为你的Rails网站添加OpenSearch功能

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如果你是用过Google的搜索条，就会知道，它会根据你的输入实时的列出相关的搜索项目。让我们在自己的 Rails 网站里也添加这一功能。

1. 新建application

    创建一个 controller images，它包含三个 action。再创建一个 model image，要有个字段为 filename。

ruby 代码

rails searchdemo
cd searchdemo
ruby script/generate controller images index suggest you_choose
ruby script/generate model image

2. search.xml

  在 public 目录下创建 search.xml。 URL-TO-AN-ICON-FILE要换成你自己网站icon文件的URL。 YOUR-ADDRESS换成你自己的网址。

xml 代码

xml   version = "1.0"   encoding = "UTF-8" ?>
< OpenSearchDescription   xmlns = "http://a9.com/-/spec/opensearch/1.1/"
                       xmlns:moz = "http://www.mozilla.org/2006/browser/search/" >
    < ShortName > Image Search ShortName >
    < Description > Image Search Description >
    < InputEncoding > UTF-8 InputEncoding >
    < Image   height = "16"   width = "16"   type = "image/x-icon" > URL-TO-AN-ICON-FILE Image >
    < Url   type = "application/x-suggestions+json"   template = "http://YOUR-ADDRESS/images/suggest?filename={searchTerms}" />
    < Url   type = "text/html"   method = "GET"   template = "http://YOUR-ADDRESS/images/you_choose/{searchTerms}" />
OpenSearchDescription >

3. Controller
     rhtml 的内用就省略了。

ruby 代码

def  suggest
  headers["Content-Type" ] =  "application/x-suggestions+json"
  codes = Image.find(:all , :conditions =>[ "filename LIKE ?" ,params[ :filename ]+ "%" ], :limit =>10, :group => "filename" , :order => "filename" )
  @res  = codes.map{  |c | c.filename }
  render  :text  => [params[ :filename ],  @res ].to_json
end

def  you_choose
  @image_pages ,  @images  = paginate  :images ,  :per_page  => 20,
                                   :order  => 'filename',
                                  :conditions  => [ "filename LIKE ?" ,params[ :filename ]+ "%" ]
end

4. Settings
    layouts/images.rhtml 文件中，追加下面的 link。

xml 代码

< link   rel = "search"   type = "application/opensearchdescription+xml"   title = "Search a Image"   href = "http://YOUR-ADDRESS/search.xml"   />

    routes.rb 里，追加下边的映射。

ruby 代码

map.connect ' :controller / :action '

5. 进阶
    想上边那样设定的话，已经为网站追加了OpenSearch功能。可是当测试网址和实际网址不同的时候，xml 文件里的静态URL就需要修改。让我们用 url_for 将它改进。
    追加一个 action opensearch。

ruby 代码

def  opensearch
  headers["Content-Type" ] =  "application/opensearchdescription+xml; charset=utf-8"
  render :layout  =>  false
end

    opensearch.rhtml （当然，search.xml要删除）

xml 代码

< OpenSearchDescription   xmlns = "http://a9.com/-/spec/opensearch/1.1/"
                       xmlns:moz = "http://www.mozilla.org/2006/browser/search/" >
< ShortName > Image Search ShortName >
< Description > Image Search Description >
< InputEncoding > UTF-8 InputEncoding >
< Image   height = "16"   width = "16"   type = "image/x-icon" > < %= @request.protocol + @request.host_with_port % > /images/image.ico Image >
< Url   type = "text/html"   method = "get"   template = "<%= url_for :only_path => false, :controller => 'images', :action => 'you_choose' %>" >
  < Param   name = "filename"   value = "{searchTerms}" />
Url >
< moz:SearchForm > < %= url_for  :only_path  = >  false,  :action  = >  'list',  :controller  = >  'images' % > moz:SearchForm >
< Url   type = "application/x-suggestions+json"   template = "<%= url_for :only_path => false, :action => 'suggest', :controller => 'images' %>?filename={searchTerms}" />
OpenSearchDescription >

    layouts/images.rhtml 文件中的 link 也要修改。

xml 代码

< link   rel = "search"   type = "application/opensearchdescription+xml"   title = "Search a Image"   href = "<%= url_for :only_path => false, :controller => 'images', :action => 'opensearch' %>"   >