Стандарт Написання PHP Коду в Zend Framework
Огляд
Сфера застосування
Цей документ подає вказівки щодо написання коду для розробників та
команд які роблять свій вклад в розробку Zend Framework. Теми що висвітлюються:
Форматування PHP Файлів
Принципи Іменування
Стиль Написання Коду
Вбудована Документація
Цілі
Дотримання стандартів написання коду є важливим для будь якого проекту,
зокрема коли над одним проектом працюють кілька розробників.
Наявність стандартів написання коду забезпечує високу якість останнього,
меншу кількість помилок, та легкий супровід.
Форматування PHP Файлів
Загальні Положення
Не дозволено ставити тег ("?>") для файлів що містять виключно PHP код.
Закриваючий тег необовязковий для PHP а його відсутність допомагає
уникнути випадкового передчасного старту виведення, спричиненого
пробілами та іншими символами після закриваючого тегу.
ВАЖЛИВО:
Inclusion of arbitrary binary data as permitted by __HALT_COMPILER()
is prohibited from any Zend framework PHP file or files derived from them. Use of
this feature is only permitted for special installation scripts.
Indentation
Use an indent of 4 spaces, with no tabs.
Maximum Line Length
The target line length is 80 characters, i.e. developers should aim keep code
as close to the 80-column boundary as is practical. However, longer lines are
acceptable. The maximum length of any line of PHP code is 120 characters.
Line Termination
Line termination is the standard way for Unix text files. Lines must end only
with a linefeed (LF). Linefeeds are represented as ordinal 10, or hexadecimal 0x0A.
Do not use carriage returns (CR) like Macintosh computers (0x0D).
Do not use the carriage return/linefeed combination (CRLF) as Windows computers
(0x0D, 0x0A).
Naming Conventions
Classes
Zend Framework employs a class naming convention whereby the names
of the classes directly map to the directories in which they are stored.
The root level directory of Zend Framework is the "Zend/" directory,
under which all classes are stored hierarchially.
Class names may only contain alphanumeric characters. Numbers are permitted
in class names but are discouraged. Underscores are only permitted in place
of the path separator -- the filename "Zend/Db/Table.php" must map to the
class name "Zend_Db_Table".
If a class name is comprised of more than one word, the first letter of each new
word must be capitalized. Successive capitalized letters are not allowed, e.g.
a class "Zend_PDF" is not allowed while "Zend_Pdf" is acceptable.
Zend Framework classes that are authored by Zend or one of the participating
partner companies and distributed with the Framework must always start with
"Zend_" and must be stored under the "Zend/" directory hierarchy accordingly.
These are examples of acceptable names for classes:
IMPORTANT: Code that operates with the framework but is not
part of the framework, e.g. code written by a framework end-user and not Zend or
one of the framework's partner companies, must never start with "Zend_".
Interfaces
Interface classes must follow the same conventions as other classes (see above),
however must end with the word "Interface", such as in these examples:
Filenames
For all other files, only alphanumeric characters, underscores, and the dash
character ("-") are permitted. Spaces are prohibited.
Any file that contains any PHP code must end with the extension ".php". These
examples show the acceptable filenames for containing the class names from the
examples in the section above:
File names must follow the mapping to class names described above.
Functions and Methods
Function names may only contain alphanumeric characters. Underscores are not permitted.
Numbers are permitted in function names but are discouraged.
Function names must always start with a lowercase letter. When a function name consists
of more than one word, the first letter of each new word must be capitalized. This is
commonly called "camelCase" formatting.
Verbosity is encouraged. Function names should be as verbose as is practical to enhance the
understandability of code.
These are examples of acceptable names for functions:
For object-oriented programming, accessors for objects should always be prefixed with
either "get" or "set". When using design patterns, such as the singleton or factory
patterns, the name of the method should contain the pattern name where practical to
make the pattern more readily recognizable.
For methods on objects that are declared with the "private" or "protected" construct,
the first character of the variable name must be a single underscore. This is the only
acceptable usage of an underscore in a method name. Methods declared "public"
may never start with an underscore.
Functions in the global scope ("floating functions") are permitted but discouraged.
It is recommended that these functions should be wrapped in a static class.
Variables
Variable names may only contain alphanumeric characters. Underscores are not permitted.
Numbers are permitted in variable names but are discouraged.
For class member variables that are declared with the "private" or "protected" construct,
the first character of the variable name must be a single underscore. This is the only
acceptable usage of an underscore in a variable name. Member variables declared "public"
may never start with an underscore.
Like function names (see section 3.3, above) variable names must always start with a
lowercase letter and follow the "camelCaps" capitalization convention.
Verbosity is encouraged. Variables should always be as verbose as practical. Terse variable
names such as "$i" and "$n" are discouraged for anything other than the smallest loop contexts.
If a loop contains more than 20 lines of code, the variables for the indices need to have more
descriptive names.
Constants
Constants may contain both alphanumeric characters and the underscore. Numbers are permitted
in constant names.
Constants must always have all letters capitalized.
To enhance readablity, words in constant names must be separated by underscore characters. For
example, EMBED_SUPPRESS_EMBED_EXCEPTION is permitted but
EMBED_SUPPRESSEMBEDEXCEPTION is not.
Constants must be defined as class members by using the "const" construct. Defining constants
in the global scope with "define" is permitted but discouraged.
Coding Style
PHP Code Demarcation
PHP code must always be delimited by the full-form, standard PHP tags:
]]>
Short tags are never allowed. For files containing only PHP code, the
closing tag must always be omitted (See ).
Strings
String Literals
When a string is literal (contains no variable substitutions), the apostrophe or
"single quote" must always used to demarcate the string:
String Literals Containing Apostrophes
When a literal string itself contains apostrophes, it is permitted to demarcate
the string with quotation marks or "double quotes". This is especially encouraged
for SQL statements:
The above syntax is preferred over escaping apostrophes.
Variable Substitution
Variable substitution is permitted using either of these two forms:
For consistency, this form is not permitted:
String Concatenation
Strings may be concatenated using the "." operator. A space must always
be added before and after the "." operator to improve readability:
When concatenating strings with the "." operator, it is permitted to
break the statement into multiple lines to improve readability. In these
cases, each successive line should be padded with whitespace such that the
"."; operator is aligned under the "=" operator:
Arrays
Numerically Indexed Arrays
Negative numbers are not permitted as indices.
An indexed array may be started with any non-negative number, however
this is discouraged and it is recommended that all arrays have a base index of 0.
When declaring indexed arrays with the array construct, a trailing space must be
added after each comma delimiter to improve readability:
It is also permitted to declare multiline indexed arrays using the "array" construct.
In this case, each successive line must be padded with spaces such that beginning of
each line aligns as shown below:
Associative Arrays
When declaring associative arrays with the array construct, it is encouraged
to break the statement into multiple lines. In this case, each successive line must be
padded with whitespace such that both the keys and the values are aligned:
'firstValue',
'secondKey' => 'secondValue');]]>
Classes
Class Declaration
Classes must be named by following the naming conventions.
The brace is always written on the line underneath the class name ("one true brace" form).
Every class must have a documentation block that conforms to the PHPDocumentor standard.
Any code within a class must be indented four spaces.
Only one class is permitted per PHP file.
Placing additional code in a class file is permitted but discouraged. In these files, two blank lines must separate the class from any additional PHP code in the file.
This is an example of an acceptable class declaration:
Class Member Variables
Member variables must be named by following the variable naming conventions.
Any variables declared in a class must be listed at the top of the class, prior
to declaring any methods.
The var construct is not permitted. Member variables always declare
their visibility by using one of the private, protected,
or public constructs. Accessing member variables directly by making
them public is permitted but discouraged in favor of accessor
methods (set/get).
Functions and Methods
Function and Method Declaration
Functions must be named by following the naming conventions.
Methods inside classes must always declare their visibility by using
one of the private, protected,
or public constructs.
Like classes, the brace is always written on the line underneath the
function name ("one true brace" form).
There is no space between the
function name and the opening parenthesis for the arguments.
Functions in the global scope are strongly discouraged.
This is an example of an acceptable function declaration in a class:
NOTE: Pass-by-reference is permitted in the function declaration only:
Call-time pass-by-reference is prohibited.
The return value must not be enclosed in parentheses. This can hinder readability
and can also break code if a method is later changed to return by reference.
bar);
}
/**
* RIGHT
*/
public function bar()
{
return $this->bar;
}
}]]>
Function and Method Usage
Function arguments are separated
by a single trailing space after the comma delimiter. This is an example of an
acceptable function call for a function that takes three arguments:
Call-time pass-by-reference is prohibited. See the function declarations section
for the proper way to pass function arguments by-reference.
For functions whose arguments permit arrays, the function call may include the
"array" construct and can be split into multiple lines to improve readability. In
these cases, the standards for writing arrays still apply:
Control Statements
If / Else / Elseif
Control statements based on the if and elseif
constructs must have a single space before the opening parenthesis of the conditional,
and a single space after the closing parenthesis.
Within the conditional statements between the parentheses, operators must be separated
by spaces for readability. Inner parentheses are encouraged to improve logical grouping
of larger conditionals.
The opening brace is written on the same line as the conditional statement. The closing
brace is always written on its own line. Any content within the braces must be
indented four spaces.
For "if" statements that include "elseif" or "else", the formatting conventions are as shown
in the following examples:
PHP allows for these statements to be written without braces in some circumstances.
The coding standard makes no differentiation and all "if", "elseif" or "else" statements
must use braces.
Use of the "elseif" construct is permitted but highly discouraged in favor of the
"else if" combination.
Switch
Control statements written with the "switch" construct must have a single space before
the opening parenthesis of the conditional statement, and also a single space after
the closing parenthesis.
All content within the "switch" statement must be indented four spaces. Content under
each "case" statement must be indented an additional four spaces.
The construct default may never be omitted from a switch statement.
NOTE: It is sometimes useful to write a case statement which falls through
to the next case by not including a break or return in that case. To distinguish
these cases from bugs, any case statement where break or return are
omitted must contain the comment "// break intentionally omitted".
Inline Documentation
Documentation Format
All documentation blocks ("docblocks") must be compatible with the phpDocumentor format.
Describing the phpDocumentor format is beyond the scope of this document.
For more information, visit: http://phpdoc.org/
All source code files written for Zend Framework or that operate with the framework
must contain a "file-level" docblock at the top of each file and a "class-level" docblock
immediately above each class. Below are examples of such docblocks.
Files
Every file that contains PHP code must have a header block at the top of the file that
contains these phpDocumentor tags at a minimum:
Classes
Every class must have a docblock that contains these phpDocumentor tags at a minimum:
Functions
Every function, including object methods, must have a docblock that contains at a minimum:
A description of the function
All of the arguments
All of the possible return values
It is not necessary to use the "@access" tag because the access level is already known
from the "public", "private", or "protected" construct used to declare the function.
If a function/method may throw an exception, use @throws: