如何在PHP登录系统中使用Observer模式？(How to use the Observer pattern in PHP login system?)
我是设计模式的新手。 我有一个登录系统，其中包含连接到我的数据库的类和类似的东西。
但现在我想在我的PHP代码中包含一个观察者模式。 但我不知道怎么做。 例如，每当有新用户时我通知的用户。 我知道观察者模式是如何工作的，例如它做了什么。 但我不知道如何将它包含在PHP代码中。 那你如何做一个包含观察者模式的登录系统呢？
例如，这是我的数据库连接类：
private $pdo; function __construct() { $this->pdo = new PDO('mysql:host=localhost;dbname=users', '', ''); }而heres是我在登录文件中使用的代码：
if(isset($_POST['username']) && isset($_POST['password'])) { include_once("classes/database.php"); $db = new DB(); $result = $db->query("SELECT username, pass FROM users WHERE username='".$_POST['username']."' AND pass='".$_POST['password']."'"); if(isset($result[0]['username']) && isset($result[0]['password'])) { $_SESSION['username'] = $_POST['username']; header("Location: start.php?username=".$_SESSION['username']); }I am new at design patterns. And I have a log-in system with classes to connect to my database and stuff like that.
But now I want to include a observer pattern in my PHP code. But I don't know how do to that. For example a user I notified whenever there is a new user. I know how the observer pattern works, what it does for example. But I don't know how to include it to PHP code. So how do you do a login system that includes observer pattern?
For example here is my connection class to my database:
private $pdo; function __construct() { $this->pdo = new PDO('mysql:host=localhost;dbname=users', '', ''); }And heres is the code i using in the login file:
if(isset($_POST['username']) && isset($_POST['password'])) { include_once("classes/database.php"); $db = new DB(); $result = $db->query("SELECT username, pass FROM users WHERE username='".$_POST['username']."' AND pass='".$_POST['password']."'"); if(isset($result[0]['username']) && isset($result[0]['password'])) { $_SESSION['username'] = $_POST['username']; header("Location: start.php?username=".$_SESSION['username']); }
原文：https://stackoverflow.com/questions/21455944
更新时间：2022-05-13 08:05
最满意答案
无需为此使用全局变量 - 可以使用
scan来代替 - 请参阅此处 。示例 -
生成一个表 -
q)t:0N!([] time:5?.z.p; sym:5?`3; price:5?100f; size:5?10000) time sym price size ----------------------------------------------- 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 2007.05.21D04:26:13.021438816 llm 7.347808 496 2010.10.30D10:15:14.157553088 obp 31.59526 1728 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 2005.03.06D21:05:07.403334368 mho 86.17972 2318有一个简单的累加器的例子 - 注意，如果需要，函数可以访问其他的参数（见下一个例子）：
q)update someCol:{[a;x;y;z] (a+1)}\[0;time;price;size] from t time sym price size someCol ------------------------------------------------------- 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 1 2007.05.21D04:26:13.021438816 llm 7.347808 496 2 2010.10.30D10:15:14.157553088 obp 31.59526 1728 3 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 4 2005.03.06D21:05:07.403334368 mho 86.17972 2318 5假设你想得到cumilative尺寸：
q)update cuSize:{[a;x;y;z] (a+z)}\[0;time;price;size] from t time sym price size cuSize ------------------------------------------------------ 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 3994 2007.05.21D04:26:13.021438816 llm 7.347808 496 4490 2010.10.30D10:15:14.157553088 obp 31.59526 1728 6218 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 11704 2005.03.06D21:05:07.403334368 mho 86.17972 2318 14022如果你想让一个以上的var通过扫描，可以通过给它一个更复杂的结构在第一个var中包含更多的值：
q)update cuPriceAndSize:{[a;x;y;z] (a[0]+y;a[1]+z)}\[0 0;time;price;size] from t time sym price size cuPriceAndSize -------------------------------------------------------------- 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 29.07093 3994 2007.05.21D04:26:13.021438816 llm 7.347808 496 36.41874 4490 2010.10.30D10:15:14.157553088 obp 31.59526 1728 68.014 6218 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 102.1188 11704 2005.03.06D21:05:07.403334368 mho 86.17972 2318 188.2986 14022No need to use global vars for this - can use
scaninstead - see here.Example --
Generate a table -
q)t:0N!([] time:5?.z.p; sym:5?`3; price:5?100f; size:5?10000) time sym price size ----------------------------------------------- 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 2007.05.21D04:26:13.021438816 llm 7.347808 496 2010.10.30D10:15:14.157553088 obp 31.59526 1728 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 2005.03.06D21:05:07.403334368 mho 86.17972 2318Example with a simple accumilator - note, the function has access to the other args if needed (see next example):
q)update someCol:{[a;x;y;z] (a+1)}\[0;time;price;size] from t time sym price size someCol ------------------------------------------------------- 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 1 2007.05.21D04:26:13.021438816 llm 7.347808 496 2 2010.10.30D10:15:14.157553088 obp 31.59526 1728 3 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 4 2005.03.06D21:05:07.403334368 mho 86.17972 2318 5Say you wanted to get cumilative size:
q)update cuSize:{[a;x;y;z] (a+z)}\[0;time;price;size] from t time sym price size cuSize ------------------------------------------------------ 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 3994 2007.05.21D04:26:13.021438816 llm 7.347808 496 4490 2010.10.30D10:15:14.157553088 obp 31.59526 1728 6218 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 11704 2005.03.06D21:05:07.403334368 mho 86.17972 2318 14022If you wanted more than one var passed through the scan, can pack more values into the first var, by giving it a more complex structure:
q)update cuPriceAndSize:{[a;x;y;z] (a[0]+y;a[1]+z)}\[0 0;time;price;size] from t time sym price size cuPriceAndSize -------------------------------------------------------------- 2002.04.04D18:06:07.889113280 cmj 29.07093 3994 29.07093 3994 2007.05.21D04:26:13.021438816 llm 7.347808 496 36.41874 4490 2010.10.30D10:15:14.157553088 obp 31.59526 1728 68.014 6218 2005.11.01D21:15:54.022395584 dhc 34.10485 5486 102.1188 11704 2005.03.06D21:05:07.403334368 mho 86.17972 2318 188.2986 14022
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