PHP Developer Best Practices Burlington, VT PHP UG 23 April 2008 Matthew Weier O'Phinney Software Architect Zend Technologies, Ltd.

PHP Developer Best Practices Burlington, VT PHP UG

23 April 2008

About Me Software Architect, Zend Framework Development Lead: MVC, Zend_Form, Server components Scope Releases Promote and Implement best practices for team and contributors Open Source Contributor PEAR Solar Cgiapp

Software Architect, Zend Framework

Development Lead: MVC, Zend_Form, Server components

Scope Releases

Promote and Implement best practices for team and contributors

Open Source Contributor

PEAR

Solar

Cgiapp

About You Can you read your own code? Can others? Is your software tested? Is your software documented? Are you using source control? Does your team work efficiently? Do you push buggy software into production? Do you have a deployment plan? Does it include contingencies for rollbacks?

Can you read your own code? Can others?

Is your software tested?

Is your software documented?

Are you using source control?

Does your team work efficiently?

Do you push buggy software into production?

Do you have a deployment plan? Does it include contingencies for rollbacks?

What we'll cover tonight Coding Standards

Purpose of Coding Standards Efficiency Maintainability Collaboration

Efficiency

Maintainability

Collaboration

Efficiency You know you don't have a standard when: You always need to reformat code originating with others Code you wrote 6 months ago has a different visual structure than code you write today Whenever you modify old code, it breaks -- usu. due to newly introduced syntax errors e.g., missing braces in conditionals, missing commas in lists, etc.

You know you don't have a standard when:

You always need to reformat code originating with others

Code you wrote 6 months ago has a different visual structure than code you write today

Whenever you modify old code, it breaks -- usu. due to newly introduced syntax errors

e.g., missing braces in conditionals, missing commas in lists, etc.

Maintainability When following a coding standard, your code has a predictable layout both in the file system and in the layout. Easier to read code is easier to: understand maintain refactor

When following a coding standard, your code has a predictable layout both in the file system and in the layout. Easier to read code is easier to:

understand

maintain

refactor

Collaboration When a team follows a coding standard, any individual developer can pick up another developer's code and understand it, which will help them maintain and possibly refactor it. This leads to more efficient development... and thus happier customers.

Coding Standards Provide... Consistency of file system layout Consistency of code layout

Consistency of file system layout

Consistency of code layout

Use Public Standards Don't invent your own standard for you or your company. You are not special, and your PHP source code is not unique. Others have already argued the issues and you can benefit from their collective knowledge.

Why use a public standard? Objectivity Choices are no longer based on subjective preferences, but on empirical experience. Requirement when hiring or outsourcing Easily judge the candidate experience and code quality. Compatibility Use a standard that follows that of the libraries you use.

Objectivity

Choices are no longer based on subjective preferences, but on empirical experience.

Requirement when hiring or outsourcing

Easily judge the candidate experience and code quality.

Compatibility

Use a standard that follows that of the libraries you use.

What Choices Exist? PEAR Coding Standards* Zend Framework Coding Standards eZcomponents Coding Standards PHPLIB * PEAR CS actually derives from Horde

PEAR Coding Standards*

Zend Framework Coding Standards

eZcomponents Coding Standards

PHPLIB

* PEAR CS actually derives from Horde

What We'll Cover PEAR PEAR standards are the most widely used and accepted coding standards, in large part due to the number of people using PEAR as well as the general quality and explicitness of the standard. Zend Framework Only to note the additions it makes to PEAR standards.

PEAR

PEAR standards are the most widely used and accepted coding standards, in large part due to the number of people using PEAR as well as the general quality and explicitness of the standard.

Zend Framework

Only to note the additions it makes to PEAR standards.

PEAR Overview Popular component library Issues have already been debated Well known and accepted (used more than any other standard) Basis for many other projects Horde (actually, based on Horde) Solar Zend Framework AdoDB

Popular component library

Issues have already been debated

Well known and accepted (used more than any other standard)

Basis for many other projects

Horde (actually, based on Horde)

Solar

Zend Framework

AdoDB

PEAR Naming Conventions Class Names MixedCase Initial Cap Underscores separate logical package and code boundaries Examples Spreadsheet_Excel_Writer Services_Google_AdWords

Class Names

MixedCase

Initial Cap

Underscores separate logical package and code boundaries

Examples

Spreadsheet_Excel_Writer

Services_Google_AdWords

PEAR Naming Conventions Files 1:1 correspondence between class name and file name; one class per file '.php' suffix Class name underscores become directory separators Spreadsheet_Excel_Writer Spreadsheet/Excel/Writer.php No loose PHP code

Files

1:1 correspondence between class name and file name; one class per file

'.php' suffix

Class name underscores become directory separators

Spreadsheet_Excel_Writer

Spreadsheet/Excel/Writer.php

No loose PHP code

PEAR Naming Conventions Variables camelCased initial character lowercase Constants ALL_CAPS underscores for word separators Private and protected properties initial _underscore prefixes variable name

Variables

camelCased

initial character lowercase

Constants

ALL_CAPS

underscores for word separators

Private and protected properties

initial _underscore prefixes variable name

PEAR Naming Conventions Functions and Methods camelCased Initial character lowercase Private and protected methods Initial _underscore

Functions and Methods

camelCased

Initial character lowercase

Private and protected methods

Initial _underscore

PEAR Code Formatting Indentation Spaces only; no tabs Four (4) spaces per level of indentation Purpose is consistency of viewing looks the same regardless of editor Line length Suggested 75-85 character limit No shell comments (#)

Indentation

Spaces only; no tabs

Four (4) spaces per level of indentation

Purpose is consistency of viewing

looks the same regardless of editor

Line length

Suggested 75-85 character limit

No shell comments (#)

PEAR Block Formatting One True Brace Functions and Classes have the opening brace on the line following the declaration, at the same indent level Control structures keep the opening brace on the same line as the declaration All control structures use braces, no exceptions

One True Brace

Functions and Classes have the opening brace on the line following the declaration, at the same indent level

Control structures keep the opening brace on the same line as the declaration

All control structures use braces, no exceptions

PEAR Coding Standards More information Current standards: http://pear.php.net/manual/en/standards.php Proposed standards for PEAR2: http://pear.php.net/manual/en/pear2cs.php

More information

Current standards:

http://pear.php.net/manual/en/standards.php

Proposed standards for PEAR2:

http://pear.php.net/manual/en/pear2cs.php

Zend Coding Standards Follow PEAR for the most part Additions Omit closing ?> on any file containing only PHP code Abstract and Interface classes Should contain the keyword in the class name Zend_Form_Decorator_Interface Zend_Form_Decorator_Abstract More information: http://framework.zend.com/manual/en/coding-standard.html

Follow PEAR for the most part

Additions

Omit closing ?> on any file containing only PHP code

Abstract and Interface classes

Should contain the keyword in the class name

Zend_Form_Decorator_Interface

Zend_Form_Decorator_Abstract

More information:

http://framework.zend.com/manual/en/coding-standard.html

Summary Use a public coding standard Use it always

Use a public coding standard

Use it always