chapter.standard.coding.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- $Id: chapter.coding.xml 584 2013-05-15 05:13:17Z netkiller $ -->
<section id="coding">
	<title>编码风格</title>
	<screen>
https://code.google.com/p/google-styleguide/
http://lxr.linux.no/linux/Documentation/CodingStyle
http://perldoc.perl.org/perlstyle.html
http://www.gnu.org/prep/standards/
	</screen>
	<section id="java">
		<title>java 编程规范</title>
		<section>
			<title>一个输入多个出口</title>
			<programlisting>
			<![CDATA[
			Object row = input.readLine();
			if (row != null) {
				if (this.process != null) {
					row = this.process.run(row);
				}
				if (row != null) {
					boolean outputStatus = this.output.write(row);
					if (this.position != null && outputStatus) {

						this.position.set(row);

					}
				}
			}			
			]]>
			</programlisting>			
		</section>
		<section>
			<title>Spring Data JPA</title>
			<programlisting>
			<![CDATA[
	@Autowired
	private TableRepostitory tableRepostitory;
	
	@Autowired
	private JdbcTemplate jdbcTemplate;
	
	@PersistenceContext 
	private EntityManager entityManager; 
			]]>
			</programlisting>
		</section>
		
	</section>
	<section id="php">
		<title>php 文件</title>
		<para>http://www.php-fig.org</para>
		<section>
			<title>格式与 编码</title>
			<para>使用 UNIX 风格换行, 请在你的编辑器内调整</para>
			<screen>
UNIX (LF或"\n")
MAC OS (CR 或"\r")
Windows CRLF \r\n
			</screen>
			<para>源码文件使用 UTF-8</para>
			<para>有些IDE环境 UTF-8 BOM</para>
		</section>
		<section>
			<title>循环嵌套</title>
			<para>if, while, for, foreach, do ... loop, switch... 等的嵌套必须小于等于3层</para>
			<para>如下面的例子，可读性极差。</para>
			<screen>
if (xxx){
	if (xxx){
		if(xxx){
			if(xxx){
				if(xxx){

				}
			}
		}
		if(xxx){
			if(xxx){
			}
		}
	}
	if (xxx){
		if(xxx){
			if(xxx){
			}
		}
		if(xxx){
			if(xxx){
			}
		}
	}
}
			</screen>
			<para>加以改造</para>
			<screen>
func aaa(p){
	if(p){
		if(xxx){
		}
	}
}
func bbb(b){
	if(b){
		if(xxx){
			if(xxx){

			}
		}
	}
}

if(xxx){
	aaa(xxx)
}
if(b){
	bbb(b)
}			</screen>
		</section>
		<section>
			<title>取出行尾的空格以及多余的换行符</title>
			<para>一个空格占用一个字节,换行符Window是两个字节\r\n, Unix与Mac占用一个字节</para>
		</section>
		<section>
			<title>php 标签</title>
			<para>禁止这样使用</para>
			<screen>
			<![CDATA[
<?
...
?>
			]]>
			</screen>
			<para>正确的使用方法</para>
			<screen>
			<![CDATA[
<?php
...

or

<?php
...
?>
			]]>
			</screen>
		</section>

		<section>
			<title>头部注释</title>
			<screen>
			<![CDATA[
<?php
/**
 * Project Name
 *
 * @author     $Author: netkiller $
 * @copyright  Copyright (c) 2012 Company
 * @version    $Id: chapter.coding.xml 584 2013-05-15 05:13:17Z netkiller $
 */

<?php
/**
 * Project Name
 *
 * @author     $Author: netkiller $
 * @license    GNU General Public License 2.0
 * @version    $Id: chapter.coding.xml 584 2013-05-15 05:13:17Z netkiller $
 */
			]]>
			</screen>
		</section>
	</section>
	<section id="coding.string">
		<title>String</title>
		<para>双引号要处理字符串转义，性能上不如单引号，如果你不需要转义字符串，或者字符串中不含原转译字符，建议你使用单引号</para>
		<screen>
print("string")
		</screen>
		<para>每次输出会检索特殊字符串如： \r, \n, \t, \0xFF 等等</para>
		<screen>
print('string')
		</screen>
	</section>
	<section id="coding.db">
		<title>Database</title>
		<para>使用pdo_mysql替代mysql</para>
		<para>错误的写法，通过字符串链接拼接sql语句极容易出现注入漏洞</para>
		<screen>
$sql = "select * from table where id=".$id;
$sql = "select * from table where id='".$id."'";
$sql = "INSERT INTO fruit(name, colour) VALUES ('".$name."', '".$colour."')";
		</screen>
		<para>正确的写法</para>
		<screen>
$sql = "select * from table where id=?";
$sql = "INSERT INTO fruit(name, colour) VALUES (?, ?)";
		</screen>
		<screen>
		<![CDATA[
$sql = <<<____SQL
     CREATE TABLE IF NOT EXISTS `ticket_hist` (
       `tid` int(11) NOT NULL,
       `trqform` varchar(40) NOT NULL,
       `trsform` varchar(40) NOT NULL,
       `tgen` datetime NOT NULL,
       `tterm` datetime,
       `tstatus` tinyint(1) NOT NULL
     ) ENGINE=ARCHIVE COMMENT='ticket archive';
____SQL;
		]]>
		</screen>

		<section>
			<title>结果集使用注意事项</title>
			<para>返回数据库查询结果有几种形式</para>
			<para>数组形式</para>
			<screen>
			<![CDATA[
Array
(
    [0] => banana
    [1] => yellow
)

Array
(
    [NAME] => banana
    [COLOUR] => yellow
)
			]]>
			</screen>
			<para>对象形式</para>
			<screen>
Object
(
	Obj->NAME
	Obj->COLOUR
)
			</screen>
			<para>正确的使用方式</para>
			<screen>
print($row[name])
print($row->name)
			</screen>
			<para>错误的使用使方式</para>
			<screen>
print($row[0])
			</screen>
			<para>避免使用 "*"查询，一会影响性能，二增加带宽开销</para>
			<screen>
$sql = "select * from tab where status=0 limit 1";
			</screen>
			<para>如果程序使用$row[1]读取结果，有可能当数据库结构改变，增加字段，字段顺序发生变化，输出数据都会出错</para>
		</section>
		<section>
			<title>索引</title>
			<para>下面的例子，不会使用索引</para>
			<screen>
$sql = "select id, name, created from tab where id != 100";
			</screen>
			<screen>
EXPLAIN select * from members where id != '1010';			索引失效
EXPLAIN select count(*) from members where id != '1010';	索引有效
			</screen>
		</section>
		<section>
			<title>缓存</title>
			<screen>

			</screen>
			<para>下面的例子，数据不会缓存查询结果</para>
			<screen>
$sql = "select id, name, created from tab where created=now()";
			</screen>
		</section>
	</section>
</section>