## bower解决js的依赖管理

[从零开始nodejs系列文章][0],将介绍如何利Javascript做为服务端脚本,通过Nodejs框架web开发。Nodejs框架是基于V8的引擎,是目前速度最快的Javascript引擎。chrome浏览器就基于V8,同时打开20-30个网页都很流畅。Nodejs标准的web开发框架Express,可以帮助我们迅速建立web站点,比起PHP的开发效率更高,而且学习曲线更低。非常适合小型网站,个性化网站,我们自己的Geek网站!!

**关于作者**

* 张丹(Conan), 程序员Java,R,PHP,Javascript
* weibo:@Conan_Z
* blog: [http://blog.fens.me][1]
* email: bsspirit@gmail.com

**转载请注明出处:**
[http://blog.fens.me/nodejs-bower-intro/][2]

[![bower](http://blog.fens.me/wp-content/uploads/2013/08/bower.png)](http://blog.fens.me/wp-content/uploads/2013/08/bower.png)

**前言**
一个新的web项目开始,我们总是很自然地去下载需要用到的js类库文件,比如jQuery,去官网下载名为jquery-1.10.2.min.js文件,放到我们的项目里。当项目又需要bootstrap的时候,我们会重复刚才的工作,去bootstrap官网下载对应的类库。如果bootstrap所依赖的jQuery并不是1.10.2,而是2.0.3时,我们会再重新下载一个对应版本的jQuery替换原来的。

包管理是个复杂的问题,我们要知道谁依赖谁,还要明确哪个版本依赖哪个版本。这些对于开发人员来说,负担过重了。bower作为一个js依赖管理的工具,提供一种理想包管理方式,借助了npm的一些思想,为我们提供一个舒服的开发环境。

你要还不动起手来试试bower,那你一定不会知道,前端开发是件多么享受的事。

**目录**

1. bower介绍
1. bower安装
1. bower命令
1. bower使用
1. 用bower提交自己类库

## 1. bower介绍

Bower 是 twitter 推出的一款包管理工具,基于nodejs的模块化思想,把功能分散到各个模块中,让模块和模块之间存在联系,通过 Bower 来管理模块间的这种联系。

包管理工具一般有以下的功能:

* 注册机制:每个包需要确定一个唯一的 ID 使得搜索和下载的时候能够正确匹配,所以包管理工具需要维护注册信息,可以依赖其他平台。
* 文件存储:确定文件存放的位置,下载的时候可以找到,当然这个地址在网络上是可访问的。
* 上传下载:这是工具的主要功能,能提高包使用的便利性。比如想用 jquery 只需要 install 一下就可以了,不用到处找下载。上传并不是必备的,根据文件存储的位置而定,但需要有一定的机制保障。
* 依赖分析:这也是包管理工具主要解决的问题之一,既然包之间是有联系的,那么下载的时候就需要处理他们之间的依赖。下载一个包的时候也需要下载依赖的包。

功能介绍,摘自文章:[http://chuo.me/2013/02/twitter-bower.html][3]

## 2. bower安装

bower插件是通过npm, Node.js包管理器安装和管理的.

**我的系统环境**

* win7 64bit
* Nodejs:v0.10.5
* Npm:1.2.19

~ D:\workspace\javascript>node -v
v0.10.5

~ D:\workspace\javascript>npm -v
1.2.19

在系统中,我们已经安装好了Nodejs和npm。win7安装nodejs请参考文章:[Nodejs开发框架Express3.0开发手记–从零开始][4]

**安装bower**
全局安装bower

~ D:\workspace\javascript>npm install bower -g

新建一个express3的项目nodejs-bower

~ D:\workspace\javascript>express -e nodejs-bower
~ D:\workspace\javascript>cd nodejs-bower && npm install

## 3. bower命令

bower安装后,我们就可以用bower这个命令了。

~ D:\workspace\javascript\nodejs-bower>bower
Usage:
bower [] []
Commands:
cache Manage bower cache
help Display help information about Bower
home Opens a package homepage into your favorite browser
info Info of a particular package
init Interactively create a bower.json file
install Install a package locally
link Symlink a package folder
list List local packages
lookup Look up a package URL by name
prune Removes local extraneous packages
register Register a package
search Search for a package by name
update Update a local package
uninstall Remove a local package
Options:
-f, –force Makes various commands more forceful
-j, –json Output consumable JSON
-l, –log-level What level of logs to report
-o, –offline Do not hit the network
-q, –quiet Only output important information
-s, –silent Do not output anything, besides errors
-V, –verbose Makes output more verbose
–allow-root Allows running commands as root
See ‘bower help ‘ for more information on a specific command.

Commands,列出了bower支持的各种命令。

* cache:bower缓存管理
* help:显示Bower命令的帮助信息
* home:通过浏览器打开一个包的github发布页
* info:查看包的信息
* init:创建bower.json文件
* install:安装包到项目
* link:在本地bower库建立一个项目链接
* list:列出项目已安装的包
* lookup:根据包名查询包的URL
* prune:删除项目无关的包
* register:注册一个包
* search:搜索包
* update:更新项目的包
* uninstall:删除项目的包

## 4. bower使用

**1). 安装jQuery到项目nodejs-bower**

~ D:\workspace\javascript\nodejs-bower>bower install jquery
bower jquery#* not-cached git://github.com/components/jquery.git#*
bower jquery#* resolve git://github.com/components/jquery.git#*
bower jquery#* download https://github.com/components/jquery/archive/2.0.3.tar.gz
bower jquery#* extract archive.tar.gz
bower jquery#* resolved git://github.com/components/jquery.git#2.0.3
bower jquery#~2.0.3 install jquery#2.0.3

jquery#2.0.3 bower_components\jquery

通过执行命令,我们可以看到jQuery的最新版本被下载,并安装到项目的bower_components\jquery目录

查看bower_components/jquery目录,发现了3个文件。

~ D:\workspace\javascript\nodejs-bower>ls bower_components/jquery -a
. .. .bower.json component.json jquery.js

同样地,我们的项目还需要d3的类库

~ D:\workspace\javascript\nodejs-bower>bower install d3
bower d3#* not-cached git://github.com/mbostock/d3.git#*
bower d3#* resolve git://github.com/mbostock/d3.git#*
bower d3#* download https://github.com/mbostock/d3/archive/v3.2.8.tar.gz
bower d3#* extract archive.tar.gz
bower d3#* resolved git://github.com/mbostock/d3.git#3.2.8
bower d3#~3.2.8 install d3#3.2.8

d3#3.2.8 bower_components\d3

非常方便,下载并安装完成!

**2). 查看项目中已导入的类库**

~ D:\workspace\javascript\nodejs-bower>bower list
bower check-new Checking for new versions of the project dependencies..
nodejs-bower#0.0.0 D:\workspace\javascript\nodejs-bower
├── d3#3.2.8
└── jquery#2.0.3

**3). 安装bootstrap库,并查看依赖情况**

~ D:\workspace\javascript\nodejs-bower>bower install bootstrap
bower bootstrap#* cached git://github.com/twbs/bootstrap.git#3.0.0-rc1
bower bootstrap#* validate 3.0.0-rc1 against git://github.com/twbs/bootstrap.git#*
bower jquery#>= 1.9.0 cached git://github.com/components/jquery.git#2.0.3
bower jquery#>= 1.9.0 validate 2.0.3 against git://github.com/components/jquery.git#>= 1.9.0
bower bootstrap#~3.0.0-rc1 install bootstrap#3.0.0-rc1

bootstrap#3.0.0-rc1 bower_components\bootstrap
└── jquery#2.0.3

~ D:\workspace\javascript\nodejs-bower>bower list
bower check-new Checking for new versions of the project dependencies..
nodejs-bower#0.0.0 D:\workspace\javascript\nodejs-bower
├─┬ bootstrap#3.0.0-rc1 extraneous
│ └── jquery#2.0.3
├── d3#3.2.8
└── jquery#2.0.3

我们发现bootstrap,对jquery是有依赖的。

**4). 删除jQuery库,破坏依赖关系**

~ D:\workspace\javascript\nodejs-bower>bower uninstall jquery
bower conflict bootstrap depends on jquery
Continue anyway? (y/n) y
bower uninstall jquery

~ D:\workspace\javascript\nodejs-bower>bower list
bower check-new Checking for new versions of the project dependencies..
nodejs-bower#0.0.0 D:\workspace\javascript\nodejs-bower
├─┬ bootstrap#3.0.0-rc1 extraneous
│ └── jquery missing
├── d3#3.2.8
└── jquery missing

**5). 安装低版本的jQuery,制造不版本兼容**

~ D:\workspace\javascript\nodejs-bower>bower install jquery#1.7.2
bower jquery#~2.0.3 cached git://github.com/components/jquery.git#2.0.3
bower jquery#~2.0.3 validate 2.0.3 against git://github.com/components/jquery.git#~2.0.3
bower jquery#>= 1.9.0 cached git://github.com/components/jquery.git#2.0.3
bower jquery#>= 1.9.0 validate 2.0.3 against git://github.com/components/jquery.git#>= 1.9.0
bower jquery#1.7.2 cached git://github.com/components/jquery.git#1.7.2
bower jquery#1.7.2 validate 1.7.2 against git://github.com/components/jquery.git#1.7.2

Unable to find a suitable version for jquery, please choose one:
1) jquery#1.7.2 which resolved to 1.7.2
2) jquery#~2.0.3 which resolved to 2.0.3 and has nodejs-bower as dependants
3) jquery#>= 1.9.0 which resolved to 2.0.3 and has bootstrap#3.0.0-rc1 as dependants

Prefix the choice with ! to persist it to bower.json

Choice: 1
bower jquery#1.7.2 install jquery#1.7.2

jquery#1.7.2 bower_components\jquery

~ D:\workspace\javascript\nodejs-bower>bower list
bower check-new Checking for new versions of the project dependencies..
nodejs-bower#0.0.0 D:\workspace\javascript\nodejs-bower
├─┬ bootstrap#3.0.0-rc1 extraneous
│ └── jquery#1.7.2 incompatible with >= 1.9.0 (2.0.3 available)
├── d3#3.2.8
└── jquery#1.7.2 incompatible with ~2.0.3 (2.0.3 available)

我们可以清楚的看到bower,很明确的告诉了我们,jquery和bootstrap是不兼容的,强大之处大家应该有所体会。

**6).升级jQuery,让版本兼容**

~ D:\workspace\javascript\nodejs-bower>bower update jquery
bower jquery#~2.0.3 cached git://github.com/components/jquery.git#2.0.3
bower jquery#~2.0.3 validate 2.0.3 against git://github.com/components/jquery.git#~2.0.3
bower jquery#>= 1.9.0 cached git://github.com/components/jquery.git#2.0.3
bower jquery#>= 1.9.0 validate 2.0.3 against git://github.com/components/jquery.git#>= 1.9.0
bower jquery#~2.0.3 install jquery#2.0.3

jquery#2.0.3 bower_components\jquery

~ D:\workspace\javascript\nodejs-bower>bower list
bower check-new Checking for new versions of the project dependencies..
nodejs-bower#0.0.0 D:\workspace\javascript\nodejs-bower
├─┬ bootstrap#3.0.0-rc1 extraneous
│ └── jquery#2.0.3
├── d3#3.2.8
└── jquery#2.0.3

多么智能,一键搞定,这才是高效的开发。

**7). 查看本地bower已经缓存的类库**

~ D:\workspace\javascript\nodejs-bower>bower cache list
bootstrap=git://github.com/twbs/bootstrap.git#3.0.0-rc1
d3=git://github.com/mbostock/d3.git#3.2.8
jquery=git://github.com/components/jquery.git#1.7.2
jquery=git://github.com/components/jquery.git#2.0.3

**8). 查看D3库信息**

~ D:\workspace\javascript\nodejs-bower>bower info d3
d3

Versions:
– 3.2.8
– 3.2.7
– 3.2.6
– 3.2.5
– 3.2.4
– 3.2.3

**9). 查看dojo库的url**

~ D:\workspace\javascript\nodejs-bower>bower lookup dojo
dojo git://github.com/dojo/dojo.git

**10). 用浏览器打开dojo的发布主页**

~ D:\workspace\javascript\nodejs-bower>bower home dojo
bower dojo#* not-cached git://github.com/dojo/dojo.git#*
bower dojo#* resolve git://github.com/dojo/dojo.git#*
bower dojo#* download https://github.com/dojo/dojo/archive/1.9.1.tar.gz
bower dojo#* extract archive.tar.gz
bower dojo#* resolved git://github.com/dojo/dojo.git#1.9.1

浏览器自动打开:https://github.com/dojo/dojo

**11). 查询包含dojo的类库**

~ D:\workspace\javascript\nodejs-bower>bower search dojo
Search results:

dojo git://github.com/dojo/dojo.git
dojox git://github.com/dojo/dojox.git
dojo-util git://github.com/dojo/util.git
dojo-bootstrap git://github.com/samvdb/Dojo-Bootstrap

真是方便实用的技术。

## 5. 用bower提交自己类库

**1). 生成bower.json配置文件**

~ D:\workspace\javascript\nodejs-bower>bower init
bower existing The existing bower.json file will be used and filled in
[?] name: nodejs-bower
[?] version: 0.0.0
[?] main file:
[?] set currently installed components as dependencies? No
[?] add commonly ignored files to ignore list? Yes

查看生成的文件bower.json

{
“name”: “nodejs-bower”,
“version”: “0.0.0”,
“ignore”: [
“**/.*”,
“node_modules”,
“bower_components”,
“test”,
“tests”
],
“dependencies”: {
“d3”: “git://github.com/mbostock/d3.git#~3.2.8”,
“jquery”: “git://github.com/components/jquery.git#~2.0.3”
}
}

**2). 在github创建一个资源库:nodejs-bower**
**3). 本地工程绑定github**

~ D:\workspace\javascript\nodejs-bower>git init
Initialized empty Git repository in D:/workspace/javascript/nodejs-bower/.git/

~ D:\workspace\javascript\nodejs-bower>git add .
~ D:\workspace\javascript\nodejs-bower>git commit -m “first commit”
# On branch master
#
# Initial commit
#
# Untracked files:
# (use “git add …” to include in what will be committed)
#
# app.js
# bower.json
# bower_components/
# node_modules/
# package.json
# public/
# routes/
# views/
nothing added to commit but untracked files present (use “git add” to track)

~ D:\workspace\javascript\nodejs-bower>git remote add origin https://github.com/bsspirit/nodejs-bower

~ D:\workspace\javascript\nodejs-bower>git push -u origin master
Counting objects: 565, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (516/516), done.
Writing objects: 100% (565/565), 803.08 KiB, done.
Total 565 (delta 26), reused 0 (delta 0)
To https://github.com/bsspirit/nodejs-bower
* [new branch] master -> master
Branch master set up to track remote branch master from origin.

**4). 注册到bower官方类库**

~ D:\workspace\javascript\nodejs-bower>bower register nodejs-bower git@github.com:bsspirit/nodejs-bower.git
bower convert Converted git@github.com:bsspirit/nodejs-bower.git to git://github.com/bsspirit/n
odejs-bower.git
bower nodejs-bower#* resolve git://github.com/bsspirit/nodejs-bower.git#*
bower nodejs-bower#* checkout master
bower nodejs-bower#* resolved git://github.com/bsspirit/nodejs-bower.git#af3ceaac07
Registering a package will make it visible and installable via the registry (https://bower.herokuapp.com), continue? (y/
n) y
bower nodejs-bower register git://github.com/bsspirit/nodejs-bower.git

Package nodejs-bower registered successfully!
All valid semver tags on git://github.com/bsspirit/nodejs-bower.git will be available as versions.
To publish a new version, you just need release a valid semver tag.

Run bower info nodejs-bower to list the package versions.

**5). 查询我们自己的包**

D:\workspace\javascript\nodejs-bower>bower search nodejs-bower
Search results:

nodejs-bower git://github.com/bsspirit/nodejs-bower.git

**6). 安装我们自己的包**

D:\workspace\javascript\nodejs-bower>bower install nodejs-bower
bower nodejs-bower#* cached git://github.com/bsspirit/nodejs-bower.git#af3ceaac07
bower nodejs-bower#* validate af3ceaac07 against git://github.com/bsspirit/nodejs-bower.git#*
bower nodejs-bower#* install nodejs-bower#af3ceaac07

nodejs-bower#af3ceaac07 bower_components\nodejs-bower
├── d3#3.2.8
└── jquery#2.0.3

其实模块化,版本依赖,开发类库,发布类库,安装类库,都是一条命令!还能再简单一点么!快把项目模块化,然后分享给大家吧!!未来是属于开发者的。

**转载请注明出处:**
[http://blog.fens.me/nodejs-bower-intro/][2]

This entry was posted in [Javascript语言实践][5]

[0]: http://blog.fens.me/series-nodejs/
[1]: http://blog.fens.me/
[2]: http://blog.fens.me/nodejs-bower-intro/
[3]: http://chuo.me/2013/02/twitter-bower.html
[4]: http://blog.fens.me/nodejs-express3/
[5]: http://blog.fens.me/category/javascript%25e8%25af%25ad%25e8%25a8%2580%25e5%25ae%259e%25e8%25b7%25b5/