# 管理PHP Library的利器Composer

在之前試玩[Ruby On Rails](http://rubyonrails.org/)的時候就覺得有[Gem](http://rubygems.org/)一整個就是超好用的吶!!所以前陣子公司導入 Gitlab 之後順勢要我研究一下 PHP 的[Composer](http://getcomposer.org/)，想不到還有支援 Github。所以做個紀錄。

### 安裝 PHP Composer

安裝在各自專案時

```bash
mkdir /var/www/html/example
sudo curl -s https://getcomposer.org/installer | sudo php
```

![install composer](https://lh4.googleusercontent.com/-1d9vXwf_95M/Uchd7udmlMI/AAAAAAAAADY/w8qUK7xXyFY/w850-h263-no/composer-1.PNG)

> 我安裝時有出現警告訊息是因為我的 PHP 版本是 5.3.3 他建議我升級到 5.3.4 或更高，否則可能導致 Composer 不穩定

我自己是安裝在/usr/local/bin

```bash
cd /usr/local/bin
sudo curl -s https://getcomposer.org/installer | sudo php
```

可建立指向

```bash
ln -s /usr/local/bin/composer.phar /usr/bin/composer
```

這樣不管在哪個專案只要建立 composer.json 都可以使用了。

### 在 PHP 專案建立 Composer

建立 composer.json

```bash
cd /var/www/html/example
```

composer.json

```json
{
  "require": {
    "monolog/monolog": "1.2.*"
  }
}
```

建立後執行

```bash
composer install
```

專案目錄底下就會產生 vendor 資料夾，裏頭就是在 composer.json 有設定要引入的 library。

Composer 官網也有提供線上的[Library](https://packagist.org/)可以使用。讚!!

### 使用 Github 上的 Repository

把 library 放到 github 上管理，然後再用 composer 引入各自的專案，這豈不是太方便了!!

```bash
vim composer.json
```

```json
{
  "name": "bom-solution",
  "description": "bom solution",
  "homepage": "https://github.com/alanmoment/bom-solution",
  "repositories": [
    {
      "type": "package",
      "package": {
        "name": "alanmoment/bom-solution",
        "version": "v0.1",
        "source": {
          "url": "git@github.com:alanmoment/bom-solution.git",
          "type": "git",
          "reference": "v0.1"
        }
      }
    }
  ],
  "require": {
    "php": ">=5.3.3",
    "alanmoment/bom-solution": "v0.1"
  }
}
```

> 建立 github 的 composer 之前必須先在你的 repository 建立 tag alanmoment 是我的 github 的帳號 bom-solution 是我的 repository v0.1 是我 tag 的版號

存檔後執行

```bash
composer install
```

會發生以下錯誤

```
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Nothing to install or update
Generating autoload files
```

這是因為執行過 composer install 之後目錄底下也會產生一隻 composer.lock 檔案，要再次執行前先把他刪掉，就可以正常執行囉 。

![composer install](https://lh5.googleusercontent.com/-2iiSaEx-0A8/Uchd7p8nS7I/AAAAAAAAADc/qlzt3gnb9tI/w645-h182-no/composer.PNG)

完成囉!!

> Jul 4th, 2013 12:36:00am


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://alanmoment.gitbook.io/moment/php/guan_li_php_library_de_li_qi_composer.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.