fix warnings; do not save config.command_prefix in agent

lib/pdf_generator.ex

@@ -69,7 +69,6 @@ defmodule PdfGenerator do
           PdfGenerator.PathAgent, [[
             wkhtml_path:    Application.get_env(:pdf_generator, :wkhtml_path),
             pdftk_path:     Application.get_env(:pdf_generator, :pdftk_path),
-            command_prefix: Application.get_env(:pdf_generator, :command_prefix),
           ]]
         )
       ]
@@ -122,7 +121,7 @@ defmodule PdfGenerator do
 
     executable     = wkhtml_path
     arguments      = List.flatten( [ shell_params, html_file, pdf_file ] )
-    command_prefix = Keyword.get( options, :command_prefix ) || PdfGenerator.PathAgent.get |> Map.get( :command_prefix )
+    command_prefix = Keyword.get( options, :command_prefix ) || Application.get_env( :pdf_generator, :command_prefix )
 
     # allow for xvfb-run wkhtmltopdf arg1 arg2
     # or sudo wkhtmltopdf ...
@@ -157,8 +156,17 @@ defmodule PdfGenerator do
   def encrypt_pdf( pdf_input_path, user_pw, owner_pw ) do
     pdftk_path = PdfGenerator.PathAgent.get.pdftk_path
 
-    if owner_pw == nil, do: owner_pw = Misc.Random.string(16)
-    if user_pw  == nil, do: user_pw  = Misc.Random.string(16)
+    owner_pw =
+      case owner_pw do
+        nil -> Misc.Random.string(16)
+        _   -> owner_pw
+      end
+
+    user_pw =
+      case user_pw do
+        nil -> Misc.Random.string(16)
+        _   -> user_pw
+      end
 
     pdf_output_file  = Path.join System.tmp_dir, Misc.Random.string <> ".pdf"
 

lib/pdf_generator_path_agent.ex

@@ -3,27 +3,25 @@ defmodule PdfGenerator.PathAgent do
   defstruct wkhtml_path: nil, pdftk_path: nil
 
   @moduledoc """
-  Will check system requirements on startup and keep 
+  Will check system requirements on startup and keep
   a path map as state in an Agent process.
   """
-  
+
   @name __MODULE__
 
   def start_link( path_options ) do
     Agent.start_link( __MODULE__, :init_opts, [ path_options ], name: @name  )
   end
 
   def init_opts( paths_from_options ) do
-
     # options override system default paths
-    options = 
+    options =
       [
         wkhtml_path:    System.find_executable( "wkhtmltopdf" ),
-        pdftk_path:     System.find_executable( "pdftk" ),
-        # command_prefix: System.find_executable( "xvfb-run" )
-      ] 
+        pdftk_path:     System.find_executable( "pdftk" )
+      ]
       ++ paths_from_options
-      |> Enum.filter( fn { _, v } -> v != nil end ) 
+      |> Enum.filter( fn { _, v } -> v != nil end )
 
     # at least, wkhtmltopdf executable sould be there
     if Keyword.fetch!( options, :wkhtml_path ) == nil do
@@ -44,5 +42,5 @@ defmodule PdfGenerator.PathAgent do
   def get do
     Agent.get( @name, fn( data ) -> data end )
   end
-  
+
 end

test/pdf_generator_test.exs

@@ -15,13 +15,13 @@ defmodule PdfGeneratorTest do
     file_info = File.stat! temp_filename
     assert file_info.size > 0
     pdf = File.read! temp_filename
-    
+
     # PDF header should be present
     assert String.slice( pdf, 0, 6) == "%PDF-1"
   end
 
   test "command prefix with noop env" do
-    {:ok, temp_filename } = PdfGenerator.generate @html, [ command_prefix: "env" ]
+    {:ok, _temp_filename } = PdfGenerator.generate @html, [ command_prefix: "env" ]
   end
 
 end