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#PHP Note

environment

Connect to mssql database

You have to install php7.0-sybase first.

$ sudo apt-get install php7.0-sybase

語法

calling class' function by string

call_user_func([$this, $your_function_name]);
// or
$this->{$your_function_name}();

parent

If you override parent class' function and want to run with old function, use parent::yourFunctionName();

class A
{
	public function printing()
	{
		echo "a.printing() ";
	}
}

class B extends A
{
	public function printing()
	{
		parent::printing();
		echo "b.printing()";
	}
}

$b = new B;
$b->printing();
// a.printing() b.printing()

使用 preg_replace() 取代字串

  • Use () to catch parameter you want to retain, it will convert to $1, $2, ...
$timestamp = '2015-06-06 14:00:00';

$timeConvert = preg_replace(
    '/(\d{4})-(\d{2})-(\d{2})(\s\d{2}):(\d{2}):(\d{2})/',
    "$1年$2月$3日$4時$5分$6秒",
    $timestamp
);

echo $timeConvert;
// output:
// 2015年06月06日 14時00分00秒

getcwd()

取得目前執行之檔案的絕對路徑

echo getcwd();

curl

example of issuing a post request

$cu = curl_init();
$url = 'http://kettan.dev.com/admin/post/category/test';
$data = [
    'name' => 'Kettan',
    // ...
];
$options = [
    CURLOPT_URL => $url,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => $data,
];
curl_setopt_array($cu, $options);
curl_exec($cu);
curl_close($cu);

CLI(Command Line) Colors (bash)

Color code is here

echo "\033[0;31m Your messages\033[0m \n";
// Use "\033" to tell php it's a color code.
// "[0;31m" defines which color to show, in this case, the color is light red.
// "[0m" tells php color code is stoped here, or you'll see all words be changed under your message.

array_unique()

同index的重複value只保留一個

$a = [1,2,2,3];   
$b = [
	['neo'] => [4,5,5,6,7,7]
];
$a1 = array_unique($a);
$b1 = array_unique($b);
// $a1 = [1,2,3]
// $b1 = [
//    ['neo'] => [4,5,6,7]
// ]

array_values()

把陣列的index重新訂為0~

$array = [
  'c' => 1,
  'b' => 2,
  'z' => 3
];
$rearrange = array_values($array);
// $rearrange = [
//   0 => 1,
//   1 => 2,
//   2 => 3
// ]

json_decode() 取回(陣列|物件)的方法

json_decode($jString);         #回傳物件
json_decode($jString, true);   #回傳陣列

刪除一個已存在的cookie

參考

if(isset($_COOKIE['login']))
    setcookie('login', null, -1);

unset()

清除陣列

$a = [1,2,3];
unset($a[1]);
// $a = [1,3];

創造時間變數

$dateTime = date("Y-m-d H:i:s", mktime(date('H'), date('i'), date('s'), date('m'), date('d'), date('Y')));
// 順序為: h時 i分 s秒 m月 d日 Y年   時可為 h->十二小時制度 H->二十四小時制
$time = date("ah:i:s");
// "ah"的a用來顯示"am"或"pm"

修改已存在的時間

如果要幫 $time = "2014-12-24" 加3個月的話 參考

$time = "2014-12-24";
$add_mon = 3;
$pre_time = $time;
$next_time = strtotime("+$add_mon month", strtotime($pre_time));
$time = date("Y-m-d", $next_time);
echo $time;
// 輸出2015-06-24

計算剩餘天數

$dueDate = "2016-01-01";
$now = time();
$countdownDays = ceil( (strtotime($dueDate) - $now) / 86400 );
$s = '';
if ($countdownDays > 1)
    $s  = 's';
echo "There is {$countdownDays}day{$s} till $dueDate."

時間戳記加減運算

$a = '2015-01-20 07:00:00';
$b = '2015-01-20 20:00:00';
$c = strtotime($b)-strtotime($a);
echo gmdate("H:i:s", $c);
// 輸出13:00:00

判斷一個變數是否為數字

$a = '123';
$b = 123;
$c = 'yam23';
echo is_numeric($a); // 1
echo is_numeric($b); // 1
echo is_numeric($c); // 0

======

some common questions

Save compressed text into MySQL's BLOB type

  • To BLOB
function textToMySQLBLOB($text = '') : string
{
    // @see http://php.net/manual/en/function.bin2hex.php
    $hexed = bin2hex($text);
    // Add '0x' in front of $hexed,
    // so MySQL can accept it as BLOB type
    return '0x' . $hexed;
}
  • To text
function MySQLBLOBToText($blob = '') : string
{
    // Remove '0x' from $blob
    $hexed = substr($blob, 2);
    $bStr = hex2bin($hexed);
    return $bStr;
}

About DateInterval

official doc
ref
The DateInterval constructor's format:

  • Use prefix P before assign year, month, date (Ymd) relative times
$tenDays = new DateInterval('P10D');
  • Use prefix T after P and before assign hour, minute, second (His) relative times
$oneHour = new DateInterval('PT1H');
  • Examples
new DateInterval('P1Y2M3D'); // P開頭表示日期，一年二個月又三天

new DateInterval('PT4H5M6S'); // T開頭表示時間，四小時五分又六秒

new DateInterval('P1Y2M3DT4H5M6S'); // 合併起來，一年二個月三天四小時五分又六秒

new DateInterval('P3M'); // 三個月

new DateInterval('PT1H'); // 一小時

Count working days

ref
Use native object DateTime, DateInterval, DatePeriod to count working days.

function number_of_working_days($from, $to) {
    $workingDays = [1, 2, 3, 4, 5]; # date format = N (1 = Monday, ...)
    $holidayDays = ['*-12-25', '*-01-01', '2013-12-23']; # variable and fixed holidays

    $from = new DateTime($from);
    $to = new DateTime($to);
    $to->modify('+1 day');
    $interval = new DateInterval('P1D');
    $periods = new DatePeriod($from, $interval, $to);

    $days = 0;
    foreach ($periods as $period) {
        if (!in_array($period->format('N'), $workingDays)) continue;
        if (in_array($period->format('Y-m-d'), $holidayDays)) continue;
        if (in_array($period->format('*-m-d'), $holidayDays)) continue;
        $days++;
    }
    return $days;
}

NOTE (new DateTime($yourDateTime))->format('N') returns code of weekday, 7 represents Sunday, 1 represents Monday, and 6 represents Saturday.

$weekdaysMap = [
	7, // Sunday
	1, // Monday
	2, // Tuesday
	3, // Wednesday
	4, // Thursday
	5, // Friday
	6, // Saturday
];

Sent an AJAX request, but $_POST is empty

To retrive data from request payload, you may use:

<?php
$payload = json_decode(file_get_contents('php://input'), true);

Display images that are placed out from web root

ref - get file extension
ref - readfile()

$file = '/foo/bar/aPhoto.jpg';
header('Content-type:image/jpeg');
readfile($file);

Reduce memories from unusing parameters

unset($someParam);
// way faster
$someParam = null;

ERROR: Can't use method return value in write context

ref

function hi() {
	return 'hi';
}
$s = hi();

// In this case, php will output: FATAL ERROR Can't use function return value in write context on line number 9.
// Use empty($s) instead.
if (empty(hi()) {
	echo 'empty';
} else {
	echo 'has value';
}

You cannot let empty() judge method's return value, put a parameter into empty() so that php won't blame.

print out code's executing time

function example() {
    // bla bla...
}
example();
$time = microtime(true) - $_SERVER['REQUEST_TIME_FLOAT'];
echo "It spent $time in function calls\n";

移除空白

$str = " This line contains\tliberal \r\n use of whitespace.\n\n";

// 移除前後空白字
$str = trim($str);

// 移除重覆的空白
$str = preg_replace('/\s(?=\s)/', '', $str);

// 移除非空白的間距變成一般的空白
$str = preg_replace('/[\n\r\t]/', ' ', $str);

minutes convert to hours and minutes

ref
mktime()

date("H:i", mktime(0, $yourMinuteInteger));

關於PHP

  • 電腦中PHP的位置
$ which php
  • php.ini的路徑可以在phpinfo();內看到

PHP session id

安裝PHP後，PHP compiler會根據該電腦的CPU內核(內核ID每個CPU獨一無二)與其他數據做出__session id__
php session id是可以重設的，php compiler預設的php session id就叫php session id

傳送PHP字串(含有'或"的變數)給javascript變數接

參考

var myvar = <?php echo json_encode($myVarValue); ?>;

操作 cookie、session 之前不能輸出網頁內容

如:
不能

echo 'aaa';
setcookie(...);

不能

<p>Hello</p>
<?php
setcookie(...);
?>

參考

將array_unique過的陣列轉成json

$a = array(1,2,2,3,3);
$b = array_unique($a);                   // $b = [1,2,3]
echo json_encode($b);                    // 輸出 {"0":1,"1":2,"3":3}
echo json_encode(array_values($b));      // 輸出 [1,2,3]

=====

Skills

傳送變數至Closure(anonymous funciton)裡

參考

// 在function(...)後面加上use($parameter_you_want)
$name = 'Name';
Mail::send('email.view', [...], function($message) use($name) {...});

php://input

參考
php://input returns all the raw data after the HTTP-headers of the request.
If you have a ajax request with JSON data, you may use

file_get_contents("php://input");

to get data.

使用php重新整理(或跳轉)頁面

參考

echo "<meta http-equiv='refresh' content='0; url='http://www.google.com'>";

這裡的0代表0秒跳轉
還有另一個是header()，使用header()前頁面不能有任何輸出如echo(), print_f()等等

header("Location: http://www.google.com");

不過最方便的還是用js...

$url = 'www.google.com';
echo "<script>window.location.replace('$url');</script>";

在遞迴函式裡面使用靜態變數加快function的速度

參考

function fib($n)
{



	if($n < 2)
		return $n;
	$f[$n] = fib($n-2) + fib($n-1);
	return $f[$n];
}

echo fib(30), "\n";

上面這段$f為普通變數，執行時間__5.59556889534__秒
下面這段把$f宣告為為靜態變數，執行時間__0.002144813537__秒

function fib($n)
{
	static $f = array();
	if(isset($f[$n]))
		return $f[$n];
	if($n < 2)
		return $n;
	$f[$n] = fib($n-2) + fib($n-1);
	return $f[$n];
}

echo fib(30), "\n";

在雙引號字串內印出變數

$juice = 'orange';

echo "I drank some juice made of $juices";    // 無法輸出$juice變數
echo "I drank some juice made of {$juice}s";  // 輸出$juice變數

// 也可以輸出陣列內容
$juice = ['orange', 'apple', 'watermelon'];
echo "I drank some juice made of {$juice[1]}s";

命名慣例

Class

首字大寫

ConsoleController

class' attribute

開頭加個m，其他首字大寫

class HelloController
{
    var $mStrAbc;
    var $mHelloAttribute;
}

function

首字小寫，其後駝峰式

function doSomeThing(){}

variable

全小寫，使用_隔開

$first_string;
$second_string;

Coding Style

PSR-2

參考

  • 純php檔案的結尾__一定__不要有?>
  • 檔案結束後最下方__一定__要有一行空白
  • 縮排__一定__要用空白，__一定不能__用tab
  • class名稱宣告完成後左大括號__一定__要在其下一行，右大括號__一定__要在程式本體結束的下一行
  • class的屬性與方法__一定__要宣告可視屬性public, private, protected...
  • function名稱與params__一定__要連在一起，其後左大括號__一定__要在其下一行，右大括號__一定__要在方法本體結束的下一行
<?php

class SomeClass
{
    public $ParamA = null;
    
    public $ParamB = false;
    
    public function __construct($p1, $p2, $p3 = [])
    {
        // do something
    }
}

WTF part of integration with Facebook apps

fb.ui share

===

error message:
An error occurred. Please try again later.

or

應用程式的設定不接受這個網址。: 應用程式的設定不接受所提供之一或多個網址。網址必須符合網站網址或畫布（Canvas）應用程式網址；或者，網域必須是應用程式網域的子網域之一

facebook API Version v2.3
ref
ref2 (check the most thumbed answer)

  • yell WTF
  • go to facebook developers page
  • go to settings
  • click Advanced
  • check Client OAuth Settings
  • ensure Web OAuth Login is yes
  • add your site url into Valid OAuth redirect URIs

===