PHP 开发起步示例

开发y一个demo

1. 用 phpstorm 创建新项目 demo

2. 构建开发编程环境

   1. 使用 psr-4 标准化加载机制
   2. 使用 composer 构建 初始化 项目
   3. 项目目录下打开命令行运行 composer require symfony/var-dumper 引入 composer.json 的初始结构

3. 项目结构显示

   > tree -L 2 demo
   demo
   ├── composer.json
   ├── composer.lock
   └── vendor
       ├── autoload.php
       ├── composer
       └── symfony
   

4. 修改 composer.json 配置文件，配置自动加载标准，指定 psr-4, 并创建一个目录，配置信息完成映射， composer.json 文件内容如下

   {
       "autoload": {
           "psr-4": {
               "App\\": "app"
           }
       },
       "require": {
           "symfony/var-dumper": "^3.4"
       }
   }
   

   终端运行命令，让自动加载在项目中生效
   composer dump-autoload -o
   输出：Generating optimized autoload files

5. 编辑 index.php

   <?php
       
   require_once 'vendor/autoload.php';
       
   dump("this is a composer construct project");
   

   运行 php index.php 输出 this is a composer construct project

6. 测试自动加载，目录结构

   app
   ├── Helper.php
   └── task
       └── BackTask.php
   

   编辑 index.php

   <?php
       
   require_once 'vendor/autoload.php';
       
   dump("this is a composer construct project");
       
   \App\Helper::println("static function output");
       
   $helper = new \App\Helper();
   $helper->sayHello("object function output");
       
   $backTask = new \App\Task\BackTask();
   

   运行 php index.php 输出正常

遇到问题记录

问题1：

$ composer require symfony/var-dumper
The "https://packagist.phpcomposer.com/packages.json" file could not be downloaded: SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed
Failed to enable crypto
failed to open stream: operation failed
https://packagist.phpcomposer.com could not be fully loaded, package information was loaded from the local cache and may be out of date


  [InvalidArgumentException]
  Could not find a matching version of package symfony/var-dumps. Check the package spelling, your version constraint and that
  the package is available in a stability which matches your minimum-stability (stable).


require [--dev] [--prefer-source] [--prefer-dist] [--no-progress] [--no-suggest] [--no-update] [--no-scripts] [--update-no-dev] [--update-with-dependencies] [--ignore-platform-reqs] [--prefer-stable] [--prefer-lowest] [--sort-packages] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--apcu-autoloader] [--] [<packages>]...

原因：证书失效
解决：I solved the problem with the SSL error by adding the SSL certificate

// download a certificate
wget http://curl.haxx.se/ca/cacert.pem

配置 php.ini 中的 openssl.cafile= 为 下载的文件的 全路径

refer: https://stackoverflow.com/questions/27206719/composer-update-fails-while-updating-from-packagist

问题2：

$ composer require symfony/var-dumper
Using version ^3.4 for symfony/var-dumper
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 2 installs, 0 updates, 0 removals
  - Installing symfony/polyfill-mbstring (v1.19.0): Downloading (connecting...)    Failed to download symfony/polyfill-mbstring from dist: The 'https://api.github.com/repos/symfony/polyfill-mbstring/zipball/b5f7b932ee6fa802fc792eabd77c4c88084517ce' URL could not be accessed: HTTP/1.1 400 Bad Request

    Now trying to download from source
  - Installing symfony/polyfill-mbstring (v1.19.0): Cloning b5f7b932ee


  [RuntimeException]
  Failed to clone https://github.com/symfony/polyfill-mbstring.git via https, ssh protocols, aborting.
  - https://github.com/symfony/polyfill-mbstring.git
    Cloning into '/Users/user00/Documents/workspace/phptest/demo1/vendor/symfony/polyfill-mbstring'...
    fatal: unable to access 'https://github.com/symfony/polyfill-mbstring.git/': LibreSSL SSL_connect: SSL_ERROR_SYSCALL in con
  nection to github.com:443
  - git@github.com:symfony/polyfill-mbstring.git
    Cloning into '/Users/user00/Documents/workspace/phptest/demo1/vendor/symfony/polyfill-mbstring'...
    git@github.com: Permission denied (publickey).
    fatal: Could not read from remote repository.

    Please make sure you have the correct access rights
    and the repository exists.


require [--dev] [--prefer-source] [--prefer-dist] [--no-progress] [--no-suggest] [--no-update] [--no-scripts] [--update-no-dev] [--update-with-dependencies] [--ignore-platform-reqs] [--prefer-stable] [--prefer-lowest] [--sort-packages] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--apcu-autoloader] [--] [<packages>]...

原因：composer 源不可用
解决：配置国内的源

# 配置全局
composer config -g repo.packagist composer https://mirrors.cloud.tencent.com/composer

# 取消全局配置
composer config -g --unset repos.packagist

常见国内的源

composer        https://packagist.org
phpcomposer     https://packagist.phpcomposer.com
aliyun          https://mirrors.aliyun.com/composer
tencent         https://mirrors.cloud.tencent.com/composer
huawei          https://mirrors.huaweicloud.com/repository/php
laravel-china   https://packagist.laravel-china.org
cnpkg           https://php.cnpkg.org
sjtug           https://packagist.mirrors.sjtug.sjtu.edu.cn

refer: https://learnku.com/articles/15977/composer-accelerate-and-modify-mirror-source-in-china