- conf_files
- conf_files returns your conf_files array.
my @conf_files = $class->conf_files();
You can also programmatically add a new conf_file this
way.
$class->conf_files('/path/to/new/conf.file', '/path/to/other/conf.file'); #, etc
However, it'd be better to specify your conf file at use
time.
use Mail::Bulkmail::Object 3.00 "/path/to/conf.file";
This also (naturally) works in all subclasses.
use Mail::Bulkmail 3.00 "/path/to/conf.file";
use Mail::Bulkmail::Dynamic 3.00 "/path/to/conf/file";
and so on.
Note that adding on via ->conf_files or importing puts onto
the FRONT of the @conf_files array, i.e., those
conf files are more significant.
So,
@conf_files = qw(/path/to/file /path/to/file2);
use Mail::Bulkmail::Object 3.00 "/path/to/file3" "/path/to/file4";
Mail::Bulkmail::Object->conf_files("/path/to/file5", "/path/to/file6");
print Mail::Bulkmail::Object->conf_files;
#prints out /path/to/file5 /path/to/file6 /path/to/file3 /path/to/file4 /path/to/file path/to/file2
Note that you don't *need* conf files, you can still specify
all information at construction time, or via mutators, or whatever. But
a conf file can make your life a lot easier.
- add_attr
- add_attr adds object attributes to the class.
Okay, now we're going to get into some philosophy. First of
all, let me state that I *love* Perl's OO implementation. I usually get
smacked upside the head when I say that, but I find it really easy to
use, work with, manipulate, and so on. And there are things that you can
do in Perl's OO that you can't in Java or C++ or the like. Perl, for
example, can have *totally* private values that are completely
inaccessible (lexicals, natch). private vars in the other languages can
be redefined or tweaked or subclassed or otherwise gotten around in some
form. Not Perl.
And I obviously just adore Perl anyway. I get funny looks when
I tell people that I like perl so much because it works the way I think.
That bothers people for some reason.
Anyway, as much as I like how it works, I don't like the fact
that there's no consistent object type. An object is, of course, a
blessed ((thingie)) (scalar, array, code, hash, etc) reference. And
there are merits to using any of those things, depending upon the
situation. Hashes are easy to work with and most similar to traditional
objects.
$object->{$attribute} = $value;
And whatnot. Arrays are much faster (typically 33% in tests
I've done), but they suck to work with.
$object->[15] = $value; #the hell is '15'?
(
by the way, you can make this easier with variables defined to return the value, i.e.
$object->[$attribute] = $value; #assuming $attribute == 15
)
Scalars are speciality and coderefs are left to the magicians.
Don't get me wrong, coderefs as objects are nifty, but they can be
tricky to work with.
So, I wanted a consistent interface. I'm not going to claim
credit for this idea, since I think I originally read it in Object
Oriented Programming in Perl (Damien's book). In fact, I think the error
reporting method I use was also originally detailed in there. Anyway, I
liked it a lot and decided I'd implement my own version of it.
Basically, attributes are accessed and mutated via
methods.
$object->attribute($value);
For all attributes. This way, the internal object can be
whatever you'd like. I used to use mainly arrays for the speed boost,
but lately I use hashes a lot because of the ease of dumping and reading
the structure for debugging purposes. But, with this consistent
interface of using methods to wrapper the attributes, I can change the
implementation of the object (scalar, array, hash, code, whatever) up in
this module and *nothing* else needs to change.
Say you implemented a giant system in OO perl. And you chose
hashrefs as your "object". But then you needed a big speed
boost later, which you could easily get by going to arrays. You'd have
to go through your code and change all instances of
$object->{$attribute} to
$object->[15] or whatever. That's an awful
lot of work.
With everything wrappered up this way, changes can be made in
the super object class and then automagically populate out everywhere
with no code changes. Spiffy stuff.
There are some disadvantages, there is a little more overhead
for doing the additional method call, but it's usually negligible. And
you can't do nice things like:
$object->{$attribute}++;
you'd have to do
$object->attribute($object->attribute + 1);
Which is annoying. But I think it's offset by the consistent
interface regardless of what your underlying object is.
Enough with the philosophy, though. You need to know how this
works.
It's easy enough:
package Some::Class;
Some::Class->add_attr('foo');
Now your Some::Class objects have a foo attribute, which can
be accessed as above. If called with a value, it's the mutator which
sets the attribute to the new value and returns the new value. If called
without one, it's the accessor which returns the value.
my $obj = Some::Class->new();
$obj->foo('bar');
print $obj->foo(); #prints bar
print $obj->foo('boo'); #prints boo
print $obj->foo(); #prints boo
add_attr calls should only be in your module. Never in your
program. And they really should be defined up at the top.
Internally, an add_attr call creates a function inside your
package of the name of the attribute which reflects through to the
internal _accessor method which handles the mutating and accessing.
There is another syntax for add_attr, to define a different
internal accessor:
Some::Class->add_attr(['foo', 'other_accessor']);
This creates method called 'foo' which talks to a separate
accessor, in this case "other_accessor" instead of going to
_accessor. This is useful if you want to create a validating method on
your attribute.
Additionally, it creates a normal method going to _accessor
called '_foo', which is assumed to be the internal attribute slot your
other accessor with use. In generall, for a given "attribute",
"_attribute" will be created for internal use.
"other_accessor" will get the object as the first
arg (as always) and the name of the internal method as the second.
Example:
Some::Class->add_attr(['foo', 'other_accessor']);
$obj->foo('bee');
sub other_accessor {
my $self = shift;
my $method = shift; # "_foo", in this example
if (@_){
my $val = shift; # "bee", in this example
if ($val == 7){
return $self->$method($val);
}
else {
return $self->error("Cannot store value...foo must be 7!");
};
}
else {
return $self->$method();
};
};
And, finally, you can also pass in additional arguments as
static args if desired.
Some::Class->add_attr(['foo', 'other_accessor'], 'bar');
$obj->foo('bee');
sub other_accessor {
my $self = shift;
my $method = shift;
my $static = shift; #'bar' in our example
my $value = shift; #'bee' in our example
.
.
.
};
All easy enough. Refer to any subclasses of this class for further examples.
- add_class_attr
- This is similar to add_attr, but instead of adding object attributes, it
adds class attributes. You cannot have object and class attributes
with the same name. This is by design. (error is a special case)
Some::Class->add_attr('foo'); #object attribute foo
Some::Class->add_class_attr('bar'): #class attribute bar
print $obj->foo();
print Some::Class->bar();
Behaves the same as an object method added with add_attr,
mutating with a value, accessing without one. Note that add_class_attr
does not have the capability for additional internal methods or static
values. If you want those on a class method, you'll have to wrapper the
class attribute yourself on a per case basis.
Note that you can access class attributes via an object (as
expected), but it's frowned upon since it may be confusing.
class attributes are automatically initialized to any values
in the conf file upon adding, if present.
- add_tricke_class_attr
- It's things like this why I really love Perl.
add_trickle_class_attr behaves the same as add_class_attr with
the addition that it will trickle the attribute down into any class as
it is called. This is useful for subclasses.
Watch:
package SuperClass;
SuperClass->add_class_attr('foo');
SuperClass->foo('bar');
package SubClass;
@ISA = qw(SuperClass);
print SubClass->foo(); #prints bar
print SuperClass->foo(); #prints bar
print SuperClass->foo('baz'); #prints baz
print SubClass->foo(); #prints baz
print SubClass->foo('dee'); #prints dee
print SuperClass->foo(); #prints dee
See? The attribute is still stored in the super class, so
changing it in a subclass changes it in the super class as well.
Usually, this behavior is fine, but sometimes you don't want that to
happen. That's where add_trickle_class_attr comes in. Its first call
will snag the value from the SuperClass, but then it will have its own
attribute that's separate.
Again, watch:
package SuperClass;
SuperClass->add_trickle_class_attr('foo');
SuperClass->foo('bar');
package SubClass;
@ISA = qw(SuperClass);
print SubClass->foo(); #prints bar
print SuperClass->foo(); #prints bar
print SuperClass->foo('baz'); #prints baz
print SubClass->foo(); #prints bar
print SubClass->foo('dee'); #prints dee
print SuperClass->foo(); #prints baz
This is useful if you have an attribute that should be unique
to a class and all subclasses. These are equivalent:
package SuperClass;
SuperClass->add_class_attr('foo');
package SubClass
SubClass->add_class_attr('foo');
and
package SuperClass;
SuperClass->add_trickle_class_attr('foo');
You'll usually just use add_class_attr. Only use
trickle_class_attr if you know you need to, since you rarely would.
There is a *slight* bit of additional processing required for trickled
accessors.
trickled class attributes are automatically initialized to any
values in the conf file upon adding, if present.
- error and errcode
- error rocks. All error reporting is set and relayed through error. It's a
standard accessor, and an *almost* standard mutator. The difference is
that when used as a mutator, it returns undef (or an empty list) instead
of the value mutated to.
If a method fails, it is expected to return undef (or an empty
list) and set error.
example:
sub someMethod {
my $self = shift;
my $value = shift;
if ($value > 10){
return 1; #success
}
else {
return $self->error("Values must be greater than 10");
};
};
$object->someMethod(15) || die $object->error; #succeeds
$object->someMethod(5) || die $object->error; #dies with an error..."Values must be greater than 10"
Be warned if your method can return '0', this is a valid
successful return and shouldn't give an error. But most of the time,
you're fine with "true is success, false is failure"
As you can see in the example, we mutate the error attribute
to the value passed, but it returns undef.
However, error messages can change and can be difficult to
parse. So we also have an error code, accessed by errcode. This is
expected to be consistent and machine parseable. It is mutated by the
second argument to ->error
example:
sub someMethod {
my $self = shift;
my $value = shift;
if ($value > 10){
return 1; #success
}
else {
return $self->error("Values must be greater than 10", "ERR77");
};
};
$object->someMethod(15) || die $object->error; #succeeds
$object->someMethod(5) || die $object->errcode; #dies with an error code ... "ERR77"
If your code is looking for an error, read the errcode. if a
human is looking at it, display the error. Easy as pie.
Both classes and objects have error methods.
my $obj = Some::Class->new() || die Some::Class->error();
$obj->foo() || die $obj->error();
Note that error is a special method, and not just a normal
accessor or class attribute. As such:
my $obj = Some::Class->new();
Some::Class->error('foo');
print $obj->error(); #prints undef
print Some::Class->error(); #prints foo
i.e., you will not get a class error message by calling
->error on an object.
There is also an optional third paramenter..."not
logged", which sounds horribly ugly, I know. But it is a bit of an
after-market hack, so it's to be expected. The third argument does what
you'd think, it prevents the error message from being logged.
$self->error("This is an error message", "code", "not logged");
Any true value may be passed for the 3rd argument, but
something that makes it obvious what it's doing is recommended, hence my
use of 'not logged'. This is useful for bubbling up errors.
$class->error($self->error, $self->errcode, 'not logged');
The reason is that the error was already logged when it was
stored in $self. So you'd end up logging it
twice in your error file, which is very confusing. So it's recommended
to use the three argument form for errors that are bubbling up, but not
elsewhere.
As of 3.06, if an error is returned in a list context, an
empty list will be returned instead of undef. undef is still returned in
a scalar context.
- errcode
- errcode is an accessor ONLY. You can only mutate the errcode via error,
see above.
print $obj->errcode;
Both objects and classes have errcode methods.
my $obj = Some::Class->new() || die Some::Class->errcode();
$obj->foo() || die $obj->errcode();
Where possible, the pod will note errors that a method is
known to be able to return. Please note that this will never be
an all inclusive list of all error codes that may possibly ever be
returned by this method. Only error codes generated by a particular
method will be listed.
- errstring
- errstring is just a quick alias for:
$bulk->error . ": " . $bulk->errcode;
Nothing more.
- errvals
- similar to errstring, but returns the error and errcode in an array. This
is great for bubbling up error messages.
$attribute = $obj->foo() || return $self->error($obj->errvals);
- read_conf_file
- read_conf_file will read in the conf files specified in the
@conf_files array up at the top.
You can also pass in a list of conf files to read, in most to
least significant order, same as the @conf_files
array.
my $conf = Mail::Bulkmail::Object->read_conf_file();
or
my $conf = Mail::Bulkmail::Object->read_conf_file('/other/conf.file');
If you pass in a list of conf files, then the internal
@conf_files array is bypassed.
$conf is a hashref of hashrefs. the
main keys are the package names, the values are the hashes of the values
for that object.
Example:
#conf file
define package Mail::Bulkmail
use_envelope = 1
Trusting @= duplicates
define package Mail::Bulkmail::Server
Smtp = your.smtp.com
Port = 25
$conf = {
'Mail::Bulkmail' => {
'use_envelope' => 1,
'Trusting' => ['duplicates']
},
'Mail::Bulkmail::Server' => {
'Smtp' => 'your.smtp.com',
'Port' => 25
}
};
read_conf_file is called at object initialization. Any
defaults for your object are read in at this time. You'll rarely need to
read the conf file yourself, since at object creation it is read and
parsed and the values passed on.
Be sure to read up on the conf file structure,
below
The conf file is only re-read if it has been modified since
the last time it was read.
this method is known to be able to return MBO002 - Invalid
conf file
- gen_handle
- returns a filehandle in a different package. Useful for when you need to
open filehandles and pass 'em around.
my $handle = Mail::Bulkmail->gen_handle();
open ($handle, "/path/to/my/list");
my $bulk = Mail::Bulkmail->new(
'LIST' => $handle
);
You never need to use gen_handle if you don't want to. It's
used extensively internally, though.
- new
- Finally! The constructor. It's very easy, for a minimalist object,
do this:
my $obj = Class->new() || die Class->error();
Ta da! You have an object. Any attributes specified in the
conf file will be loaded into your object. So if your conf file defines
'foo' as 'bar', then $obj->foo will now equal
'bar'.
If you'd like, you can also pass in method/value pairs to the
constructor.
my $obj = Class->new(
'attribute' => '17',
'foo' => 'baz',
'method' => '88'
) || die Class->error();
This is (roughly) the same as:
my $obj = Class->new() || die Class->error();
$obj->attribute(17) || die $obj->error();
$obj->foo('baz') || die $obj->error();
$obj->method(88) || die $obj->error();
Any accessors or methods you'd like may be passed to the
constructor. Any unknown pairs will be silently ignored. If you pass a
method/value pair to the constructor, it will override any equivalent
method/value pair in the conf file.
Additionally, if you need to set up values in your object,
this is the place to do it. Note that setting default values should
probably be done in the conf file, but if you need to populate a data
structure into a method, do it here.
package SubClass;
@ISA = qw(SuperClass);
sub new {
return shift->new(
'servers' => [],
'connections' => {},
@_
);
};
This will cause your SubClass to use the normal constructor,
but get default values of the empty data structures specified.
- init
- The object initializer. Arguably more important than the constructor, but
not something you need to worry about. The constructor calls it
internally, and you really shouldn't touch it or override it. But I wanted
it here so you know what it does.
Simply, it iterates through the conf file and mutates any of
your object attributes to the value specified in the conf file. It then
iterates through the hash you passed to ->new() and does the
same thing, overriding any conf values, if necessary.
init is smart enough to use all super class values defined in
the conf file, in hierarchy order. So if your conf file contains:
define package SuperClass
foo = 'bar'
And you're creating a new SubClass object, then it will get
the default of foo = 'bar' as in the conf file, despite the fact that it
was not defined for your own package. Naturally, the more significant
definition is used.
define package SuperClass
foo = 'bar'
define package SubClass
foo = 'baz'
SuperClass objects will default foo to 'bar', SubClass objects
will default foo to 'baz'
this method is known to be able to return
MBO003 - could not initialize value to conf value
MBO004 - could not initialize value to constructor value
MBO006 - odd number of elements in hash assignment
- isa_path
- This is mainly used by the conf reader, but I wanted to make it publicly
accessible. Given a class, it will return an arrayref containing all of
the superclasses of that class, in inheritence order.
Note that once a path is looked up for a class, it is cached.
So if you dynamically change @ISA, it won't be
reflected in the return of isa_path. Obviously, dynamically changing
@ISA is frowned upon as a result.
- getNextLine
- getNextLine is called on either a filehandleref, an arrayref, or a coderef
$obj->getNextLine(\*FOO);
will return the next line off of FOO;
$obj->getNextLine(\@foo);
will shift the next line off of @foo
and return it.
$obj->getNextLine(\&foo);
will call foo($obj) and return whatever the function
returns.
Note that your bulkmail object is the first argument passed to
your function. It's not called as a method, but the object is still the
first argument passed.
This is mainly used with attribues going through
_file_accessor.
package SomeClass;
SomeClass->add_attr(['FOO', '_file_accessor'], "<");
my $obj = SomeClass->new(
FOO => \&foo
) || die SomeClass->error();
my $val = $obj->getNextLine($obj->FOO);
- logToFile
- logToFile is the opposite of getNextLine, it writes out a value instead of
reading it.
logToFile is called on either a filehandleref, an arrayref, or
a coderef
$obj->logToFile(\*FOO, "bar");
will append a new line to FOO, "bar"
$obj->logToFile(\@foo, "bar");
will push the value "bar" onto the end of
@foo
$obj->logToFile(\&foo, "bar");
will call foo($obj, "bar")
Note that your bulkmail object is the first argument passed to
your function. It's not called as a method, but the object is still the
first argument passed.
This is mainly used with attribues going through
_file_accessor.
package SomeClass;
SomeClass->add_attr(['FOO', '_file_accessor'], ">>");
my $obj = SomeClass->new(
FOO => \&foo
) || die SomeClass->error();
my $val = $obj->logToFile($obj->FOO, "valid address);
Internally, logToFile calls convert_to_scalar on the value it
is called with.
This method is known to be able to return:
MBO005 - cannot log to file
- convert_to_scalar
- called by logToFile. used to convert the value passed to a scalar.
Mail::Bulkmail::Object's convert_to_scalar method will only
handle scalars, it will dereference scalarrefs, or return scalar values.
This method will also strip out any carriage returns or newlines within
the scalar before returning it. If passed by reference, your original
variable will not be modified.
This is useful to subclass if you ever want to log values
other than simple scalars
- ERRFILE
- This is an optional log file to keep track of any errors that occur.
ERRFILE may be either a coderef, globref, arrayref, or string
literal.
If a string literal, then Mail::Bulkmail::Object will attempt
to open that file (in append mode) as your log:
$bulk->ERRFILE("/path/to/my/error.file");
If a globref, it is assumed to be an open filehandle in append
mode:
open (E, ">>/path/to/my/error.file");
$bulk->ERRFILE(\*E);
if a coderef, it is assumed to be a function to call with the
address as an argument:
sub E { print "ERROR : ", shift, "\n"}; #or whatever your code is
$bulk->ERRFILE(\&E);
if an arrayref, then bad addresses will be pushed on to the
end of it
$bulk->ERRFILE(\@errors);
Use whichever item is most convenient, and
Mail::Bulkmail::Object will take it from there.
It is recommended you turn on ERRFILE in a debugging
envrionment, and leave it off in production. You probably shouldn't be
getting errors in a production environment, but there may be internal
errors that you're not even aware of, so you'll end up filling up that
file. And there's the slight additional overhead.
Keep it on in production if you know what you're doing, off
otherwise.