app.pl The first app (macromap) also has the -D switch added to the above plackup command so plackup runs in the background as a daemon (or a faceless app, or whatever is the correct terminology). Here is the interesting thing -- if I add the -D switch to the second app as well, it fails to return the polys and the points. It fails with the error {"error":"Warning caught during route execution: DBD::mysql::st fetchall_arrayref failed: fetch() without execute() at <path/to>/macrostrat.pm line 79.\n"} The offending lines are 71> my $sql = qq{ 72> .. 73> 74> 75> }; 76> 77> my $sth = $dbh->prepare($sql); 78> $sth->execute(); 79> my $res = $sth->fetchall_arrayref({}); The above could be just correlation rather than causal, but it definitely seems to be a pattern. First, this is bizarre, and why so? And, two... this is totally bogus... how can execute() not take place above? Perl doesn't have a habit of jumping over lines, does it? Absolutely mystified in Madison. Puneet.

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testing ajax
by Stephen Fenwick-Paul 17 Jul '11

17 Jul '11

Hi How to you approach testing ajax calls? If I had: use Dancer::Plugin::Ajax; ajax '/somedata.json' => sub { return { data => "hello" }; }; The tests: route_exists [ 'GET' => '/somedata.json'], 'a route handler is defined for /somedata'; response_status_is ['GET' => '/somedata.json'], 200, 'response status is 200 for /somedata'; give: 1..2 ok 1 not ok 2 - response status is 200 for / # Failed test 'response status is 200 for /' # at t/003_api_route.t line 10. # got: '404' # expected: '200' # Looks like you failed 1 test of 2. So how do I construct the response_status_is to be: X-Requested-With: XMLHttpRequest And secondly the route_exists call would also match: get '/somedata.json' => sub { return { data => "hello" }; }; so how do I distinguish between a GET and an AJAX call with a route_exists? Thanks for any pointers.

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New plugin
by Oleg A. Mamontov 15 Jul '11

15 Jul '11

Hi. I have recently uploaded the new Dancer plugin for common task of images thumbnails creation: http://search.cpan.org/~lonerr/Dancer-Plugin-Thumbnail It's probably offtopic for this list, but i hope to get some constructive criticism or new ideas from experienced Dancer developers. I would appreciate any comments! -- Cheers, Oleg A. Mamontov mailto: oleg(a)mamontov.net jabber: lonerr(a)charla.mamontov.net icq uin: 79-521-617 cell: +7-903-798-1352

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Re: [Dancer-users] cross domain ajax to dancer app
by Alex Kalderimis 13 Jul '11

13 Jul '11

That is exactly right. In this context the server is the whole stack, including your webapp, which is solely responsible for getting the content right. Dancer makes writing webapps easier, but it doesn't do everything. Perhaps this is a good area for a plugin or some sugar though... Alex ----- sent from my phone - please excuse any brevity ----- Reply message ----- From: "Mr. Puneet Kishor" <punk.kish(a)gmail.com> To: "Mr. Puneet Kishor" <punk.kish(a)gmail.com> Cc: "Alex Kalderimis" <alex(a)flymine.org>, "Dancer Users" <dancer-users(a)perldancer.org> Subject: [Dancer-users] cross domain ajax to dancer app Date: Wed, Jul 13, 2011 4:43 am On Jul 12, 2011, at 10:13 PM, "Mr. Puneet Kishor" <punk.kish(a)gmail.com> wrote: > On Jul 12, 2011, at 4:50 PM, "Alex Kalderimis" <alex(a)flymine.org> wrote: > >> Remember that jsonp requests must return their data wrapped in the function callback to work. If not, the json will be evaluated, but do nothing, as it is in void context (so to speak). Dancer does not do this for you - you will need to read the callback parameter yourself. On more research, I think I understand better what you are suggesting. I don't have access to my server ritnow, but I am guessing I would have to do something like follows >> get '/poly.:format' => sub { >> my $poly = params->{'BBOX'}; get '/poly.:format' => sub { my $poly = params->{'BBOX'}; + my $callback = params->{'callback'}; my $res = recs_within_poly($poly); + $res = $callback . '(' . $res . ')'; return $res; } Does the above make sense? >> > > > I kind of follow what you are saying, but I am not sure what I am supposed to do. From my side (the client side), I am specifying that it is a JSONP request, and I am even specifying the callback param. From what I understand, as you state above, the server is supposed to send back the JSON stream wrapped in the function callback. Let me read that again -- the server is supposed to do the above. Dancer is the responding server, and it is not doing so, as you confirm above. So, how do I read the callback param myself? > > I checked Firebug as well as the Safari web developer... The JSON object is clealy returned, but the jQuery Ajax call's success method is never triggered. Instead, its error method is triggered. > > Suggestions? > > Many thanks in advance. > > >> Alex. >> >> ----- >> sent from my phone - please excuse any brevity >> >> ----- Reply message ----- >> From: "Mr. Puneet Kishor" <punk.kish(a)gmail.com> >> To: "dancer-users" <dancer-users(a)perldancer.org> >> Subject: [Dancer-users] cross domain ajax to dancer app >> Date: Tue, Jul 12, 2011 10:30 pm >> >> >> I am trying to send an ajax GET request from one dancer app (powered by Starman on one port) to another dancer app (powered by Starman on another port). I am using jQuery like so >> >> $.ajax({ >> "url": url, >> "data": data, >> "type": "GET", >> "dataType": "jsonp", >> "jsonpCallback": function(res) { >> .. do something with res .. >> } >> }); >> >> I can see the result come back from the second dancer app in Safari web inspector. It looks like a JSON stream, but it doesn't trigger the jsonpCallback. The web inspector complains that "Resource interpreted as script but transferred with MIME type application/json." I am wondering if there is something in the second dancer app (the one that returns the result) which is setting a wrong header that is causing the callback to not be tripped. The code in the second dancer app looks like so >> >> use Dancer::Plugin::REST; >> prepare_serializer_for_format; >> >> use DBI; >> >> >> get '/poly.:format' => sub { >> my $poly = params->{'BBOX'}; >> >> my $res = recs_within_poly($poly); >> return $res; >> }; >> >> By the way, seems like if I use Dancer::Plugin::REST, I can't use Dancer::Plugin::Ajax, or can I? Changing the above route to `ajax '../ => sub {};` gives an error that the route was not found. >> >> >> _______________________________________________ >> Dancer-users mailing list >> Dancer-users(a)perldancer.org >> http://www.backup-manager.org/cgi-bin/listinfo/dancer-users

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Re: [Dancer-users] cross domain ajax to dancer app
by Alex Kalderimis 13 Jul '11

13 Jul '11

Remember that jsonp requests must return their data wrapped in the function callback to work. If not, the json will be evaluated, but do nothing, as it is in void context (so to speak). Dancer does not do this for you - you will need to read the callback parameter yourself. Alex. ----- sent from my phone - please excuse any brevity ----- Reply message ----- From: "Mr. Puneet Kishor" <punk.kish(a)gmail.com> To: "dancer-users" <dancer-users(a)perldancer.org> Subject: [Dancer-users] cross domain ajax to dancer app Date: Tue, Jul 12, 2011 10:30 pm I am trying to send an ajax GET request from one dancer app (powered by Starman on one port) to another dancer app (powered by Starman on another port). I am using jQuery like so $.ajax({ "url": url, "data": data, "type": "GET", "dataType": "jsonp", "jsonpCallback": function(res) { .. do something with res .. } }); I can see the result come back from the second dancer app in Safari web inspector. It looks like a JSON stream, but it doesn't trigger the jsonpCallback. The web inspector complains that "Resource interpreted as script but transferred with MIME type application/json." I am wondering if there is something in the second dancer app (the one that returns the result) which is setting a wrong header that is causing the callback to not be tripped. The code in the second dancer app looks like so use Dancer::Plugin::REST; prepare_serializer_for_format; use DBI; get '/poly.:format' => sub { my $poly = params->{'BBOX'}; my $res = recs_within_poly($poly); return $res; }; By the way, seems like if I use Dancer::Plugin::REST, I can't use Dancer::Plugin::Ajax, or can I? Changing the above route to `ajax '../ => sub {};` gives an error that the route was not found. _______________________________________________ Dancer-users mailing list Dancer-users(a)perldancer.org http://www.backup-manager.org/cgi-bin/listinfo/dancer-users

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cross domain ajax to dancer app
by Mr. Puneet Kishor 12 Jul '11

12 Jul '11

I am trying to send an ajax GET request from one dancer app (powered by Starman on one port) to another dancer app (powered by Starman on another port). I am using jQuery like so $.ajax({ "url": url, "data": data, "type": "GET", "dataType": "jsonp", "jsonpCallback": function(res) { .. do something with res .. } }); I can see the result come back from the second dancer app in Safari web inspector. It looks like a JSON stream, but it doesn't trigger the jsonpCallback. The web inspector complains that "Resource interpreted as script but transferred with MIME type application/json." I am wondering if there is something in the second dancer app (the one that returns the result) which is setting a wrong header that is causing the callback to not be tripped. The code in the second dancer app looks like so use Dancer::Plugin::REST; prepare_serializer_for_format; use DBI; get '/poly.:format' => sub { my $poly = params->{'BBOX'}; my $res = recs_within_poly($poly); return $res; }; By the way, seems like if I use Dancer::Plugin::REST, I can't use Dancer::Plugin::Ajax, or can I? Changing the above route to `ajax '../ => sub {};` gives an error that the route was not found.

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solving starman error with dancer's .psgi file
by Mr. Puneet Kishor 10 Jul '11

10 Jul '11

In httpd.conf ProxyPass /foo http://127.0.0.1:5001 ProxyPassReverse /foo http://127.0.0.1:5001 and foo.psgi file like so use Dancer ':syntax'; use Plack::Builder; setting apphandler => 'PSGI'; my $app = sub { my $env = shift; local $ENV{DANCER_APPDIR} = "/Users/punkish/Documents/www/foo"; setting appdir => "/Users/punkish/Documents/www/foo"; load_app "foo"; Dancer::App->set_running_app("foo"); Dancer::Config->load; my $request = Dancer::Request->new( env => $env ); Dancer->dance( $request ); }; builder { enable "Static", path => sub { s!^/lib/!! }, root => "/Users/punkish/Sites/lib"; mount "/" => builder {$app}; }; I start the above with $plackup -E development -s Starman --workers=10 -p 5000 -a foo.psgi The above works fine if I go to http://localhost.local/foo/, but if I go to http://localhost.local/foo (no trailing slash), all the resources at /lib are unreachable. But, here is a more confounding problem; to access the above as an apache virtual host, I change httpd.conf to <VirtualHost foo.local:80> ProxyPass / http://127.0.0.1:5001/ ProxyPassReverse / http://127.0.0.1:5001/ </VirtualHost> and change only the following line in foo.psgi to - mount "/" => builder {$app}; + mount "http://foo.local" => builder {$app}; But, now I get the following error Error while loading foo.psgi: Paths need to start with / at /Users/punkish/perl5/perlbrew/perls/perl-5.14.1/lib/site_perl/5.14.1/Plack/Builder.pm line 89

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The Perl password safe Challenge
by Gabor Szabo 09 Jul '11

09 Jul '11

hi, I have started a challenge to build a small application either web based or wxPerl based to provide a "password safe". http://szabgab.com/blog/2011/07/the-perl-password-safe-challenge.html It would be great to see at least one Dancer based solution! You have one week. enjoy! Gabor

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Is it possible to choose the Backend server via config.yml
by Gurunandan Bhat 09 Jul '11

09 Jul '11

Hi, I would like to share my application as PAR and a executable so that the backend server (say, Starlet) is chosen from a configuration settings rather than chosen on the command line (plackup -s Starlet ./app.pl). Is this possible? Thank you.

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Profiling Dancer app with Devel::NYTProf
by Gurunandan Bhat 09 Jul '11

09 Jul '11

Hi, D::NYTProf requires that the profiled application exit cleanly. Dancer::dance does not return and the only way to exit a dancer app (to my limited knowledge) is to either hit Ctrl-C or kill -HUP if running with -d. How can I exit a Dancer app cleanly so that NYTProf can write its profile Thanks!

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