http://www.perlmonks.org?node_id=1017344


in reply to Getting error while decoding JSON object via POST method

The error is on these two lines.

my $jsonText = $q->param('inputdata');
my $outputDataRef = $json->decode($inputData);

[download]

If you'd used strict Perl would have told you about the undeclared variable $inputData.

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

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Re^2: Getting error while decoding JSON object via POST method
by perlCrazy (Monk) on Feb 06, 2013 at 07:20 UTC
    Sorry for not providing the complete code. updated the code just now. problem is not with variable definition, please check the error:
    malformed JSON string, neither array, object, number, string or atom, at character offset 0 (before "(end of string)"
[reply]

      Have you printed out your JSON data string at the receiving end to see what you get there? An empty string gives the same error message:

      >perl -MJSON -e "print JSON->new->decode('')"
malformed JSON string, neither array, object, number, string or atom, 
+at character offset 0 (before "(end of string)") at -e line 1.

      [download]

      I think you are trying to pass the data around in a very bad manner:

      <c> "/projectname/restfulapi?inputdata=$jsonData"; <c>

      If you send POST data, please read HTTP::Request on how to send POST data. If you want to send the data in an URI, please encode it properly using URI::Encode.

[reply]
[d/l]
        mo luck!! tried like this: 
        my $inData = { "name" => "test", "id" => "test", "test" => [1,2,3,4],}
+;
my $json   = JSON->new->utf8->allow_nonref;
my $jsonData = $json->encode($inData);
print Dumper($jsonData);
##Output of dumper : 
$VAR1 = '{"test":[1,2,3,4],"name":"test","id":"test"}';

# post set post request
my $req = HTTP::Request->new('POST', $rest_url);
$req->content($jsonData);
my $response  = $iua->request($req);

        [download]
        getting same error.
[reply]
[d/l]

      This error message occurs when you pass the empty string or an undefined variable to be decoded by JSON, JSON::PP or JSON::XS.

      So I'd suggest that even with the updated code, the problem is related to the initialization of $jsonText - it appears to be undef.

      package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name
[reply]
[d/l]

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