Ruby-on-rails Rails 3：如何在控制器中获取图像路径？
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Rails 3: How to get image path in Controller?
提问by Misha Moroshko
To get the image path in Controller I use the following method:
要在控制器中获取图像路径，我使用以下方法：
class AssetsController < ApplicationController
def download(image_file_name)
path = Rails.root.join("public", "images", image_file_name).to_s
send_file(path, ...)
end
end
Is there a better method to find the path ?
有没有更好的方法来找到路径？
回答by deefour
ActionController::Base.helpers.asset_path('missing_file.jpg')
回答by Matt Huggins
Not sure if this was added as early as Rails 3, but is definitely working in Rails 3.1. You can now access the view_contextfrom your controller, which allows you to call methods that are normally accessible to your views:
不确定这是否早在 Rails 3 中添加，但肯定在 Rails 3.1 中工作。您现在可以view_context从控制器访问，这允许您调用通常可以访问您的视图的方法：
class AssetsController < ApplicationController
def download(image_file_name)
path = view_context.image_path(image_file_name)
# ... use path here ...
end
end
Note that this will give you the publicly accessible path (e.g.: "/assets/foobar.gif"), not the local filesystem path.
请注意，这将为您提供可公开访问的路径（例如：“/assets/foobar.gif”），而不是本地文件系统路径。
回答by Ricardo Rivas
view_context.image_path('noimage.jpg')
view_context.image_path('noimage.jpg')
回答by ilgam
Asset url:
资产网址：
ActionController::Base.helpers.asset_path(my_path)
Image url:
图片网址：
ActionController::Base.helpers.image_path(my_path)
回答by Devin
view_contextworks for me in Rails 4.2 and Rails 5.
view_context在 Rails 4.2 和 Rails 5 中对我有用。
Find some codes in Rails repo explains view_context:
在 Rails repo 中找到一些代码解释view_context：
# definition
module ActionView
# ...
module Rendering
# ...
def view_context
view_context_class.new(view_renderer, view_assigns, self)
end
end
end
# called in controller module
module ActionController
# ...
module Helpers
# Provides a proxy to access helper methods from outside the view.
def helpers
@_helper_proxy ||= view_context
end
end
end
回答by Marius Butuc
You might want to check out image_path(image.png)for your scenario.
您可能想要查看image_path(image.png)您的场景。
Here are the examples from the docs:
以下是文档中的示例：
image_path("edit") # => "/images/edit"
image_path("edit.png") # => "/images/edit.png"
image_path("icons/edit.png") # => "/images/icons/edit.png"
image_path("/icons/edit.png") # => "/icons/edit.png"
image_path("http://www.example.com/img/edit.png") # => "http://www.example.com/img/edit.png"
