.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is >0, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{\
.    if \nF \{\
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{\
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\" ========================================================================
.\"
.IX Title "GraphQL::PubSub 3pm"
.TH GraphQL::PubSub 3pm "2022-03-27" "perl v5.34.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
GraphQL::PubSub \- publish/subscribe
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 5
\&  use GraphQL::PubSub;
\&  my $pubsub = GraphQL::PubSub\->new;
\&  $pubsub\->subscribe(\*(Aqchannel1\*(Aq, \e&callback);
\&  $pubsub\->publish(\*(Aqchannel1\*(Aq, 1);
\&  $pubsub\->unsubscribe(\*(Aqchannel1\*(Aq, \e&callback);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
Encapsulates the publish/subscribe logic needed by GraphQL::Subscription.
.SH "METHODS"
.IX Header "METHODS"
.SS "subscribe($channel, \e&callback[, \e&error_callback])"
.IX Subsection "subscribe($channel, &callback[, &error_callback])"
Registers the given callback on the given channel.
.PP
The optional second \*(L"error\*(R" callback is called as a method on the object
when an exception is thrown by the first callback. If not given, the
default is for the subscription to be cancelled with \*(L"unsubscribe\*(R". The
error callback will be called with values of the channel, the original
callback (to enable unsubscribing), the exception thrown, then the values
passed to the original callback. Any exceptions will be ignored.
.SS "unsubscribe($channel, \e&callback)"
.IX Subsection "unsubscribe($channel, &callback)"
Removes the given callback from the given channel.
.ie n .SS "publish($channel, @values)"
.el .SS "publish($channel, \f(CW@values\fP)"
.IX Subsection "publish($channel, @values)"
Calls each callback registered on the given channel, with the given values.