常用GEM的使用方法
1. kaminari 分页系统
1.1
gem 'kaminari'
bundle
rails g kaminari:config
rails g kaminari:views default/bootstrap3
1.2
lists_controller.rb
defindex@lists=List.all.order(created_at::desc).page(params[:page]).per(5)end
1.3
<%= paginate @lists %>
1.4
en: hello: "Hello world" views: pagination: first: "首页" last: "末页" previous: "上一页" next: "下一页" truncate: "..."
2. devise 用户登陆注册系统
2.1
gem devise
bundle
rails g devise:install
rails g devise User
rails g devise:views
3. cancancan
3.1
gem 'cancancan'
bundle
rails g cancan:ability
ability.rbifuser.admin?can:manage,:allelseend
4. redcarpet 文本支持 markdown
gem 'redcarpet'
bundle
接下来，打开app/helper/application_helper.rb， 添加下列代码。defmarkdown(text)options={:autolink=>true,:space_after_headers=>true,:fenced_code_blocks=>true,:no_intra_emphasis=>true,:hard_wrap=>true,:strikethrough=>true}markdown=Redcarpet::Markdown.new(HTMLwithCodeRay,options)markdown.render(h(text)).html_safeendclassHTMLwithCodeRay<Redcarpet::Render::HTMLdefblock_code(code,language)CodeRay.scan(code,language).div(:tab_width=>2)endend
5. carrierwave 图片上传
gem 'carrierwave', '0.6.2'
gem 'mini_magick' #不使用rmagick，占内存
bundle
rails g migration add_avatar_to_users avatar:string
rake db:migrate
rails generate uploader Avatar [将会生成文件app/uploaders/avatar_uploader.rb]
mount_uploader :avatar, AvatarUploader [为user的model user.rb添加如下代码，使表之间关联]
修改app/uploaders/avatar_uploader.rb
如何在表单中上传<%=form_for(@user)do|f|%><divclass="field"> <%= f.file_field :avatar %>
<%= f.hidden_field :avatar_cache %>
</div>...
如何显示图片<%=image_tag(@user.avatar_url(:large))if@user.avatar%>[这里的:large就是指定图片的版本为large64x64大小]
6. bootstrap-sass
gem 'bootstrap-sass'
bundle
往 assets 里的 css 和 js 添加 引用
重新 rails s
7. simple_form
gem 'simple_form'
bundle
rails g simple_form:install
