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Reflex-0.070
River stage one • 7 direct dependents • 7 total dependents
13 ++
/ Reflex::Role::Reading

NAME

Reflex::Role::Reading - add standard sysread() behavior to a class

VERSION

version 0.070

SYNOPSIS

        package InputStreaming;
        use Reflex::Role;

        attribute_parameter handle      => "handle";
        callback_parameter  cb_data     => qw( on handle data );
        callback_parameter  cb_error    => qw( on handle error );
        callback_parameter  cb_closed   => qw( on handle closed );
        method_parameter    method_stop => qw( stop handle _ );

        role {
                my $p = shift;

                my $h           = $p->handle();
                my $cb_error    = $p->cb_error();
                my $method_read = "on_${h}_readable";

                method_emit_and_stop $cb_error => "error";

                with 'Reflex::Role::Reading' => {
                        handle      => $h,
                        cb_data     => $p->cb_data(),
                        cb_error    => $cb_error,
                        cb_closed   => $p->cb_closed(),
                        method_read => $method_read,
                };

                with 'Reflex::Role::Readable' => {
                        handle      => $h,
                        cb_ready    => $method_read,
                        method_stop => $p->method_stop(),
                };
        };

        1;

DESCRIPTION

Reflex::Role::Readable implements a standard nonblocking sysread() feature so that it may be added to classes as needed.

There's a lot going on in the SYNOPSIS.

Reflex::Role::Reading is consumed to read from the InputStreaming handle. The method named in $method_read is generated to read from the handle. Three callbacks may be triggered depending on the status returned by sysread(). The "cb_data" callback will be invoked when data is read from the stream. "cb_error" will be called if there's a sysread() error. "cb_closed" will be triggered if the stream closes normally.

Reflex::Role::Readable is consumed to watch the handle for activity. Its "cb_ready" is invoked whenever the handle has data to be read. "cb_ready" is Reflex::Role::Reading's "method_read", so data is read when it's ready.

Attribute Role Parameters

handle

handle names an attribute holding the handle to be watched for readable data.

Callback Role Parameters

cb_closed

cb_closed names the $self method that will be called whenever handle has reached the end of readable data. For sockets, this means the remote endpoint has closed or shutdown for writing.

cb_closed is by default the catenation of "on_", the handle name, and "_closed". A handle named "XYZ" will by default trigger on_XYZ_closed() callbacks. The role defines a default callback that will emit a "closed" event and call stopped(), which is provided by Reflex::Role::Collectible.

Currently the second parameter to the cb_closed callback contains no parameters of note.

When overriding this callback, please be sure to call stopped(), which is provided by Reflex::Role::Collectible. Calling stopped() is vital for collectible objects to be released from memory when managed by Reflex::Collection.

cb_data

cb_data names the $self method that will be called whenever the stream for handle has provided new data. By default, it's the catenation of "on_", the handle name, and "_data". A handle named "XYZ" will by default trigger on_XYZ_data() callbacks. The role defines a default callback that will emit a "data" event with cb_data()'s parameters.

All Reflex parameterized role calblacks are invoked with two parameters: $self and an anonymous hashref of named values specific to the callback. cb_data callbacks include a single named value, data, that contains the raw octets received from the filehandle.

cb_error

cb_error names the $self method that will be called whenever the stream produces an error. By default, this method will be the catenation of "on_", the handle name, and "_error". As in on_XYZ_error(), if the handle is named "XYZ". The role defines a default callback that will emit an "error" event with cb_error()'s parameters, then will call stopped() so that streams managed by Reflex::Collection will be automatically cleaned up after stopping.

cb_error callbacks receive two parameters, $self and an anonymous hashref of named values specific to the callback. Reflex error callbacks include three standard values. errfun contains a single word description of the function that failed. errnum contains the numeric value of $! at the time of failure. errstr holds the stringified version of $!.

Values of $! are passed as parameters since the global variable may change before the callback can be invoked.

When overriding this callback, please be sure to call stopped(), which is provided by Reflex::Role::Collectible. Calling stopped() is vital for collectible objects to be released from memory when managed by Reflex::Collection.

Method Role Parameters

method_read

This role genrates a method to read from the handle in the attribute named in its "handle" role parameter. The "method_read" role parameter defines the name for this generated read method. By default, the read method is named after tha handle's attribute: "read_${$handle_name}".

EXAMPLES

TODO - I'm sure there are some.

SEE ALSO

Reflex Reflex::Role Reflex::Role::Writing Reflex::Role::Readable Reflex::Role::Streaming

"ACKNOWLEDGEMENTS" in Reflex "ASSISTANCE" in Reflex "AUTHORS" in Reflex "BUGS" in Reflex "BUGS" in Reflex "CONTRIBUTORS" in Reflex "COPYRIGHT" in Reflex "LICENSE" in Reflex "TODO" in Reflex