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

Re: [Dancer-users] Custom Session Handler issues
by David Precious 27 May '11

27 May '11

[resending to list, as I realised I sent it direct approximately one ohnosecond after clicking send] On Friday 27 May 2011 17:04:35 J. Bobby Lopez wrote: > I took a look at the code you have for the CGISession implementation, it > looks fairly straight forward. > > A couple of questions though: > > > 1. Does using Dancer::ModuleLoader->load('CGI::Session') mean that we > should have access to all objects and methods exported by CGI::Session? > For example, can I access CGI->self_url() somehow? The plugin loads CGI::Session, so anything that CGI::Session exports by default would be exported into the *plugin*'s namespace. (The plugin could skip using Dancer::ModuleLoader and just "use CGI::Session ();" directly, to avoid anything being exported). The plugin could provide a keyword like, say, cgi_session() that would give you direct access to the CGI::Session object, should you need to do things with it directly. I'm not sure why you'd want to use CGI.pm within a Dancer app, personally, nor would I be sure it would work appropriately either, especially if it expects to use STDIN and STDOUT. > 2. Would I be able to access Dancer settings and variables form a > sub-module? E.g.: Is there any way to access Dancer's 'cookies' or > 'session' info from a module, without having to pass them as arguments > to my module? Any module that imports Dancer syntax with "use Dancer qw(:syntax)" would be able to use them. Cheers Dave P -- David Precious ("bigpresh") http://www.preshweb.co.uk/ "Programming is like sex. One mistake and you have to support it for the rest of your life". (Michael Sinz)

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Custom Session Handler issues
by J. Bobby Lopez 27 May '11

27 May '11

Hi all, I've been trying to track down the root of a problem I'm having with Dancer, and a custom session handler that I am using. I've been told (several IRC discussions, and scouring the Dancer docs) that unless I specifically enable sessions within dancer (either simple or YAML), that no session handling code gets initialized by default in Dancer. However I'm finding that something is preventing my CGI::Session files from being written to disk, as they are in my other non-dancer applications using code similar to the following: http://pastebin.jbldata.com/m2571aaf0 This isn't the precise code I'm trying to use in my application, but has been simplified in order to provide the same results without a lot of noise. The code defines that the CGI::Session driver writes session files to '/tmp', however no session files are written there. Running this app, you can clearly see that the custom session handler is working when you run the application from the command line (e.g, 'perl dancer-sessiontest.pl'), and visit the application in a browser using the '/' or '/dump_session' routes. If these files are not written to the directory I've specified, then likely they are being stored in memory, but how and why is it doing that if Dancer does not do any session handling by default? As you can see, I'm using a very skeletal, single file Dancer application, which does not attempt to load any of Dancer's session handling modules. Can anyone explain what is happening here, and how to get my session files handled correctly? Thanks very much for any assistance, -Bobby

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Packaging Dancer to CPAN
by Pedro Melo 26 May '11

26 May '11

Hi, I need to repack a Dancer-based site as a CPAN module. I remember seeing a bit of documentation about this somewhere but I can't find it at the moment. Any pointers to documentation or an example on how to do this? Thanks in advance, -- Pedro Melo http://www.simplicidade.org/ xmpp:melo@simplicidade.org mailto:melo@simplicidade.org

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set layout for a single prefix
by Brian E. Lozier 26 May '11

26 May '11

I usually don't use the dancer layout mechanism. I use the template::toolkit WRAPPER stuff because it lets me define variables in templates and the wrapper template can see them. This allows me to set title tags in the content template and they get picked up by the outer template. I've started messing with Dancer::Plugin::SimpleCRUD and it's applying layouts manually (there's no real way for me to tell not to do that) and it doesn't use the template() function so I can't hook into it. I'm looking into working around that at least until I can make a patch or BIGPRESH can change that. In the meantime, I'm wondering if there's a way for me to set the layout for a single dancer module under "prefix." For example, I'll use my normal, non-layout modules: MyApp::Root (prefix undef) MyApp::Forums (prefix /forums) MyApp::Articles (prefix /articles) But then for some other module: MyApp::Admin (prefix /admin) I will use a layout. Is this possible? When I "set layout" in MyApp::Admin it uses the layout for the non-admin routes as well. Thanks, Brian

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separate sessions under the same base URL
by P Kishor 25 May '11

25 May '11

A while back I wrote an authentication module to use with Dancer. I called it accounts.pm in which I initialized the $dbh using a sessions_db declared in config.yml. Then, I inherited from accounts.pm in my Dancer app with `use base` and all was good. Well, now it turns out, I have another sub-app, and I want to use accounts for that as well, but how do I tell accounts to use a different sessions store? In other words, I want one set of auth for http://myapp.com/foo and another set of auth for http://myapp.com/bar. Because I am using SQLite, I have separate db for foo and bar, so I would like to store the sessions info for foo and bar in their respective db. Of course, someone with an account to access foo, but not for bar should not be able to get into bar, and vice versa. Ideas? -- Puneet Kishor

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URI design question
by Mr. Puneet Kishor 25 May '11

25 May '11

Not really a Dancer-question per se, but you all are really, really smart, hence... So, I've taken this whole REST thing to heart. My approach is that the web application itself is a client now, just like a command-line program might be a client, to the data store. So, when the web page loads, even the very first time, it is like an empty form. On load, an ajax query is fired to GET the records that are then filled in. Consider a simple books catalog (make believe app). 1. User goes to [http://myapp.com] 2. A web page loads. It has all the "chrome" (the logos, buttons, etc.), but no books. On load, a call is made to [http://myapp.com/books] which sends back a JSON object with all the books, and the web page comes alive. Except, the address bar in the browser still says [http://myapp.com] Ok. no matter. 3. The books are tagged. So, the user clicks on one of the tags, say "Thrillers," and an ajax query is fired to [http://myapp.com/books/tag/thrillers] Once again, the correct data are received and the web page is filled in with the results. Except, the address bar in the browser still says [http://myapp.com] You get the idea. Since all interaction is via ajax, the browser never refreshes completely. So, the user has no visual indication as to where (s)he is on the web site. Which also leads to a problem -- there is no way to send a link to anyone. In other words, is it possible to change the address in the browser without refreshing the browser? Any other thoughts on such an application design? Puneet.

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Dancer::layout has been deprecated
by Nick Knutov 23 May '11

23 May '11

I see message Dancer::layout has been deprecated since version 1.3050. use 'set layout => "value"' But why was it done? For example: get '/' => sub { # do something my $message = template 'message', $data, {layout=>''}; # sending email with $message or inserting parsed data to DB # do something else template 'index', $data; }; So, in the new way I should read current setting('layout'), save it, set up new layout and restore old layout after if the old-style layout setup will be deprecated. This is ugly! Is there any other ways to do it beautiful? May be it is better to do it optional and not to deprecate this feature? -- Best Regards, Nick Knutov http://knutov.com ICQ: 272873706 Voice: +7-904-84-23-130

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init on first run
by Nick Knutov 21 May '11

21 May '11

Hello all, what is the best way to do some initialization for some data on the only first run? Something like 'before sub', but it should run only on the first run of the script instance. Example of use: our $first; before sub { # if this is the first run of instance # $cache->{statuses} = ... # load some static data from DB # I can do # _load_cache() unless $first; # $first = 1; # but this is not beautiful } -- Best Regards, Nick Knutov http://knutov.com ICQ: 272873706 Voice: +7-904-84-23-130

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libdancer-perl in ubuntu ppa
by Иван Бессарабов 21 May '11

21 May '11

I prefer to install all libraries on production and even on development servers via debain package system. I've created the ppa https://launchpad.net/~bessarabov/+archive/star and placed there all perl modules that are needed by dancer. Now if you have clean ubuntu 10.04 install you only need to say: sudo apt-get install python-software-properties sudo add-apt-repository ppa:bessarabov/star sudo apt-get update sudo apt-get install libdancer-perl And after that you can run dancer apps =)

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Dancer::Plugin::DBIC, plackup, and database connections
by Brian E. Lozier 20 May '11

20 May '11

I have written my app so far only in a "development" environment. I've just added some time zone handling and I'm worried I've programmed it such that different users can stomp on eachother's time zone. First, here is how it works currently: Detect user's time zone using javascript during registration (using https://bitbucket.org/pellepim/jstimezonedetect/wiki/Home ) and store it in the database. Please note that I don't care the timezone is exactly right, I just want to show reasonable dates/times by default. I might let them explicitly choose a time zone at some point in the future but that's not really what this question is about. When a user logs in I pull the tz info from the database and put it in their session. In a "before" handler I pull a database handle (dbh) from Dancer::Plugin::DBIC and set the session time zone like this: my $dbh = schema->storage->dbh(); $dbh->do("SET SESSION TIME ZONE ?", {}, $tz) or die("..some error..."); I'm currently running my application with plackup and then I have a nginx in front of that. The nginx serves all the "public" files (images, css) and then proxies to the actual web app for everything else. The problem is that I don't fully understand (or know where to find information on) the way Dancer::Plugin::DBIC and thus DBIC itself connects to the database. I'm wondering if the connections are persistent at all or if a new connection is created on each and every request. I've got a lot of experience with mod_perl and I've used Apache::DBI which pools connections and ensures that a handle isn't shared by multiple requests at the same time. I want to avoid a case where one user sets the time zone on the database session and then another user overwrites it. This should not happen if the connections are created on each request (but that can cause performance issues and I need to figure a way to have persistent connections) and it should also not matter if the db handle is dealt with similar to Apache::DBI. Thanks for any insight, Brian

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