PHP-разработчики, как и в любом другом языке, могут написать код, который по шкале качества оценивается от совершенно ужасного, до отличного. Выработка полезных навыков поможет вам повысить качество и производительность.
Если во время написания кода не придерживаться определенных рекомендаций, то это может стать причиной ошибок, а так же помех при дальнейшем поддержании программы. Следующие рекомендации, применяемые при написании PHP-кода, помогут вам избежать подводных камней:
Давайте правильные имена
Разбивайте код на небольшие части
Документируйте код
Обрабатывайте ошибки
Никогда, никогда не делайте копи-пейст!
<?php
function getNBDay($d)
{
switch($d) {
case 5:
case 6:
case 7:
return 1;
default:
return ($d + 1);
}
}
$day = 5;
$nextDay = getNBDay($day);
echo ("Next day is: " . $nextDay . "\n");
?>
<?php
define ('MONDAY', 1);
define ('TUESDAY', 2);
define ('WEDNESDAY', 3);
define ('THURSDAY', 4);
define ('FRIDAY', 5);
define ('SATURDAY', 6);
define ('SUNDAY', 7);
/*
*
* @param $dayOfWeek
* @return int Day of week, with 1 being Monday and so on.
*/
function findNextBusinessDay($dayOfWeek)
{
$nextBusinessDay = $dayOfWeek;
switch($dayOfWeek) {
case FRIDAY:
case SATURDAY:
case SUNDAY:
$nextBusinessDay = MONDAY;
break;
default:
$nextBusinessDay += 1;
break;
}
return $nextBusinessDay;
}
$day = FRIDAY;
$nextBusDay = findNextBusinessDay($day);
echo ("Next day is:" . $nextBusDay . "\n");
?>
<?php
function writeRssFeed($user)
{
// Get the DB connection information
// look up the user's preferences...
$link = mysql_connect('mysql_host', 'mysql_user', 'mysql_password')
OR die(mysql_error());
// Query
$perfsQuery = sprintf("SELECT max_stories FROM user_perfs WHERE user= '%s'",
mysql_real_escape_string($user));
$result = mysql_query($query, $link);
$max_stories = 25; // default it to 25;
if ($row = mysql_fetch_assoc($result)) {
$max_stories = $row['max_stories'];
}
// go get my data
$perfsQuery = sprintf("SELECT * FROM stories WHERE post_date = '%s'",
mysql_real_escape_string());
$result = mysql_query($query, $link);
$feed = "<rss version=\"2.0\">" .
"<channel>" .
"<title>My Great Feed</title>" .
"<link>http://www.example.com/feed.xml</link>" .
"<description>The best feed in the world</description>" .
"<language>en-us</language>" .
"<pubDate>Tue, 20 Oct 2008 10:00:00 GMT</pubDate>" .
"<lastBuildDate>Tue, 20 Oct 2008 10:00:00 GMT</lastBuildDate>" .
"<docs>http://www.example.com/rss</docs>" .
"<generator>MyFeed Generator</generator>" .
"<managingEditor>editor@example.com</managingEditor>" .
"<webMaster>webmaster@example.com</webMaster>" .
"<ttl>5</ttl>";
// build the feed...
while ($row = mysql_fetch_assoc($result)) {
$title = $row['title'];
$link = $row['link'];
$description = $row['description'];
$date = $row['date'];
$guid = $row['guid'];
$feed .= "<item>";
$feed .= "<title>" . $title . "</title>";
$feed .= "<link>" . $link . "</link>";
$feed .= "<description> " . $description . "</description>";
$feed .= "<pubDate>" . $date . "</pubDate>";
$feed .= "<guid>" . $guid . "</guid>";
$feed .= "</item>";
}
$feed .= "</rss";
// write the feed out to the server...
echo($feed);
}
?>
<?php
function createRssHeader()
{
return "<rss version=\"2.0\">" .
"<channel>" .
"<title>My Great Feed</title>" .
"<link>http://www.example.com/feed.xml</link>" .
"<description>The best feed in the world</description>" .
"<language>en-us</language>" .
"<pubDate>Tue, 20 Oct 2008 10:00:00 GMT</pubDate>" .
"<lastBuildDate>Tue, 20 Oct 2008 10:00:00 GMT</lastBuildDate>" .
"<docs>http://www.example.com/rss</docs>" .
"<generator>MyFeed Generator</generator>" .
"<managingEditor>editor@example.com</managingEditor>" .
"<webMaster>webmaster@example.com</webMaster>" .
"<ttl>5</ttl>";
}
function createRssFooter()
{
return "</channel></rss>";
}
function createRssItem($title, $link, $desc, $date, $guid)
{
$item .= "<item>";
$item .= "<title>" . $title . "</title>";
$item .= "<link>" . $link . "</link>";
$item .= "<description> " . $description . "</description>";
$item .= "<pubDate>" . $date . "</pubDate>";
$item .= "<guid>" . $guid . "</guid>";
$item .= "</item>";
return $item;
}
function getUserMaxStories($db_link, $default)
{
$perfsQuery = sprintf("SELECT max_stories FROM user_perfs WHERE user= '%s'",
mysql_real_escape_string($user));
$result = mysql_query($perfsQuery, $db_link);
$max_stories = $default;
if ($row = mysql_fetch_assoc($result)) {
$max_stories = $row['max_stories'];
}
return $max_stories;
}
function writeRssFeed($user)
{
// Get the DB connection information
$settings = parse_ini_file("rss_server.ini");
// look up the user's preferences...
$link = mysql_connect($settings['db_host'], $settings['user'],
$settings['password']) OR die(mysql_error());
$max_stories = getUserMaxStories($link, 25);
// go get my data
$newsQuery = sprintf("SELECT * FROM stories WHERE post_date = '%s'",
mysql_real_escape_string(time()));
$result = mysql_query($newsQuery, $link);
$feed = createRssHeader();
$i = 0;
// build the feed...
while ($row = mysql_fetch_assoc($result)) {
if ($i < $max_stories) {
$title = $row['title'];
$link = $row['link'];
$description = $row['description'];
$date = $row['date'];
$guid = $row['guid'];
$feed .= createRssItem($title, $link, $description, $date, $guid);
$i++;
} else {
break;
}
}
mysql_close($link);
$feed .= createRssFooter();
// write the feed out to the server...
echo($feed);
}
?>
<?php
class ResultMessage
{
private $severity;
private $message;
public function __construct($sev, $msg)
{
$this->severity = $sev;
$this->message = $msg;
}
public function getSeverity()
{
return $this->severity;
}
public function setSeverity($severity)
{
$this->severity = $severity;
}
public function getMessage()
{
return $this->message;
}
public function setMessage($msg)
{
$this->message = $msg;
}
}
function cntMsgs($messages)
{
$n = 0;
/* iterate through the messages... */
foreach($messages as $m) {
if ($m->getSeverity() == 'Error') {
$n++; // add one to the result;
}
}
return $n;
}
$messages = array(new ResultMessage("Error", "This is an error!"),
new ResultMessage("Warning", "This is a warning!"),
new ResultMessage("Error", "This is another error!"));
$errs = cntMsgs($messages);
echo("There are " . $errs . " errors in the result.\n");
?>
<?php
/**
* The ResultMessage class holds a message that can be returned
* as a result of a process. The message has a severity and
* message.
*
* @author nagood
*
*/
class ResultMessage
{
private $severity;
private $message;
/**
* Constructor for the ResultMessage that allows you to assign
* severity and message.
* @param $sev See {@link getSeverity()}
* @param $msg
* @return unknown_type
*/
public function __construct($sev, $msg)
{
$this->severity = $sev;
$this->message = $msg;
}
/**
* Returns the severity of the message. Should be one
* "Information", "Warning", or "Error".
* @return string Message severity
*/
public function getSeverity()
{
return $this->severity;
}
/**
* Sets the severity of the message
* @param $severity
* @return void
*/
public function setSeverity($severity)
{
$this->severity = $severity;
}
public function getMessage()
{
return $this->message;
}
public function setMessage($msg)
{
$this->message = $msg;
}
}
/*
* Counts the messages with the given severity in the array
* of messages.
*
* @param $messages An array of ResultMessage
* @return int Count of messages with a severity of "Error"
*/
function countErrors($messages)
{
$matchingCount = 0;
foreach($messages as $m) {
if ($m->getSeverity() == "Error") {
$matchingCount++;
}
}
return $matchingCount;
}
$messages = array(new ResultMessage("Error", "This is an error!"),
new ResultMessage("Warning", "This is a warning!"),
new ResultMessage("Error", "This is another error!"));
$errs = countErrors($messages);
echo("There are " . $errs . " errors in the result.\n");
?><?php
// Get the actual name of the
function convertDayOfWeekToName($day)
{
$dayNames = array(
"Sunday",
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday",
"Saturday");
return $dayNames[$day];
}
echo("The name of the 0 day is: " . convertDayOfWeekToName(0) . "\n");
echo("The name of the 10 day is: " . convertDayOfWeekToName(10) . "\n");
echo("The name of the 'orange' day is: " . convertDayOfWeekToName('orange') . "\n");
?><?php
/**
* This is the exception thrown if the day of the week is invalid.
* @author nagood
*
*/
class InvalidDayOfWeekException extends Exception { }
class InvalidDayFormatException extends Exception { }
/**
* Gets the name of the day given the day in the week. Will
* return an error if the value supplied is out of range.
*
* @param $day
* @return unknown_type
*/
function convertDayOfWeekToName($day)
{
if (! is_numeric($day)) {
throw new InvalidDayFormatException('The value \'' . $day . '\' is an ' .
'invalid format for a day of week.');
}
if (($day > 6) || ($day < 0)) {
throw new InvalidDayOfWeekException('The day number \'' . $day . '\' is an ' .
'invalid day of the week. Expecting 0-6.');
}
$dayNames = array(
"Sunday",
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday",
"Saturday");
return $dayNames[$day];
}
echo("The name of the 0 day is: " . convertDayOfWeekToName(0) . "\n");
try {
echo("The name of the 10 day is: " . convertDayOfWeekToName(10) . "\n");
} catch (InvalidDayOfWeekException $e) {
echo ("Encountered error while trying to convert value: " . $e->getMessage() . "\n");
}
try {
echo("The name of the 'orange' day is: " . convertDayOfWeekToName('orange') . "\n");
} catch (InvalidDayFormatException $e) {
echo ("Encountered error while trying to convert value: " . $e->getMessage() . "\n");
}
?><?php
/**
* Counts the number of messages found in the array of
* ResultMessage with the getSeverity() value of "Error"
*
* @param $messages An array of ResultMessage
* @return unknown_type
*/
function countErrors($messages)
{
$matchingCount = 0;
foreach($messages as $m) {
if ($m->getSeverity() == "Error") {
$matchingCount++;
}
}
return $matchingCount;
}
/**
* Counts the number of messages found in the array of
* ResultMessage with the getSeverity() value of "Warning"
*
* @param $messages An array of ResultMessage
* @return unknown_type
*/
function countWarnings($messages)
{
$matchingCount = 0;
foreach($messages as $m) {
if ($m->getSeverity() == "Warning") {
$matchingCount++;
}
}
return $matchingCount;
}
/**
* Counts the number of messages found in the array of
* ResultMessage with the getSeverity() value of "Information"
*
* @param $messages An array of ResultMessage
* @return unknown_type
*/
function countInformation($messages)
{
$matchingCount = 0;
foreach($messages as $m) {
if ($m->getSeverity() == "Information") {
$matchingCount++;
}
}
return $matchingCount;
}
$messages = array(new ResultMessage("Error", "This is an error!"),
new ResultMessage("Warning", "This is a warning!"),
new ResultMessage("Error", "This is another error!"));
$errs = countErrors($messages);
echo("There are " . $errs . " errors in the result.\n");
?><?php
/*
* Counts the messages with the given severity in the array
* of messages.
*
* @param $messages An array of ResultMessage
* @return int Count of messages matching $withSeverity
*/
function countMessages($messages, $withSeverity)
{
$matchingCount = 0;
foreach($messages as $m) {
if ($m->getSeverity() == $withSeverity) {
$matchingCount++;
}
}
return $matchingCount;
}
/**
* Counts the number of messages found in the array of
* ResultMessage with the getSeverity() value of "Error"
*
* @param $messages An array of ResultMessage
* @return unknown_type
*/
function countErrors($messages)
{
return countMessages($messages, "Errors");
}
/**
* Counts the number of messages found in the array of
* ResultMessage with the getSeverity() value of "Warning"
*
* @param $messages An array of ResultMessage
* @return unknown_type
*/
function countWarnings($messages)
{
return countMessages($messages, "Warning");
}
/**
* Counts the number of messages found in the array of
* ResultMessage with the getSeverity() value of "Warning"
*
* @param $messages An array of ResultMessage
* @return unknown_type
*/
function countInformation($messages)
{
return countMessages($messages, "Information");
}
$messages = array(new ResultMessage("Error", "This is an error!"),
new ResultMessage("Warning", "This is a warning!"),
new ResultMessage("Error", "This is another error!"));
$errs = countErrors($messages);
echo("There are " . $errs . " errors in the result.\n");
?>2009 © Olmish.com
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