Ruby on rails 从rake任务渲染视图（带有部分视图）

我在rake任务中获得了以下代码：

class PdfExporter < ActionView::Base
  include Rails.application.routes.url_helpers
  include ActionView::Helpers::TagHelper
  include ActionView::Helpers::UrlHelper

  def generate_pdf_from_html  
    content = File.read('path/to/view.html.erb')
    erb = ERB.new(content)
    html_content = erb.result(binding)

    # ... some pdf stuff
  end
end

---

是空的。这可能意味着ActionView“不知道”在哪里搜索视图。

下面是我的一个rake任务示例，它从视图创建html文件。为了让它工作，您必须通过覆盖一些默认值并传入一个假控制器和请求来安抚ActionView：

  desc 'Example of writing a view to a file'
  task :example => :environment do

    # View that works with Rake
    class RakeActionView < ActionView::Base
      include Rails.application.routes.url_helpers
      include ::ApplicationHelper
      # Include other helpers that you will use

      # Make sure this matches the expected environment, e.g. localhost for dev
      # and full domain for prod
      def default_url_options
        {host: 'localhost:3000'}
      end

      # It is safe to assume that the rake request is legit
      def protect_against_forgery?
        false
      end
    end

    # build a simple controller to process the view
    controller = ActionController::Base.new
    controller.class_eval do
      include Rails.application.routes.url_helpers
      include ::ApplicationHelper
    end

    # build a fake request
    controller.request = ActionDispatch::TestRequest.new

    # build the rake view with the path to the app views
    view = RakeActionView.new(Rails.root.join('app', 'views'), {}, controller)

    # example assigning instance @variables to the view
    view.assign( :user => User.first )

    # Render the view to html
    html = view.render(template: 'relative/path/to/template', layout: 'layouts/example')

    # Write html to temp file and then copy to destination
    temp = Tempfile.new('example_file')
    temp.write(html)
    FileUtils.cp( temp.path, 'path/to/exmple_file' )

    # optionally set permissions on file
    File.chmod(0774, 'path/to/exmple_file')

    # close up the temp file
    temp.close
    temp.unlink
  end

desc'将视图写入文件的示例'
任务：示例=>：环境do
#使用Rake的视图
类RakeActionViewuser.first）
#将视图呈现为html
html=view.render（模板：'relative/path/to/template'，布局：'layouts/example'）
#将html写入临时文件，然后复制到目标
temp=Tempfile.new（'example_file'）
临时写入（html）
cp（temp.path，“path/to/example\u文件”）
#可以选择设置文件的权限
chmod（0774，'path/to/example\u File'）
#关闭临时文件
临时关闭
临时取消链接
结束

---

看起来您遇到的问题已由

RakeActionView.new（Rails.root.join（'app'，'views'），{}，controller）

修复，它设置了ActionView查找模板的路径。

您是否尝试过绝对路径，如

？

Searched in:

  desc 'Example of writing a view to a file'
  task :example => :environment do

    # View that works with Rake
    class RakeActionView < ActionView::Base
      include Rails.application.routes.url_helpers
      include ::ApplicationHelper
      # Include other helpers that you will use

      # Make sure this matches the expected environment, e.g. localhost for dev
      # and full domain for prod
      def default_url_options
        {host: 'localhost:3000'}
      end

      # It is safe to assume that the rake request is legit
      def protect_against_forgery?
        false
      end
    end

    # build a simple controller to process the view
    controller = ActionController::Base.new
    controller.class_eval do
      include Rails.application.routes.url_helpers
      include ::ApplicationHelper
    end

    # build a fake request
    controller.request = ActionDispatch::TestRequest.new

    # build the rake view with the path to the app views
    view = RakeActionView.new(Rails.root.join('app', 'views'), {}, controller)

    # example assigning instance @variables to the view
    view.assign( :user => User.first )

    # Render the view to html
    html = view.render(template: 'relative/path/to/template', layout: 'layouts/example')

    # Write html to temp file and then copy to destination
    temp = Tempfile.new('example_file')
    temp.write(html)
    FileUtils.cp( temp.path, 'path/to/exmple_file' )

    # optionally set permissions on file
    File.chmod(0774, 'path/to/exmple_file')

    # close up the temp file
    temp.close
    temp.unlink
  end