Perl WebService::Soundcloud - how to pass track parameters while uploading to Soundcloud - perl

I'm trying to upload a sound to soundcloud using WebService::Soundcloud. I've so far been able to make a couple of GET/POST requests following the examples provided by the WebService::Soundcloud documentation.
However, I can't find a decent example anywhere on how to do an upload while passing the required parameters i.e. track, and within it, asset_data, title e.t.c. I'm wondering if I should be sending out a multipart message.
Any examples will be appreciated!
Also, here's what I have tried so far: After authenticating and getting a valid WebService::Soundcloud instance.
GET my $response = $scloud->get( '/me/tracks' );
PUT my $response = $scloud->put( '/me/tracks/91576621', JSON::to_json({track=>{title=>"My test title",description=>"My test description"}}) );
POST my $file = '/home/ski/track1.mp3';
my $asset_data = File::Slurp::read_file( $file, binmode => ':raw' );
my $response = $scloud->post('/me/tracks', '{"track":{"title":"My test title","asset_data":"'.$asset_data.'"}}' );
This fails with "Request entity contains invalid byte sequence. Please transmit valid UTF-8"

The example you provide manually constructs the JSON but doesn't take into account the binary nature of the file content which means it's unlikely to work. It's also vulnerable to abusive content changing your JSON due to lack of escaping/proper encoding.
The documentation you cite has a put example which demonstrate the content needs to be encoded into JSON and then passed to the library. I've not used this api but it's probably a simple case of using encode_json as per the examples. I'll just show an example that's equivalent to your manual encoding:
use JSON qw(encode_json);
my $asset_data = "ascii, quotes (\"'), non-ascii: \000\001\002\003";
my $content = encode_json({ track => { title => "My test title",
asset_data => $asset_data}});
print $content . "\n"; ### inspection of encoding
And this shows that JSON uses a UTF-8 representation to deal with binary data:
{"track":{"asset_data":"ascii, quotes (\"'), non-ascii: \u0000\u0001\u0002\u0003","title":"My test title"}}
The key/values are being re-ordered there but it's equivalent JSON.

Related

How can I parse character codes from a Facebook Messenger data dump into characters / emojis?

I have downloaded a data dump of my entire Facebook Messenger history in JSON format. I am trying to render messages in a basic PHP application but emojis and certain other characters are coming out like this:
I didnât get checked for id !!!
This is the corresponding JSON data:
"content": "I didn\u00e2\u0080\u0099t get checked for id !!!"
I have tried rawurldecode and utf8_decode, decodeURI and even a more complicated regex solution, but the characters keep rendering the same. I have also attempted to set UTF8 explicitly using PHP headers, but again no luck.
Here is my basic code:
$json = json_decode(file_get_contents('message_1.json'));
$messages = $json->messages;
$messages = array_reverse($messages);
foreach($messages as $m) {
if(!isset($m->content)) continue;
$ts = $m->timestamp_ms;
$date = date('d/m/Y', $ts / 1000);
echo "<strong>{$m->sender_name} ($date):</strong> $content<br>";
}
There are no errors and the messages render fine, except with any "\uXXX" characters being rendered incorrectly.
When parsing the following data:
"content": "I don\u00e2\u0080\u0099t have the key"
I would expect to see:
I don't have the key
However, my browser (Chrome) renders:
I donât have the key
Thank you in advance for any advice you can give!

How to change Mojolicious Lite default error not found to a custom json response

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.

Sending an unbuffered response in Plack

I'm working in a section of a Perl module that creates a large CSV response. The server runs on Plack, on which I'm far from expert.
Currently I'm using something like this to send the response:
$res->content_type('text/csv');
my $body = '';
query_data (
parameters => \%query_parameters,
callback => sub {
my $row_object = shift;
$body .= $row_object->to_csv;
},
);
$res->body($body);
return $res->finalize;
However, that query_data function is not a fast one and retrieves a lot of records. In there, I'm just concatenating each row into $body and, after all rows are processed, sending the whole response.
I don't like this for two obvious reasons: First, it takes a lot of RAM until $body is destroyed. Second, the user sees no response activity until that method has finished working and actually sends the response with $res->body($body).
I tried to find an answer to this in the documentation without finding what I need.
I also tried calling $res->body($row_object->to_csv) on my callback section, but seems like that ends up sending only the last call I made to $res->body, overriding all previous ones.
Is there a way to send a Plack response that flushes the content on each row, so the user starts receiving content in real time as the data is gathered and without having to accumulate all data into a veriable first?
Thanks in advance for any comments!
You can't use Plack::Response because that class is intended for representing a complete response, and you'll never have a complete response in memory at one time. What you're trying to do is called streaming, and PSGI supports it even if Plack::Response doesn't.
Here's how you might go about implementing it (adapted from your sample code):
my $env = shift;
if (!$env->{'psgi.streaming'}) {
# do something else...
}
# Immediately start the response and stream the content.
return sub {
my $responder = shift;
my $writer = $responder->([200, ['Content-Type' => 'text/csv']]);
query_data(
parameters => \%query_parameters,
callback => sub {
my $row_object = shift;
$writer->write($row_object->to_csv);
# TODO: Need to call $writer->close() when there is no more data.
},
);
};
Some interesting things about this code:
Instead of returning a Plack::Response object, you can return a sub. This subroutine will be called some time later to get the actual response. PSGI supports this to allow for so-called "delayed" responses.
The subroutine we return gets an argument that is a coderef (in this case, $responder) that should be called and passed the real response. If the real response does not include the "body" (i.e. what is normally the 3rd element of the arrayref), then $responder will return an object that we can write the body to. PSGI supports this to allow for streaming responses.
The $writer object has two methods, write and close which both do exactly as their names suggest. Don't forget to call the close method to complete the response; the above code doesn't show this because how it should be called is dependent on how query_data and your other code works.
Most servers support streaming like this. You can check $env->{'psgi.streaming'} to be sure that yours does.
Plack is middleware. Are you using a web application framework on top of it, like Mojolicious or Dancer2, or something like Apache or Starman server below it? That would affect how the buffering works.
The link above shows an example by Plack's author:
https://metacpan.org/source/MIYAGAWA/Plack-1.0037/eg/dot-psgi/echo-stream-sync.psgi
Or you can do it easily by using Dancer2 on top of Plack and Starman or Apache:
https://metacpan.org/pod/distribution/Dancer2/lib/Dancer2/Manual.pod#Delayed-responses-Async-Streaming
Regards, Peter
Some reading material for you :)
https://metacpan.org/pod/PSGI#Delayed-Response-and-Streaming-Body
https://metacpan.org/pod/Plack::Middleware::BufferedStreaming
https://metacpan.org/source/MIYAGAWA/Plack-1.0037/eg/dot-psgi/echo-stream.psgi
https://metacpan.org/source/MIYAGAWA/Plack-1.0037/eg/dot-psgi/nonblock-hello.psgi
So copy/paste/adapt and report back please

feedpp and session ID

we are using Perl and cpan Modul FeedPP to parse RSS Feeds.
The Perl script runs trough the different items of the RSS Feeds and save the link to the database, liket his:
my $response = $ua->get($url);
if ($response->is_success) {
my $feed = XML::FeedPP->new( $response->content, -type => 'string' );
foreach my $item ( $feed->get_item() ) {
my $link = $item->link();
[...]
$url contains the URL to an RSS Feed, like http://my.domain/RSS/feeds.xml
in this case, $item->link() will contain links to the RSS article, like http://my.domain/topic/myarticle.html
The Problem is, some webservers (which provides the RSS feeds) does an HTTP refer in order to add an session ID to the URL, like this: http://my.domain/RSS/feeds.xml;jsessionid=4C989B1DB91D706C3E46B6E30427D5CD.
The strange think is, that feedPP seams to add this session-ID to the link of every item. So $item->link() contain links to the RSS article, like http://my.domain/topic/myarticle.html;jsessionid=4C989B1DB91D706C3E46B6E30427D5CD
Even if the original link does not contain an session ID.
Is there a way to turn of that behavior of feedPP??
Thank you for any kind of help.
I took a look through http://metacpan.org/pod/XML::FeedPP but didn't see any way to turn have the link() method trim those session IDs for you. (I'm using XML::FeedPP in one of my scripts and the site I happen to be parsing doesn't use session IDs.)
So I think the answer is no, not currently. You could try contacting the author or filing a bug.
IMHO, the behavior is correct: uri components which follow a semi-colon are defined part of the path (configuration parameter for interpretation), so when the uri is used to make a relative url into an absolute uri it needs to be copied as well.
You expect compatible behavior with '&' parameters, but they are not equal.
https://rt.cpan.org/Ticket/Display.html?id=73895

Perl: Programatically set POST param using REST::Client module

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();