在第一篇分析我们曾经举例,创建一个新工程,
cordova create hello hellotest com.xxx.hellotest
cli.js文件分析命令行参数后,会走到
else if (cmd == 'create' || cmd == 'serve') {
cordova[cmd].apply(this, tokens);
}
将会执行create函数
create.js
var path = require('path'),
fs = require('fs'),
shell = require('shelljs'),
platforms = require('../platforms'),
help = require('./help'),
events = require('./events'),
config = require('./config'),
lazy_load = require('./lazy_load'),
util = require('./util'); var DEFAULT_NAME = "HelloCordova",
DEFAULT_ID = "io.cordova.hellocordova"; /**
* Usage:
* create(dir) - creates in the specified directory
* create(dir, name) - as above, but with specified name
* create(dir, id, name) - you get the gist
**/
module.exports = function create (dir, id, name, callback) {
var options = []; if (arguments.length === 0) {
return help();//src/help.js 读取doc/help.txt内容,在终端显示帮助信息
} // Massage parameters
var args = Array.prototype.slice.call(arguments, 0);
//arguments不是数组,但是可以通过arguments.length取到长度
//Array.prototype.slice.call(arguments,0)就类似于arguments.slice(0),
//但因为arguments不是真正的Array,所以它没有slice这个方法.能用slice方法的,只要有length属性就行。
//Array.prototype已经被call改成arguments了,因为满足slice执行的条件(有length属性),所以没有报错。
//简单说作用就是:把arguments这个伪数组转换为真正的数组
if (typeof args[args.length-1] == 'function') {
callback = args.pop();
} else if (typeof callback !== 'function') {
callback = undefined;
}
//判断是否有回调函数 if (args.length === 0) {
dir = process.cwd();//获得当前路径
id = DEFAULT_ID;
name = DEFAULT_NAME;
} else if (args.length == 1) {
id = DEFAULT_ID;
name = DEFAULT_NAME;
} else if (args.length == 2) {
name = DEFAULT_NAME;
} else {
dir = args.shift();//shift() 方法用于把数组的第一个元素从其中删除,并返回第一个元素的值
id = args.shift();
name = args.shift();
options = args;
} // Make absolute.
dir = path.resolve(dir); events.emit('log', 'Creating a new cordova project with name "' + name + '" and id "' + id + '" at location "' + dir + '"'); var dotCordova = path.join(dir, '.cordova');
var www_dir = path.join(dir, 'www'); // Create basic project structure.
shell.mkdir('-p', dotCordova);
shell.mkdir('-p', path.join(dir, 'platforms'));
shell.mkdir('-p', path.join(dir, 'merges'));
shell.mkdir('-p', path.join(dir, 'plugins'));
shell.mkdir('-p', www_dir);
var hooks = path.join(dotCordova, 'hooks');
shell.mkdir('-p', hooks);
//创建一系列工作目录
//当前dir/.cordova , dir/www , dir/platforms, dir/merges ,dir/plugins ,dir/.cordova/hooks // Add directories for hooks
shell.mkdir(path.join(hooks, 'after_build'));
shell.mkdir(path.join(hooks, 'after_compile'));
shell.mkdir(path.join(hooks, 'after_docs'));
shell.mkdir(path.join(hooks, 'after_emulate'));
shell.mkdir(path.join(hooks, 'after_platform_add'));
shell.mkdir(path.join(hooks, 'after_platform_rm'));
shell.mkdir(path.join(hooks, 'after_platform_ls'));
shell.mkdir(path.join(hooks, 'after_plugin_add'));
shell.mkdir(path.join(hooks, 'after_plugin_ls'));
shell.mkdir(path.join(hooks, 'after_plugin_rm'));
shell.mkdir(path.join(hooks, 'after_prepare'));
shell.mkdir(path.join(hooks, 'after_run'));
shell.mkdir(path.join(hooks, 'before_build'));
shell.mkdir(path.join(hooks, 'before_compile'));
shell.mkdir(path.join(hooks, 'before_docs'));
shell.mkdir(path.join(hooks, 'before_emulate'));
shell.mkdir(path.join(hooks, 'before_platform_add'));
shell.mkdir(path.join(hooks, 'before_platform_rm'));
shell.mkdir(path.join(hooks, 'before_platform_ls'));
shell.mkdir(path.join(hooks, 'before_plugin_add'));
shell.mkdir(path.join(hooks, 'before_plugin_ls'));
shell.mkdir(path.join(hooks, 'before_plugin_rm'));
shell.mkdir(path.join(hooks, 'before_prepare'));
shell.mkdir(path.join(hooks, 'before_run')); // Write out .cordova/config.json file with a simple json manifest
//使用指定id和name参数写入config.json
require('../cordova').config(dir, {
id:id,
name:name
}); var config_json = config.read(dir);
//读取.cordova/config.json //finalize函数作用:判断下载的tar包是否完整,删除原有www目录下内容,拷贝新内容到www目录,添加配置文件
var finalize = function(www_lib) {
while (!fs.existsSync(path.join(www_lib, 'index.html'))) {
www_lib = path.join(www_lib, 'www');
if (!fs.existsSync(www_lib)) {
var err = new Error('downloaded www assets in ' + www_lib + ' does not contain index.html, or www subdir with index.html');
if (callback) return callback(err);
else throw err;
}
}
//删除当前www目录下所以文件
shell.cp('-rf', path.join(www_lib, '*'), www_dir);
var configPath = util.projectConfig(dir);
//获得config.xml路径 www/config.xml // Add template config.xml for apps that are missing it
if (!fs.existsSync(configPath)) {
var template_config_xml = path.join(__dirname, '..', 'templates', 'config.xml');
shell.cp(template_config_xml, www_dir);
}
//如果config.xml不存在,从cli模板目录拷贝此文件到当前应用目录 // Write out id and name to config.xml id和name写入config.xml
var config = new util.config_parser(configPath);
config.packageName(id);
config.name(name);
if (callback) callback();
}; // Check if www assets to use was overridden.
if (config_json.lib && config_json.lib.www) {
//判断config.josn的lib和www字段是否为空
events.emit('log', 'Using custom www assets ('+config_json.lib.www.id+').');
//下载config.json中uri地址的hello-world文件包
lazy_load.custom(config_json.lib.www.uri, config_json.lib.www.id, 'www', config_json.lib.www.version, function(err) {
if (err) {
if (callback) callback(err);
else throw err;
} else {
events.emit('log', 'Copying custom www assets into "' + www_dir + '"');
//下载成功后拷贝到指定目录
finalize(path.join(util.libDirectory, 'www', config_json.lib.www.id, config_json.lib.www.version));
}
});
} else {
// Nope, so use stock cordova-hello-world-app one.
events.emit('log', 'Using stock cordova hello-world application.');
//根据platform.js中参数下载默认文件
lazy_load.cordova('www', function(err) {
if (err) {
if (callback) callback(err);
else throw err;
} else {
events.emit('log', 'Copying stock Cordova www assets into "' + www_dir + '"');
finalize(path.join(util.libDirectory, 'www', 'cordova', platforms.www.version));
}
});
}
};
1)参数解析,创建工作目录:参数存在情况下,按照dir, id, name,这几个参数指定内容创建目录,并将id和name参数写入config.json文件。
hello/
|--.cordova/
| | -- hooks/
| | -- config.json
|-- merges/
|-- www/
| `-- config.xml
|-- platforms/
`-- plugins/
在.cordova/hooks目录下创建了很多以事件名称命名的目录,如after_build ,after_compile等,在这些目录下,用户可以添加自定义文件,当这些系统事件发生时,这些目录下的文件相当于回调函数,会被执行
这部分还涉及到config.js文件,其中定义了对config.json文件读写操作的函数
2)判断config.josn的lib和www字段是否为空,非空时,按照.cordova/config_json中指定的参数下载默认的web页面部分文件(即www目录下内容),下载成功后会调用finalize函数,该函数会删除原www目录下文件,拷贝下载的文件到www目录。
3)lazy_load 函数是提供下载功能的接口文件(见src/lazy_load.js),主要包含两个函数
lazy_load.cordova
lazy_load.custom
lazy_load.js
module.exports = {
cordova:function lazy_load(platform, callback) {
if (!(platform in platforms)) {
var err = new Error('Cordova library "' + platform + '" not recognized.');
if (callback) return callback(err);
else throw err;
} var url = platforms[platform].url + ';a=snapshot;h=' + platforms[platform].version + ';sf=tgz';
module.exports.custom(url, 'cordova', platform, platforms[platform].version, function(err) {
if (err) {
if (callback) return callback(err);
else throw err;
} else {
if (callback) callback();
}
});
},
custom:function(url, id, platform, version, callback) {
var download_dir = (platform == 'wp7' || platform == 'wp8' ? path.join(util.libDirectory, 'wp', id, version) :
path.join(util.libDirectory, platform, id, version));
if (fs.existsSync(download_dir)) {
events.emit('log', id + ' library for "' + platform + '" already exists. No need to download. Continuing.');
if (callback) return callback();
}
hooker.fire('before_library_download', {
platform:platform,
url:url,
id:id,
version:version
}, function() {
var uri = URL.parse(url);
if (uri.protocol && uri.protocol[1] != ':') { // second part of conditional is for awesome windows support. fuuu windows
npm.load(function() {
// Check if NPM proxy settings are set. If so, include them in the request() call.
var proxy;
if (uri.protocol == 'https:') {
proxy = npm.config.get('https-proxy');
} else if (uri.protocol == 'http:') {
proxy = npm.config.get('proxy');
} shell.mkdir('-p', download_dir);
var size = 0;
var request_options = {uri:url};
if (proxy) {
request_options.proxy = proxy;
}
events.emit('log', 'Requesting ' + JSON.stringify(request_options) + '...');
request.get(request_options, function(err, req, body) { size = body.length; })
.pipe(zlib.createUnzip())
.pipe(tar.Extract({path:download_dir}))
.on('error', function(err) {
shell.rm('-rf', download_dir);
if (callback) callback(err);
else throw err;
})
.on('end', function() {
events.emit('log', 'Downloaded, unzipped and extracted ' + size + ' byte response.');
var entries = fs.readdirSync(download_dir);
var entry = path.join(download_dir, entries[0]);
shell.mv('-f', path.join(entry, (platform=='blackberry10'?'blackberry10':''), '*'), download_dir);
shell.rm('-rf', entry);
hooker.fire('after_library_download', {
platform:platform,
url:url,
id:id,
version:version,
path:download_dir,
size:size,
symlink:false
}, function() {
if (callback) callback();
});
});
});
} else {
// local path
// symlink instead of copying
fs.symlinkSync((uri.protocol && uri.protocol[1] == ':' ? uri.href : uri.path), download_dir, 'dir');
hooker.fire('after_library_download', {
platform:platform,
url:url,
id:id,
version:version,
path:download_dir,
symlink:true
}, function() {
if (callback) callback();
});
}
});
},
based_on_config:function(project_root, platform, callback) {
var custom_path = config.has_custom_path(project_root, platform);
if (custom_path) {
var dot_file = config.read(project_root);
module.exports.custom(dot_file.lib[platform].uri, dot_file.lib[platform].id, platform, dot_file.lib[platform].version, callback);
} else {
module.exports.cordova(platform, callback);
}
}
};
lazy_load.cordova首先查找传入的platform参数是否在顶层目录下platforms.js文件中的对象参数中是否存在;
platforms.js
module.exports = {
'ios' : {
parser : require('./src/metadata/ios_parser'),
url : 'https://git-wip-us.apache.org/repos/asf?p=cordova-ios.git',
version: '3.0.0'
},
'android' : {
parser : require('./src/metadata/android_parser'),
url : 'https://git-wip-us.apache.org/repos/asf?p=cordova-android.git',
version: '3.0.0'
},
'wp7' : {
parser : require('./src/metadata/wp7_parser'),
url : 'https://git-wip-us.apache.org/repos/asf?p=cordova-wp8.git',
version: '3.0.0'
},
'wp8' : {
parser : require('./src/metadata/wp8_parser'),
url : 'https://git-wip-us.apache.org/repos/asf?p=cordova-wp8.git',
version: '3.0.0'
},
blackberry10 : {
parser : require('./src/metadata/blackberry10_parser'),
url : 'https://git-wip-us.apache.org/repos/asf?p=cordova-blackberry.git',
version: '3.0.0'
},
'www':{
url : 'https://git-wip-us.apache.org/repos/asf?p=cordova-app-hello-world.git',
version: '3.0.0'
}
};
platforms.js中列出了所有cordova支持的平台,每个平台包括三个参数:
parser : 解析平台配置参数的解析文件位置;
url : 源码存在的git路径
version:版本号
lazy_load.cordova会按照传入参数在这个表中找到对应url下载文件。
lazy_load.custom与lazy_load.cordova不同之处是,从.cordova/config_json中指定的url参数下载文件
shelljs,create函数中多次用到shelljs,它是一个可移植的类似unix shell的命令行工具,支持Windows/Linux/OS X,详见https://npmjs.org/package/shelljs