If you have any questions, please ask us on the B<rt-devel> mailing list:
- http://www.bestpractical.com/rt/lists.html
+ http://www.bestpractical.com/rt/lists.html
We don't always follow this guide. We are making changes throughout
our code to be in line with it. But just because we didn't do
=head2 Perl Version
-We code everything to perl 5.8.3 or higher. Complete unicode support
-requires bugfixes found in 5.8.3.
+We code everything to Perl 5.10.1 or higher.
=head2 Documentation
Any external documents, and documentation for command-line programs and
modules, should be written in POD, where appropriate. From there, they
-can be translated to many formats with the various pod2* translators.
+can be translated to many formats with the various pod2* translators.
Read the perlpod manpage before writing any POD, because although POD is
not difficult, it is not what most people are used to. It is not a
regular markup language; it is just a way to make easy documentation
number is the subversion. Odd-numbered versions are development
versions. Examples:
- 1.0.0 First release of RT 1
- 1.0.1 Second release of RT 1.0
- 1.0.10 etc.
- 1.1.0 First development release of RT 1.2 (or 2.0)
- 2.0.0 First release of RT 2
+ 1.0.0 First release of RT 1
+ 1.0.1 Second release of RT 1.0
+ 1.0.10 etc.
+ 1.1.0 First development release of RT 1.2 (or 2.0)
+ 2.0.0 First release of RT 2
Versions may end in "rc" and a number if they are release candidates:
- 2.0.0rc1 First release candiate for real 2.0.0
+ 2.0.0rc1 First release candiate for real 2.0.0
=head2 Comments
necessary comments. Use names like "$ticket_count", so you don't need to
do something like:
- # ticket count
- my $tc = 0;
+ # ticket count
+ my $tc = 0;
Include any comments that are, or might be, necessary in order for
someone else to understand the code. Sometimes a simple one-line
only. Note that a list and an array are NOT the same thing. This
is perfectly fine:
- return($user, $form, $constants);
+ return($user, $form, $constants);
An exception might be a temporary array of discrete arguments:
- my @return = ($user, $form);
- push @return, $constants if $flag;
- return @return;
+ my @return = ($user, $form);
+ push @return, $constants if $flag;
+ return @return;
Although, usually, this is better (faster, easier to read, etc.):
- if ($flag) {
- return($user, $form, $constants);
- } else {
- return($user, $form);
- }
+ if ($flag) {
+ return($user, $form, $constants);
+ } else {
+ return($user, $form);
+ }
We need to talk about Class::ReturnValue here.
=head2 System Calls
Always check return values from system calls, including open(),
-close(), mkdir(), or anything else that talks directly to the system.
+close(), mkdir(), or anything else that talks directly to the system.
Perl built-in system calls return the error in $!; some functions in
modules might return an error in $@ or some other way, so read the module's
documentation if you don't know. Always do something, even if it is
=item Users
"users" are normally users of RT, the ones hitting the site; if using
-it in any other context, specify.
+it in any other context, specify.
"system users" are user
names on the operating system. "database users" are the user names in
the database server. None of these needs to be capitalized.
Constants are in all caps; these are variables whose value will I<never>
change during the course of the program.
- $Minimum = 10; # wrong
- $MAXIMUM = 50; # right
+ $Minimum = 10; # wrong
+ $MAXIMUM = 50; # right
-Other variables are lowercase, with underscores separating the words.
+Other variables are lowercase, with underscores separating the words.
They words used should, in general, form a noun (usually singular),
unless the variable is a flag used to denote some action that should be
taken, in which case they should be verbs (or gerunds, as appropriate)
describing that action.
- $thisVar = 'foo'; # wrong
- $this_var = 'foo'; # right
- $work_hard = 1; # right, verb, boolean flag
- $running_fast = 0; # right, gerund, boolean flag
+ $thisVar = 'foo'; # wrong
+ $this_var = 'foo'; # right
+ $work_hard = 1; # right, verb, boolean flag
+ $running_fast = 0; # right, gerund, boolean flag
Arrays and hashes should be plural nouns, whether as regular arrays and
hashes or array and hash references. Do not name references with "ref"
or the data type in the name.
- @stories = (1, 2, 3); # right
- $comment_ref = [4, 5, 6]; # wrong
- $comments = [4, 5, 6]; # right
- $comment = $comments->[0]; # right
+ @stories = (1, 2, 3); # right
+ $comment_ref = [4, 5, 6]; # wrong
+ $comments = [4, 5, 6]; # right
+ $comment = $comments->[0]; # right
Make the name descriptive. Don't use variables like "$sc" when you
could call it "$story_count". See L<"Comments">.
anything other than how they are normally used, and do not use any
other variable names in their place. Some of these are:
- $self # first named argument in object method
+ $self # first named argument in object method
Subroutines (except for special cases, like AUTOLOAD and simple accessors)
begin with a verb, with words following to complete the action. Accessors
Words begin with a capital letter. They
should as clearly as possible describe the activity to be peformed, and
-the data to be returned.
+the data to be returned.
- Load(); # good
- LoadByName(); # good
- LoadById(); # good
+ Load(); # good
+ LoadByName(); # good
+ LoadById(); # good
Subroutines beginning with C<_> are special: they are not to be used
outside the current object. There is not to be enforced by the code
clear what is going on, or when it is required (such as with
map() and grep()).
- for (@list) {
- print; # OK; everyone knows this one
- print uc; # wrong; few people know this
- print uc $_; # better
- }
+ for (@list) {
+ print; # OK; everyone knows this one
+ print uc; # wrong; few people know this
+ print uc $_; # better
+ }
Note that the special variable C<_> I<should> be used when possible.
It is a placeholder that can be passed to stat() and the file test
C<_> for subsequent uses, is a performance hit. You should be
careful that the last-tested file is what you think it is, though.
- if (-d $file) { # $file is a directory
- # ...
- } elsif (-l _) { # $file is a symlink
- # ...
- }
+ if (-d $file) { # $file is a directory
+ # ...
+ } elsif (-l _) { # $file is a symlink
+ # ...
+ }
Package names begin with a capital letter in each word, followed by
lower case letters (for the most part). Multiple words should be StudlyCapped.
- RT::User # good
- RT::Database::MySQL # proper name
- RT::Display::Provider # good
- RT::CustomField # not so good, but OK
+ RT::User # good
+ RT::Database::MySQL # proper name
+ RT::Display::Provider # good
+ RT::CustomField # not so good, but OK
Plugin modules should begin with "RT::Extension::", followed by the name
-of the plugin.
+of the plugin.
=head1 Code formatting
No space before a semicolon that closes a statement.
- foo(@bar) ; # wrong
- foo(@bar); # right
+ foo(@bar) ; # wrong
+ foo(@bar); # right
Line up corresponding items vertically.
- my $foo = 1;
- my $bar = 2;
- my $xyzzy = 3;
+ my $foo = 1;
+ my $bar = 2;
+ my $xyzzy = 3;
- open(FILE, $fh) or die $!;
- open(FILE2, $fh2) or die $!;
+ open(FILE, $fh) or die $!;
+ open(FILE2, $fh2) or die $!;
- $rot13 =~ tr[abcedfghijklmnopqrstuvwxyz]
- [nopqrstuvwxyzabcdefghijklm];
+ $rot13 =~ tr[abcedfghijklmnopqrstuvwxyz]
+ [nopqrstuvwxyzabcdefghijklm];
- # note we use a-mn-z instead of a-z,
- # for readability
- $rot13 =~ tr[a-mn-z]
- [n-za-m];
+ # note we use a-mn-z instead of a-z,
+ # for readability
+ $rot13 =~ tr[a-mn-z]
+ [n-za-m];
Put blank lines between groups of code that do different things. Put
blank lines after your variable declarations. Put a blank line before a
An example:
- # this is my function!
- sub foo {
- my $val = shift;
- my $obj = new Constructor;
- my($var1, $var2);
+ # this is my function!
+ sub foo {
+ my $val = shift;
+ my $obj = new Constructor;
+ my($var1, $var2);
- $obj->SetFoo($val);
- $var1 = $obj->Foo();
+ $obj->SetFoo($val);
+ $var1 = $obj->Foo();
- return($val);
- }
+ return($val);
+ }
- print 1;
+ print 1;
=head2 Parentheses
For control structures, there is a space between the keyword and opening
parenthesis. For functions, there is not.
- for(@list) # wrong
- for (@list) # right
+ for(@list) # wrong
+ for (@list) # right
- my ($ref) # wrong
- my($ref) # right
+ my ($ref) # wrong
+ my($ref) # right
Be careful about list vs. scalar context with parentheses!
- my @array = ('a', 'b', 'c');
- my($first_element) = @array; # a
- my($first_element) = ('a', 'b', 'c'); # a
- my $element_count = @array; # 3
- my $last_element = ('a', 'b', 'c'); # c
+ my @array = ('a', 'b', 'c');
+ my($first_element) = @array; # a
+ my($first_element) = ('a', 'b', 'c'); # a
+ my $element_count = @array; # 3
+ my $last_element = ('a', 'b', 'c'); # c
Always include parentheses after functions, even if there are no arguments.
There are some exceptions, such as list operators (like print) and unary
There is no space inside the parentheses, unless it is needed for
readability.
- for ( map { [ $_, 1 ] } @list ) # OK
- for ( @list ) # not really OK, not horrible
+ for ( map { [ $_, 1 ] } @list ) # OK
+ for ( @list ) # not really OK, not horrible
On multi-line expressions, match up the closing parenthesis with either
the opening statement, or the opening parenthesis, whichever works best.
Examples:
- @list = qw(
- bar
- baz
- ); # right
+ @list = qw(
+ bar
+ baz
+ ); # right
- if ($foo && $bar && $baz
- && $buz && $xyzzy) {
- print $foo;
- }
+ if ($foo && $bar && $baz
+ && $buz && $xyzzy) {
+ print $foo;
+ }
Whether or not there is space following a closing parenthesis is
dependent on what it is that follows.
- print foo(@bar), baz(@buz) if $xyzzy;
+ print foo(@bar), baz(@buz) if $xyzzy;
Note also that parentheses around single-statement control expressions,
as in C<if $xyzzy>, are optional (and discouraged) C<if> it is I<absolutely>
flow control operator). User-supplied functions must always include
parentheses.
- print 1, 2, 3; # good
- delete $hash{key} if isAnon($uid); # good
+ print 1, 2, 3; # good
+ delete $hash{key} if isAnon($uid); # good
However, if there is any possible confusion at all, then include the
parentheses. Remember the words of Larry Wall in the perlstyle manpage:
- When in doubt, parenthesize. At the very least it will
- let some poor schmuck bounce on the % key in vi.
+ When in doubt, parenthesize. At the very least it will
+ let some poor schmuck bounce on the % key in vi.
- Even if you aren't in doubt, consider the mental welfare
- of the person who has to maintain the code after you, and
- who will probably put parens in the wrong place.
+ Even if you aren't in doubt, consider the mental welfare
+ of the person who has to maintain the code after you, and
+ who will probably put parens in the wrong place.
So leave them out when it is absoutely clear to a programmer, but if
there is any question, leave them in.
There is always a space befor the opening brace.
- while (<$fh>){ # wrong
- while (<$fh>) { # right
+ while (<$fh>){ # wrong
+ while (<$fh>) { # right
A one-line block may be put on one line, and the semicolon may be
omitted.
- for (@list) { print }
+ for (@list) { print }
Otherwise, finish each statement with a semicolon, put the keyword and
opening curly on the first line, and the ending curly lined up with the
keyword at the end.
- for (@list) {
- print;
- smell();
- }
+ for (@list) {
+ print;
+ smell();
+ }
Generally, we prefer "cuddled elses":
- if ($foo) {
- print;
- } else {
- die;
- }
+ if ($foo) {
+ print;
+ } else {
+ die;
+ }
=head2 Operators
aesthetics; e.g., sometimes the space around "**" is ommitted,
and there is never a space before a ",", but always after.
- print $x , $y; # wrong
- print $x, $y; # right
+ print $x , $y; # wrong
+ print $x, $y; # right
- $x = 2 >> 1; # good
- $y = 2**2; # ok
+ $x = 2 >> 1; # good
+ $y = 2**2; # ok
-Note that "&&" and "||" have a higher precedence than "and" and "or".
+Note that "&&" and "||" have a higher precedence than "and" and "or".
Other than that, they are exactly the same. It is best to use the lower
precedence version for control, and the higher for testing/returning
values. Examples:
- $bool = $flag1 or $flag2; # WRONG (doesn't work)
- $value = $foo || $bar; # right
- open(FILE, $file) or die $!;
+ $bool = $flag1 or $flag2; # WRONG (doesn't work)
+ $value = $foo || $bar; # right
+ open(FILE, $file) or die $!;
- $true = foo($bar) && baz($buz);
- foo($bar) and baz($buz);
+ $true = foo($bar) && baz($buz);
+ foo($bar) and baz($buz);
Note that "and" is seldom ever used, because the statement above is
better written using "if":
- baz($buz) if foo($bar);
+ baz($buz) if foo($bar);
Most of the time, the confusion between and/&&, or/|| can be alleviated
by using parentheses. If you want to leave off the parentheses then you
Try to keep the two parts to a binary operator (an operator that
has two operands) together when possible.
- print "foo" . "bar" . "baz" .
- "buz"; # wrong
+ print "foo" . "bar" . "baz" .
+ "buz"; # wrong
- print "foo" . "bar" . "baz"
- . "buz"; # right
+ print "foo" . "bar" . "baz"
+ . "buz"; # right
- print $foo unless $x == 3 && $y ==
- 4 && $z == 5; # wrong
+ print $foo unless $x == 3 && $y ==
+ 4 && $z == 5; # wrong
- print $foo unless $x == 3 && $y == 4
- && $z == 5; # right
+ print $foo unless $x == 3 && $y == 4
+ && $z == 5; # right
=head2 Other
Put space around a complex subscript inside the brackets or braces.
- $foo{$bar{baz}{buz}}; # OK
- $foo{ $bar{baz}{buz} }; # better
+ $foo{$bar{baz}{buz}}; # OK
+ $foo{ $bar{baz}{buz} }; # better
In general, use single-quotes around literals, and double-quotes
-when the text needs to be interpolated.
+when the text needs to be interpolated.
It is OK to omit quotes around names in braces and when using
the => operator, but be careful not to use a name that doubles as
a function; in that case, quote.
- $what{'time'}{it}{is} = time();
+ $what{'time'}{it}{is} = time();
When making compound statements, put the primary action first.
- open(FILE, $fh) or die $!; # right
- die $! unless open(FILE, $fh); # wrong
+ open(FILE, $fh) or die $!; # right
+ die $! unless open(FILE, $fh); # wrong
- print "Starting\n" if $verbose; # right
- $verbose && print "Starting\n"; # wrong
+ print "Starting\n" if $verbose; # right
+ $verbose && print "Starting\n"; # wrong
Use here-docs instead of repeated print statements.
- print <<EOT;
- This is a whole bunch of text.
- I like it. I don't need to worry about messing
- with lots of print statements and lining them up.
- EOT
+ print <<EOT;
+ This is a whole bunch of text.
+ I like it. I don't need to worry about messing
+ with lots of print statements and lining them up.
+ EOT
Just remember that unless you put single quotes around your here-doc
token (<<'EOT'), the text will be interpolated, so escape any "$" or "@"
Templates should use the /l filtering component to call the localisation
framework
-The string Foo!
+The string Foo!
-Should become <&|/l&>Foo!</&>
+Should become <&|/l&>Foo!</&>
-All newlines should be removed from localized strings, to make it easy to
+All newlines should be removed from localized strings, to make it easy to
grep the codebase for strings to be localized
-The string Foo
- Bar
- Baz
+The string Foo
+ Bar
+ Baz
-Should become <&|/l&>Foo Bar Baz</&>
+Should become <&|/l&>Foo Bar Baz</&>
Variable subsititutions should be moved to Locale::MakeText format
-The string Hello, <%$name %>
+The string Hello, <%$name %>
-should become <&|/l, $name &>Hello, [_1]</&>
+should become <&|/l, $name &>Hello, [_1]</&>
Multiple variables work just like single variables
-
-The string You found <%$num%> tickets in queue <%$queue%>
-should become <&|/l, $num, $queue &>You found [_1] tickets in queue [_2]</&>
+The string You found <%$num%> tickets in queue <%$queue%>
+
+should become <&|/l, $num, $queue &>You found [_1] tickets in queue [_2]</&>
When subcomponents are called in the middle of a phrase, they need to be escaped
too:
-The string <input type="submit" value="New ticket in"> <& /Elements/SelectNewTicketQueue&>
+The string <input type="submit" value="New ticket in"> <& /Elements/SelectNewTicketQueue&>
-should become <&|/l, $m->scomp('/Elements/SelectNewTicketQueue')&><input type="submit" value="New ticket in"> [_1]</&>
+should become <&|/l, $m->scomp('/Elements/SelectNewTicketQueue')&><input type="submit" value="New ticket in"> [_1]</&>
-The string <& /Elements/TitleBoxStart, width=> "40%", titleright => "RT $RT::VERSION for RT->Config->Get('rtname')", title => 'Login' &>
+The string <& /Widgets/TitleBoxStart, width=> "40%", titleright => "RT $RT::VERSION for RT->Config->Get('rtname')", title => 'Login' &>
-should become <& /Elements/TitleBoxStart,
- width=> "40%",
- titleright => loc("RT [_1] for [_2]",$RT::VERSION, RT->Config->Get('rtname')),
- title => loc('Login'),
- &>
+should become <& /Widgets/TitleBoxStart,
+ width=> "40%",
+ titleright => loc("RT [_1] for [_2]",$RT::VERSION, RT->Config->Get('rtname')),
+ title => loc('Login'),
+ &>
=item Library code
Within RT's core code, every module has a localization handle available through the 'loc' method:
-The code return ( $id, "Queue created" );
+The code return ( $id, "Queue created" );
-should become return ( $id, $self->loc("Queue created") );
+should become return ( $id, $self->loc("Queue created") );
When returning or localizing a single string, the "extra" set of parenthesis () should be omitted.
-The code return ("Subject changed to ". $self->Data );
+The code return ("Subject changed to ". $self->Data );
-should become return $self->loc( "Subject changed to [_1]", $self->Data );
+should become return $self->loc( "Subject changed to [_1]", $self->Data );
It is important not to localize the names of rights or statuses within RT's core, as there is logic that depends on them as string identifiers. The proper place to localize these values is when they're presented for display in the web or commandline interfaces.
=item Present idea to rt-devel
We may know of a better way to approach the problem, or know of an
-existing way to deal with it, or know someone else is working on it.
+existing way to deal with it, or know someone else is working on it.
This is mostly informal, but a fairly complete explanation for the need
and use of the code should be provided.
Talk about mason
component style
cascading style sheets
-
+
Talk about adding a new translation
Talk more about logging
projects / freeside.git / blobdiff