How do I download files uploaded with Exfile?

juan · March 1, 2018, 10:16pm

Hi,

I am developing an application on phoenix framework v 1.3. I have managed to upload files with exfile. I still do not know how to download the files. Do any of you have a file upload and download function? It would be useful to reuse code.

Thank you !

dokuzbir · March 2, 2018, 6:15am

you can put a link in templates with file path

for example

<%= link "file", to: "/uploads/file.zip" %>

or

   conn
    |> put_resp_content_type("application/zip")
    |> put_resp_header("content-disposition", "attachment; filename=\"file.zip\"")
    |> send_resp(200, "uploads/file.zip")

juan · March 2, 2018, 1:13pm

I get the url in the template with <% = exfile_url (@conn, @ user.img)%>. How can I get the url in <% = link" file ", to:" /uploads/file.zip "%>

Thank you!

dokuzbir · March 2, 2018, 1:22pm

But if file is image you cant download directly with a link. You can manually save.
<%= link "file", to: "#{exfile_url(@conn, @user.img)}" %>

maybe you just want to show image ?
<img src="<%= exfile_url(@conn, @user.img)%>">

you should use that function

conn
    |> put_resp_content_type("application/zip")
    |> put_resp_header("content-disposition", "attachment; filename=\"file.zip\"")
    |> send_resp(200, "uploads/file.zip")

Is that a hobby project?

juan · March 2, 2018, 1:31pm

Yes, it is a project to learn. The variable is called img, but it stores images, pdf or docx, it will change the name of the variable to file.

Do I have to put in the controller something like download, to use the code that he gives me?

dokuzbir · March 2, 2018, 1:38pm

yes you should put that function in controller

juan · March 2, 2018, 1:45pm

I try with <% = link" file ", to:" # {exfile_url (@conn, @ user.img)} "%> the browser takes me to another page, but does not download.

I was reviewing the uploads directory and store the files without format, as encrypted

exfile handles the following structure

dokuzbir · March 2, 2018, 1:52pm

then first you should decrypt it . I dont know how ex_file handles that.

juan · March 2, 2018, 1:54pm

Do you have any projects that upload and download files, in which you can see the controller, router, model and templete?

dokuzbir · March 2, 2018, 2:00pm

Dont try directly hard method. First try without encrypt if it works. Try your chance with encrypt

dokuzbir · March 2, 2018, 2:20pm

Create a path in router

get "/download", DownloadController, :download

add that function in DownloadController

 def download(conn, %{"file_path" => file_path})
   conn
    |> put_resp_header("content-disposition", "attachment; filename=\"test-file.jpg\"")
    |> send_resp(200, file_path)
  end

and add a link to any page
<%= link "Download", to: download_path(@conn, :download, file_path: exfile_url(@conn, @user.img) %>

Maybe that helps you

juan · March 2, 2018, 2:34pm

It generates this error

== Compilation error in file lib/hello_web/views/user_view.ex ==
** (TokenMissingError) lib/hello_web/templates/user/show.html.eex:7: missing terminator: ) (for “(” starting at line 7)
(eex) lib/eex/compiler.ex:45: EEx.Compiler.generate_buffer/4
(phoenix) lib/phoenix/template.ex:378: Phoenix.Template.compile/2
(phoenix) lib/phoenix/template.ex:186: anonymous fn/3 in Phoenix.Template.“MACRO-before_compile”/2
(elixir) lib/enum.ex:1899: Enum.“-reduce/3-lists^foldl/2-0-”/3
(phoenix) expanding macro: Phoenix.Template.before_compile/1
lib/hello_web/views/user_view.ex:1: HelloWeb.UserView (module)
(elixir) lib/kernel/parallel_compiler.ex:198: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6

dokuzbir · March 2, 2018, 2:38pm

try this
<%= link “Download”, to: download_path(@conn, :download, file_path: exfile_url(@conn, @user.img)) %>

juan · March 2, 2018, 2:40pm

It generates this new error

== Compilation error in file lib/hello_web/views/user_view.ex ==
** (SyntaxError) lib/hello_web/templates/user/show.html.eex:7: unexpected token: ““” (column 7, codepoint U+201C)
(eex) lib/eex/compiler.ex:45: EEx.Compiler.generate_buffer/4
(phoenix) lib/phoenix/template.ex:378: Phoenix.Template.compile/2
(phoenix) lib/phoenix/template.ex:186: anonymous fn/3 in Phoenix.Template.“MACRO-before_compile”/2
(elixir) lib/enum.ex:1899: Enum.“-reduce/3-lists^foldl/2-0-”/3
(phoenix) expanding macro: Phoenix.Template.before_compile/1
lib/hello_web/views/user_view.ex:1: HelloWeb.UserView (module)
(elixir) lib/kernel/parallel_compiler.ex:198: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6

dokuzbir · March 2, 2018, 2:44pm

Delete link and add only that. what is output?
<%= exfile_url(@conn, @user.img) %>

juan · March 2, 2018, 2:47pm

In this way it works, generates in text

http://localhost:4000/attachments/e_z2UosxXgZJdM7LKuO2g7A8qlphArEtOCxtxvZFRyw=/cache/c2b2f68c353594f75da61daddc61d4bb201e24eeb742564a3eed3ab9a3c7/file

dokuzbir · March 2, 2018, 2:51pm

use that
<%= link “Download”, to: download_path(@conn, :download, file_path: exfile_path(@conn, @user.img)) %>

juan · March 2, 2018, 2:55pm

It produced error. Then try with <% = link Download, to: download_path (@conn,: download, file_path: exfile_path (@conn, @ user.img))%> and generate this error > == Compilation error in file lib/hello_web/views/user_view.ex ==

** (CompileError) lib/hello_web/templates/user/show.html.eex:7: undefined function download_path/3
(stdlib) lists.erl:1338: :lists.foreach/2
(stdlib) erl_eval.erl:670: :erl_eval.do_apply/6
(elixir) lib/kernel/parallel_compiler.ex:198: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6

dokuzbir · March 2, 2018, 2:57pm

you should create new DownloadController. and add that function to inside controller

def download(conn, %{"file_path" => file_path})
   conn
    |> put_resp_header("content-disposition", "attachment; filename=\"test-file.jpg\"")
    |> send_resp(200, file_path)
  end

juan · March 2, 2018, 3:01pm

Compile! but it generates this error already with the server running

[error] #PID<0.484.0> running HelloWeb.Endpoint terminated
Server: 191.232.179.128:4000 (http)
Request: GET /users/3
** (exit) an exception was raised:
    ** (FunctionClauseError) no function clause matching in Exfile.Phoenix.Helpers.exfile_path/2
        (exfile) lib/exfile/phoenix/helpers.ex:42: Exfile.Phoenix.Helpers.exfile_path(%Plug.Conn{adapter: {Plug.Adapters.Cowboy.Conn, :...}, assigns: %{layout: {HelloWeb.LayoutView, "app.html"}, user: %Hello.Accounts.User{__meta__: #Ecto.Schema.Metadata<:loaded, "users">, id: 3, img: %Exfile.File{backend: %Exfile.Backend{backend_mod: Exfile.Backend.FileSystem, backend_name: "cache", directory: "/home/codes/hello/tmp/cache", hasher: Exfile.Hasher.Random, max_size: -1, meta: %{ttl: :infinity}, postprocessors: [], preprocessors: []}, backend_meta: %{absolute_path: "/home/codes/hello/tmp/cache/c2b2f68c353594f75da61daddc61d4bb201e24eeb742564a3eed3ab9a3c7"}, id: "c2b2f68c353594f75da61daddc61d4bb201e24eeb742564a3eed3ab9a3c7", meta: %{}}, inserted_at: ~N[2018-03-01 14:40:17.696010], name: "a", updated_at: ~N[2018-03-02 13:35:16.654989], username: "a"}}, before_send: [#Function<0.59940076/1 in Plug.CSRFProtection.call/2>, #Function<4.112730735/1 in Phoenix.Controller.fetch_flash/2>, #Function<0.45862765/1 in Plug.Session.before_send/2>, #Function<1.130626273/1 in Plug.Logger.call/2>, #Function<0.832222/1 in Phoenix.LiveReloader.before_send_inject_reloader/2>], body_params: %{}, cookies: %{"_hello_key" => "SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYY2theDZvc2M3ZlRlZ1N1R0dQeis2Zz09._SB3jsjQpfSmmi8i4tDTGSBs9MpiwuGdwO0WjzM6FT8"}, halted: false, host: "191.232.179.128", method: "GET", owner: #PID<0.484.0>, params: %{"id" => "3"}, path_info: ["users", "3"], path_params: %{"id" => "3"}, peer: {{181, 50, 101, 215}, 52604}, port: 4000, private: %{HelloWeb.Router => {[], %{Exfile.Router => ["attachments"]}}, :phoenix_action => :show, :phoenix_controller => HelloWeb.UserController, :phoenix_endpoint => HelloWeb.Endpoint, :phoenix_flash => %{}, :phoenix_format => "html", :phoenix_layout => {HelloWeb.LayoutView, :app}, :phoenix_pipelines => [:browser], :phoenix_router => HelloWeb.Router, :phoenix_template => "show.html", :phoenix_view => HelloWeb.UserView, :plug_session => %{"_csrf_token" => "ckax6osc7fTegSuGGPz+6g=="}, :plug_session_fetch => :done}, query_params: %{}, query_string: "", remote_ip: {181, 50, 101, 215}, req_cookies: %{"_hello_key" => "SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYY2theDZvc2M3ZlRlZ1N1R0dQeis2Zz09._SB3jsjQpfSmmi8i4tDTGSBs9MpiwuGdwO0WjzM6FT8"}, req_headers: [{"host", "191.232.179.128:4000"}, {"connection", "keep-alive"}, {"cache-control", "max-age=0"}, {"upgrade-insecure-requests", "1"}, {"user-agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36"}, {"accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8"}, {"accept-encoding", "gzip, deflate"}, {"accept-language", "es-ES,es;q=0.9,es-MX;q=0.8,en;q=0.7"}, {"cookie", "_hello_key=SFMyNTY.g3QAAAABbQAAAAtfY3NyZl90b2tlbm0AAAAYY2theDZvc2M3ZlRlZ1N1R0dQeis2Zz09._SB3jsjQpfSmmi8i4tDTGSBs9MpiwuGdwO0WjzM6FT8"}], request_path: "/users/3", resp_body: nil, resp_cookies: %{}, resp_headers: [{"cache-control", "max-age=0, private, must-revalidate"}, {"x-request-id", "9ahv5gavppl2dr2u8img475bjm8pmv28"}, {"x-frame-options", "SAMEORIGIN"}, {"x-xss-protection", "1; mode=block"}, {"x-content-type-options", "nosniff"}], scheme: :http, script_name: [], secret_key_base: "EtRm+bNvFVjfnA1qXbVp+CMaa0fomTvW3QNElmbVNKGTH7yNrlfhQFjBQLgE1ynr", state: :unset, status: nil}, %Exfile.File{backend: %Exfile.Backend{backend_mod: Exfile.Backend.FileSystem, backend_name: "cache", directory: "/home/codes/hello/tmp/cache", hasher: Exfile.Hasher.Random, max_size: -1, meta: %{ttl: :infinity}, postprocessors: [], preprocessors: []}, backend_meta: %{absolute_path: "/home/codes/hello/tmp/cache/c2b2f68c353594f75da61daddc61d4bb201e24eeb742564a3eed3ab9a3c7"}, id: "c2b2f68c353594f75da61daddc61d4bb201e24eeb742564a3eed3ab9a3c7", meta: %{}})
        (hello) lib/hello_web/templates/user/show.html.eex:7: HelloWeb.UserView."show.html"/1
        (hello) lib/hello_web/templates/layout/app.html.eex:29: HelloWeb.LayoutView."app.html"/1
        (phoenix) lib/phoenix/view.ex:332: Phoenix.View.render_to_iodata/3
        (phoenix) lib/phoenix/controller.ex:740: Phoenix.Controller.do_render/4
        (hello) lib/hello_web/controllers/user_controller.ex:1: HelloWeb.UserController.action/2
        (hello) lib/hello_web/controllers/user_controller.ex:1: HelloWeb.UserController.phoenix_controller_pipeline/2
        (hello) lib/hello_web/endpoint.ex:1: HelloWeb.Endpoint.instrument/4
        (phoenix) lib/phoenix/router.ex:278: Phoenix.Router.__call__/1
        (hello) lib/hello_web/endpoint.ex:1: HelloWeb.Endpoint.plug_builder_call/2
        (hello) lib/plug/debugger.ex:99: HelloWeb.Endpoint."call (overridable 3)"/2
        (hello) lib/hello_web/endpoint.ex:1: HelloWeb.Endpoint.call/2
        (plug) lib/plug/adapters/cowboy/handler.ex:15: Plug.Adapters.Cowboy.Handler.upgrade/4
        (cowboy) /home/codes/hello/deps/cowboy/src/cowboy_protocol.erl:442: :cowboy_protocol.execute/4