Decouple from HTTP::Server::Context (#49)

* Decouple exception page from `HTTP::Server::Context`

* Give defaults to collection properties
Add test case

README.md

@@ -47,7 +47,7 @@ class MyErrorHandler
       raise SomeError.new("Something went wrong")
     rescue e
       context.response.status_code = 500
-      context.response.print MyApp::ExceptionPage.for_runtime_exception(context, e).to_s
+      context.response.print MyApp::ExceptionPage.new context, e
     end
   end
 ```

spec/exception_page_spec.cr

@@ -16,6 +16,10 @@ describe ExceptionPage do
     flow.view_error_page
     flow.should_have_additional_message_lines
   end
+
+  it "allows instantiating one manually" do
+    MyApp::ExceptionPage.new Exception.new("Oh noes"), "SEARCH", "/users", :im_a_teapot
+  end
 end
 
 class ErrorDebuggingFlow < LuckyFlow

spec/support/test_handler.cr

@@ -10,14 +10,14 @@ class TestHandler
         raise CustomException.new("Something went very wrong\nBut wait, there's more!")
       rescue e : CustomException
         context.response.content_type = "text/html"
-        context.response.print MyApp::ExceptionPage.for_runtime_exception(context, e)
+        context.response.print MyApp::ExceptionPage.new context, e
       end
     else
       begin
         raise CustomException.new("Something went very wrong")
       rescue e : CustomException
         context.response.content_type = "text/html"
-        context.response.print MyApp::ExceptionPage.for_runtime_exception(context, e)
+        context.response.print MyApp::ExceptionPage.new context, e
       end
     end
   end

src/exception_page.cr

@@ -26,26 +26,57 @@ abstract class ExceptionPage
         "all"
       end
     end
-
-    def host_from_context(context)
-      if host = context.request.headers["Host"]?
-        host = "http://#{host}"
-      end
-      host
-    end
   end
 
   include Helpers
 
-  @params : Hash(String, String)
-  @headers : Hash(String, Array(String))
-  @session : Hash(String, HTTP::Cookie)
+  def self.new(context : HTTP::Server::Context, exception : Exception)
+    new(
+      exception,
+      context.request.method,
+      context.request.path,
+      context.response.status,
+      nil,
+      context.request.query_params,
+      context.response.headers,
+      context.response.cookies,
+      exception.message,
+    )
+  end
+
   @method : String
   @path : String
+  @status : HTTP::Status
+  @title : String
+  @params : URI::Params
+  @headers : HTTP::Headers
+  @cookies : HTTP::Cookies?
   @message : String
-  @query : String
+  @url : String
   @frames : Array(Backtracer::Backtrace::Frame)
-  @title : String
+
+  def initialize(
+    exception : Exception,
+    @method : String,
+    @path : String,
+    @status : HTTP::Status,
+    title : String? = nil,
+    @params : URI::Params = URI::Params.new,
+    @headers : HTTP::Headers = HTTP::Headers.new,
+    @cookies : HTTP::Cookies = HTTP::Cookies.new,
+    message : String? = nil,
+    url : String? = nil
+  )
+    @title = title || "An Error Occurred: #{@status.description}"
+    @message = message || "Something went wrong"
+    @url = url || "#{@headers["host"]?}#{@path}"
+
+    @frames = if exception.backtrace?
+                Backtracer.parse(exception.backtrace, configuration: backtracer).frames
+              else
+                [] of Backtracer::Backtrace::Frame
+              end
+  end
 
   abstract def styles : Styles
 
@@ -68,32 +99,6 @@ abstract class ExceptionPage
   def backtracer : Backtracer::Configuration?
   end
 
-  # :nodoc:
-  def initialize(context : HTTP::Server::Context, @message, @title, @frames)
-    @params = context.request.query_params.to_h
-    @headers = context.response.headers.to_h
-    @method = context.request.method
-    @path = context.request.path
-    @url = "#{host_from_context(context)}#{context.request.path}"
-    @query = context.request.query_params.to_s
-    @session = context.response.cookies.to_h
-  end
-
-  def initialize(context : HTTP::Server::Context, ex : Exception)
-    title = "Error #{context.response.status_code}"
-    frames =
-      if ex.backtrace?
-        Backtracer.parse(ex.backtrace, configuration: backtracer).frames
-      else
-        [] of Backtracer::Backtrace::Frame
-      end
-    initialize(context, ex.message.to_s, title: title, frames: frames)
-  end
-
-  def self.for_runtime_exception(context : HTTP::Server::Context, ex : Exception)
-    new(context, ex)
-  end
-
   ECR.def_to_s "#{__DIR__}/exception_page/exception_page.ecr"
 end
 

src/exception_page/exception_page.ecr

@@ -813,7 +813,7 @@
 
             <dl>
                 <dt>Query string:</dt>
-                <dd class="code-quote"><%= HTML.escape(@query) %></dd>
+                <dd class="code-quote"><%= HTML.escape(@params.to_s) %></dd>
             </dl>
         </details>
 
@@ -827,13 +827,13 @@
             <% end %>
         </details>
 
-        <% if (session = @session) && !session.empty? %>
+        <% if (cookies = @cookies) && !cookies.empty? %>
         <details class="conn-details">
             <summary>Session</summary>
-            <% session.each do |key, value| %>
+            <% cookies.each do |cookie| %>
             <dl>
-                <dt><%= HTML.escape(key) %></dt>
-                <dd><pre><%= HTML.escape(value.inspect) %></pre></dd>
+                <dt><%= HTML.escape(cookie.name) %></dt>
+                <dd><pre><%= HTML.escape(cookie.value.inspect) %></pre></dd>
             </dl>
             <% end %>
         </details>