诗歌rails之 Generator

关键字: rails generator 来看看怎样写自己的Generator吧
首先运行:

ruby代码

ruby script/generate

ruby script/generate

console中的输出可以看到Rails默认的generate:

ruby代码

Installed Generators
Builtin: controller, integration_test, mailer, migration, model, observer, plugin, resource, scaffold,
scaffold_resource, session_migration, web_service

Installed Generators Builtin: controller, integration_test, mailer, migration, model, observer, plugin, resource, scaffold, scaffold_resource, session_migration, web_service

我们创建本机的generators目录:

ruby代码

mkdir -p ~/.rails/generators/app_layout

mkdir -p ~/.rails/generators/app_layout

或者在某个rails项目里创建私有的generators:

ruby代码

mkdir -p /Users/demo/rails/simple/generators/app_layout

mkdir -p /Users/demo/rails/simple/generators/app_layout

Generators有带参数和不带参数两种，先来看不带参数的Generator:

ruby代码

app_layout
--app_layout_generator.rb
--USAGE
templates
----stylesheet.css
----layout.rhtml

app_layout --app_layout_generator.rb --USAGE templates ----stylesheet.css ----layout.rhtml

我们看看不带参数的Generator的写法:

ruby代码

class AppLayoutGenerator < Rails::Generator::Base
def manifest
record do |m|
m.file "layout.rhtml", "app/views/layouts/application.rhtml"
m.file "stylesheet.css", "public/stylesheets/application.css"
end
end
end

class AppLayoutGenerator < Rails::Generator::Base def manifest record do |m| m.file "layout.rhtml", "app/views/layouts/application.rhtml" m.file "stylesheet.css", "public/stylesheets/application.css" end end end

我们的AppLayoutGenerator继承与Rails::Generator::Base，它的功能相当于cp layout.rhtml和stylesheet.css到后面的文件

我们再运行ruby script/generate看看:

ruby代码

Installed Generators
User: app_layout
Builtin: controller, integration_test, mailer, migration, model, observer, plugin, resource, scaffold,
scaffold_resource, session_migration, web_service

Installed Generators User: app_layout Builtin: controller, integration_test, mailer, migration, model, observer, plugin, resource, scaffold, scaffold_resource, session_migration, web_service

OK，我们看到除了Builtin的Generators，我们刚才创建的本机的app_layout这个Generator也出现在User Generators里

我们这样来使用它:

ruby代码

ruby script/generate app_layout

ruby script/generate app_layout

我们看到console打印出如下信息:

ruby代码

create app/views/layouts/application.rhtml
create public/stylesheets/application.css

 create app/views/layouts/application.rhtml create public/stylesheets/application.css

系统自动创建了上面两个文件，内容为我们的app_layout/templates目录下的两个文件

如果我们想使用ruby script/generate app_layout home这样的方式，用home参数来指定创建home.rhtml和home.css，
我们该怎样写我们的Generator呢?
答案是继承Rails::Generator::NamedBase

ruby代码

class AppLayoutGenerator < Rails::Generator::NamedBase
def manifest
record do |m|
m.template "layout.rhtml", "app/views/layouts/#{file_name}.rhtml"
m.file "stylesheet.css", "public/stylesheets/#{file_name}.css"
end
end
end

class AppLayoutGenerator < Rails::Generator::NamedBase def manifest record do |m| m.template "layout.rhtml", "app/views/layouts/#{file_name}.rhtml" m.file "stylesheet.css", "public/stylesheets/#{file_name}.css" end end end

除了使用m.template，我们还要修改layout.rhtml:

ruby代码

<html>
<head>
<title>Untitled</title>
<%%= stylesheet_link_tag '<%= file_name %>' %>
<%%= javascript_include_tag :defaults %>
</head>
<body>
<div id="container">
<%% flash.each do |name, msg| %>
<%%= content_tag :div, msg, :id => "flash_#{name}" %>
<%% end %>
<%%= yield %>
</div>
</body>
</html>

<html> <head> <title>Untitled</title> <%%= stylesheet_link_tag '<%= file_name %>' %> <%%= javascript_include_tag :defaults %> </head> <body> <div  %> <%% end %> <%%= yield %> </div> </body> </html>

这里的template使用<%% %>而不是<% %>
我们可以看看Rails源码/railties/lib/rails_generator/generators/components/scaffold/templates/layout.html.erb:

ruby代码

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="content-type" content="text/html;charset=UTF-8" />
<title><%= controller_class_name %>: <%%= controller.action_name %></title>
<%%= stylesheet_link_tag 'scaffold' %>
</head>
<body>
<p style="color: green"><%%= flash[:notice] %></p>
<%%= yield %>
</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="content-type" content="text/html;charset=UTF-8" /> <title><%= controller_class_name %>: <%%= controller.action_name %></title> <%%= stylesheet_link_tag 'scaffold' %> </head> <body> <p style="color: green"><%%= flash[:notice] %></p> <%%= yield %> </body> </html>