I'm trying to make a single page website with sinatra in the backend. I want all GET-requests with preferred accept-header "text/html" to return the same page, BUT all requests that wants json to get json-data.
Example:
A GET call to '/users' with accept set to 'text/html' should return index.html.
A GET call to '/users' with accept set to 'application/json' should return the JSON-data with users.
I have tried using a catch-all method for html and using accept-checks like this:
# Generic html giver for angular routing
get //, :provides => 'html' do
pass unless request.preferred_type.to_str == 'text/html'
erb :index
end
# Give users as JSON
get '/users', :provides => 'json' do
pass unless request.preferred_type.to_str == 'application/json'
'["dummy", "array"]'
end
...but it doesn't seem to pass to the second route when preferred_type isn't text/html.
Note: I'm useing the string check on preferred_type, since using request.accept? catches all with browsers giving "*/*" as last accept header.
Oh, it seems like the culprit is:
:provides => 'json'
Without it, the passing works as expected. I guess it's a bug then.
Related
I'm creating a json web service using Mojolicious Lite.
By default Mojolicious returns a HTML response for a server error or not found error.
Is there a way to overwrite this to a custom JSON response?
Here are two approaches:
Use json as the app's default format and use a not_found.*.json.ep template
use Mojolicious::Lite;
app->renderer->default_format('json');
app->start;
__DATA__
## not_found.development.json.ep
{"not":"found","code":404,"data":{"key1":"value1","key2":[42,19,"value3"]}}
Override json payload with a before_render hook.
use Mojolicious::Lite;
hook before_render => sub {
my ($c,$args) = #_;
if ($args->{template} && $args->{template} eq 'not_found') {
$args->{json} = { "too bad" => "so sad" };
}
};
app->start;
It's been a minute, but in Mojo 9 in a full app I've just been returning JSON and returning the status:
$c->render( json => $json, status => 404 );
But, I also have a catch-all route at the end of my setup:
$self->routes->any('/*')->to( ... );
Note, however, that there are some decisions to make about HTTP codes and application-level messaging. For example, accessing a defined and valid endpoint that returns zero search results could easily return 200 and an empty JSON array. The endpoint was there, the server knew how to handle it, and zero list items can be seen as valid as any other number. See I've been abusing HTTP Status Codes in my APIs for years, for example.
The Rendering guide discusses how to customize these responses.
I am very new to Perl framework Dancer. As of now I have a get http listener working. I have an Angular framework trying to post a json string to Dancer. How can I retreive the json and perhaps assign it to a scalar variable ($json).
get '/games' => sub {
header 'Access-Control-Allow-Origin' => '*';
&loadgames();
return $games;
};
post '/newgame' => sub {
header 'Access-Control-Allow-Origin' => '*';
#what should i put here to retrieve the json string
#I plan to pass the json string to a sub to convert to XML
};
I am not sure If I chose Dancer as backend framework that will get and post data.
Thanks for the help!
If your HTTP request has a JSON body (Content-type: application/json) rather than being an HTML form post, then you probably want something like this:
post '/url-path' => {
my $post = from_json( request->body );
# do something with the POSTed data structure
# which would typically be a hashref (or an arrayref)
# e.g.: schema->resultset('Widget')->create($post);
}
The from_json routine is one of the DSL Keywords provided by Dancer.
Dancer provides the params keyword for accessing route, body, and query parameters. You want a body parameter. Exactly which body parameter you want will depend on the name of the field you posted it to the route with (look at your form or your ajax request).
my $json_string = params('body')->{$field_name}
You can also use param, if you don't have any conflicting parameter names in the route or query parameters.
Once you have the json, remember it's just a string at the moment. You might want to read it into a perl data structure: Dancer provides from_json for this purpose.
As an aside: I notice in your get route, you call a function loadgames in void context, and then return a variable you haven't declared (or perhaps you have set it as a global - but do you need it to be a global?). I recommend beginning each perl file with use strict; to pick up issues like this. I suspect you probably just want to use the return value of loadgames as your return value.
Working on building an API and would like to use RESTful routes.
I got it to work just fine like this:
http://www.mysite.com/events.json // returns json results with my events
http://www.mysite.com/events/123.json // returns json results with event of id '123'
BUT - I want to be able to do this using an 'api' prefix.
So, I added the api Routing prefix:
Configure::write('Routing.prefixes', array('admin', 'api'));
And changed my actions from 'view' and 'index' to 'api_view' and 'api_index'.
But now it doesn't work. (eg. I have to write the action name or it won't find the correct one based on HTTP.
The end goal would be to be able to do something like this:
GET http://www.mysite.com/api/1.0/events.json // loads events/api_index()
GET http://www.mysite.com/api/1.0/events/123.json // loads events/api_view($id)
DELETE http://www.mysite.com/api/1.0/events/123.json // loads events/api_delete($id)
...etc
I ended up having to just write the routes manually:
Router::parseExtensions('json', 'xml');
Router::connect('/api/:version/:controller/:id/*',
array('[method]'=>'GET', 'prefix'=>'api', 'action'=>'view'),
array('version'=>'[0-9]+\.[0-9]+', 'id'=>'[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}'));
Router::connect('/api/:version/:controller/*',
array('[method]'=>'GET', 'prefix'=>'api', 'action'=>'index'),
array('version'=>'[0-9]+\.[0-9]+'));
Router::connect('/api/*', array('controller'=>'events', 'action'=>'index', 'ext'=>'html'));
Notes:
The [method] is what forces the HTTP type (eg. RESTful)
The parseExtensions() makes it so you can have it display the data in different formats automatically by changing the extension in your URL.
The last Router:: line was just a catchall for anything /api/ that didn't match - it forwarded it to the homepage. Eventually I'll probably just route this to an API error page.
The 'ext'=>'html' of the last Router:: line was to keep parseExtensions from trying to use whatever extension was in the URL - if it's redirecting for reasons they made the call wrong, I just want it to go back to the homepage (or whatever) and use the normal view.
Try something like this.
Router::connect('/:api/:apiVersion/:controller/:action/*',
array(),
array(
'api' => 'api',
'apiVersion' => '1.0|1.1|'
)
);
With prefix routing
Router::connect('/:prefix/:apiVersion/:controller/:action/*',
array(),
array(
'prefix' => 'api',
'apiVersion' => '1.0|1.1|'
)
);
Will match only valid API versions like 1.0 and 1.1 here. If you want something else use a regex there.
I know this is an old post, but there is a routing method called mapResources which creates the special method based routing for you.
http://book.cakephp.org/2.0/en/development/rest.html
You put it in routes.php like so:
Router::mapResources(array('controller1', 'controller2'));
The docs have a nice little table showing how the requests are mapped to different actions, which you can always override if you need to.
I've built a REST Server and now I want to rapidly test it from a Perl Client, using REST::Client module.
It works fine if I perform GET Request (explicitly setting parameters in the URL) but I can't figure out how to set those params in POST Requests.
This is how my code looks like:
#!/usr/bin/perl
use strict;
use warnings;
use REST::Client;
my $client = REST::Client->new();
my $request_url = 'http://myHost:6633/my_operation';
$client->POST($request_url);
print $client->responseContent();
I've tried with something similar to:
$client->addHeader ('my_param' , 'my value');
But it's clearly wrong since I don't want to set an HTTP predefined Header but a request parameter.
Thank you!
It quite straight forward. However, you need to know what kind of content the server expects. That will typically either be XML or JSON.
F.ex. this works with a server that can understand the JSON in the second parameter, if you tell it what it is in the header in the third parameter.
$client->POST('http://localhost:3000/user/0/', '{ "name": "phluks" }', { "Content-type" => 'application/json'});
The REST module accepts a body content parameter, but I found to make it work with a string of parameters, you need to set a proper content type.
So the following code works for me:
$params = $client->buildQuery([username => $args{username},
password => $args{password}]);
$ret = $client->POST('api/rest/0.001/login', substr($params, 1),
{'Content-type' => 'application/x-www-form-urlencoded'});
I've not used the REST module, but looking at the POST function, it accepts a body content parameter, try creating a string of the parameters and send that within the function
$client->POST($request_url, "my_param=my+value");
print $client->responseContent();
I am very new to Perl and i am learning on the fly while i try to automate some projects for work. So far its has been a lot of fun.
I am working on generating a report for a customer. I can get this report from a web page i can access.
First i will need to fill a form with my user name, password and choose a server from a drop down list, and log in.
Second i need to click a link for the report section.
Third a need to fill a form to create the report.
Here is what i wrote so far:
my $mech = WWW::Mechanize->new();
my $url = 'http://X.X.X.X/Console/login/login.aspx';
$mech->get( $url );
$mech->submit_form(
form_number => 1,
fields =>{
'ctl00$ctl00$cphVeriCentre$cphLogin$txtUser' => 'someone',
'ctl00$ctl00$cphVeriCentre$cphLogin$txtPW' => '12345',
'ctl00$ctl00$cphVeriCentre$cphLogin$ddlServers' => 'Live',
button => 'Sign-In'
},
);
die unless ($mech->success);
$mech->dump_forms();
I dont understand why, but, after this i look at the what dump outputs and i see the code for the first login page, while i belive i should have reached the next page after my successful login.
Could there be something with a cookie that can effect me and the login attempt?
Anythings else i am doing wrong?
Appreciate you help,
Yaniv
This is several months after the fact, but I resolved the same issue based on a similar questions I asked. See Is it possible to automate postback from the client side? for more info.
I used Python's Mechanize instead or Perl, but the same principle applies.
Summarizing my earlier response:
ASP.NET pages need a hidden parameter called __EVENTTARGET in the form, which won't exist when you use mechanize normally.
When visited by a normal user, there is a __doPostBack('foo') function on these pages that gives the relevant value to __EVENTTARGET via a javascript onclick event on each of the links, but since mechanize doesn't use javascript you'll need to set these values yourself.
The python solution is below, but it shouldn't be too tough to adapt it to perl.
def add_event_target(form, target):
#Creates a new __EVENTTARGET control and adds the value specified
#.NET doesn't generate this in mechanize for some reason -- suspect maybe is
#normally generated by javascript or some useragent thing?
form.new_control('hidden','__EVENTTARGET',attrs = dict(name='__EVENTTARGET'))
form.set_all_readonly(False)
form["__EVENTTARGET"] = target
You can only mechanize stuff that you know. Before you write any more code, I suggest you use a tool like Firebug and inspect what is happening in your browser when you do this manually.
Of course there might be cookies that are used. Or maybe your forgot a hidden form parameter? Only you can tell.
EDIT:
WWW::Mechanize should take care of cookies without any further intervention.
You should always check whether the methods you called were successful. Does the first get() work?
It might be useful to take a look at the server logs to see what is actually requested and what HTTP status code is sent as a response.
If you are on Windows, use Fiddler to see what data is being sent when you perform this process manually, and then use Fiddler to compare it to the data captured when performed by your script.
In my experience, a web debugging proxy like Fiddler is more useful than Firebug when inspecting form posts.
I have found it very helpful to use Wireshark utility when writing web automation with WWW::Mechanize. It will help you in few ways:
Enable you realize whether your HTTP request was successful or not.
See the reason of failure on HTTP level.
Trace the exact data which you pass to the server and see what you receive back.
Just set an HTTP filter for the network traffic and start your Perl script.
The very short gist of aspx pages it that they hold all of the local session information within a couple of variables prefixed by "__" in the general aspxform. Usually this is a top level form and all form elements will be part of it, but I guess that can vary by implementation.
For the particular implementation I was dealing with I needed to worry about 2 of these state variables, specifically:
__VIEWSTATE
__EVENTVALIDATION.
Your goal is to make sure that these variables are submitted into the form you are submitting, since they might be part of that main form aspxform that I mentioned above, and you are probably submitting a different form than that.
When a browser loads up an aspx page a piece of javascript passes this session information along within the asp server/client interaction, but of course we don't have that luxury with perl mechanize, so you will need to manually post these yourself by adding the elements to the current form using mechanize.
In the case that I just solved I basically did this:
my $browser = WWW::Mechanize->new( );
# fetch the login page to get the initial session variables
my $login_page = 'http://www.example.com/login.aspx';
$response = $browser->get( $login_page);
# very short way to find the fields so you can add them to your post
$viewstate = ($browser->find_all_inputs( type => 'hidden', name => '__VIEWSTATE' ))[0]->value;
$validation = ($browser->find_all_inputs( type => 'hidden', name => '__EVENTVALIDATION' ))[0]->value;
# post back the formdata you need along with the session variables
$browser->post( $login_page, [ username => 'user', password => 'password, __VIEWSTATE => $viewstate, __EVENTVALIDATION => $validation ]);
# finally get back the content and make sure it looks right
print $response->content();