I'm trying to understand this Perl code…
If there is one stream it works, if there are 2 or more streams it warns with odd number of elements in anonymous hash. It seems to return an array in that case. How do I add the array elements correctly to @streams? It appears to add correctly for the HASH case in the if clause. Is the else clause bunk?
my $x = $viewedProjectDataObj->{streams};
if (ref($x) eq 'HASH') {
push(@streams, $x->{id});
} elsif (ref($x) eq 'ARRAY') {
print "$x\n";
print "@$x\n";
my @array = @$x;
foreach my $obj (@array) {
print "in $obj\n";
print Dumper( $obj);
push(@streams, ($obj->{id}) );
}
}
print "streamcount " . @streams % 2;
print Dumper(@streams);
my $stream_defect_filter_spec = {
'streamIdList' => @streams,
'includeDefectInstances' => 'true',
'includeHistory' => 'true',
};
my @streamDefects = $WS->get_stream_defects($defectProxy, \@cids, $stream_defect_filter_spec);
print Dumper(@streamDefects);
I'm adding the next lines…
if ($defectSummary->{owner} eq "Various") {
foreach (@streamDefects) {
if (exists($_->{owner})) {
$defectSummary->{owner} = $_->{owner};
last;
}
}
}
my $diref = $streamDefects[0]->{defectInstances};
if ($diref) {
my $defectInstance;
if (ref($diref) eq 'HASH') {
$defectInstance = $diref;
} elsif (ref($diref) eq 'ARRAY') {
$defectInstance = @{$diref}[0];
} else {
die "Unable to handle $diref (".ref($diref).")";
}
It now errors with
Web API returned error code S:Server: calling getStreamDefects: No stream found
for name null.
$VAR1 = -1;
me
Can't use string ("-1") as a HASH ref while "strict refs" in use at xyz-handler.pl line 317.
some Dumper output
$VAR1 = {
'streamIdList' => [
{
'name' => 'asdfasdfadsfasdfa'
},
{
'name' => 'cpp-62bad47d63cfb25e76b29a4801c61d8d'
}
],
'includeDefectInstances' => 'true',
'includeHistory' => 'true'
};
Best Answer
The list assigned to a hash is a set of key/value pairs, which is why the number of elements must be even.
Because the
=>
operator is little more than a comma, and the@streams
array is flattened in the list, thisis equivalent to this
so I hope you can see that you will get the warning if you have an even number of elements in the array.
To fix things you need the value of the hash element to be an array reference, which is a scalar and won't upset the scheme of things
that way you can access the array elements as
etc.
And by the way you can tidy up your code substantially by letting
map
do what it's good at: