postprocess/finalize hook, custom error pages

9 months ago · ff36326ec8
2 changed files with 124 additions and 38 deletions
--- a/hyde.rb
+++ b/hyde.rb
@ -1,13 +1,53 @@
 require 'mime-types'
 require 'webrick'
 require 'uri'
+require 'pp'

 module Hyde
  # Branding and version
  VERSION = "0.5 (alpha)"
  attr_reader :VERSION
-  VLINE = "<ADDRESS>\n      Hyde/#{Hyde::VERSION} on WEBrick/#{WEBrick::VERSION} (Ruby/#{RUBY_VERSION}/#{RUBY_RELEASE_DATE})\n    </ADDRESS>"
+  VLINE = "Hyde/#{Hyde::VERSION} on WEBrick/#{WEBrick::VERSION} (Ruby/#{RUBY_VERSION}/#{RUBY_RELEASE_DATE})\n"
  attr_reader :VLINE
+
+  def error_template(errortext,backtrace)
+    <<HTMLEOF
+<!DOCTYPE HTML>
+<html>
+    <head>
+        <title>#{WEBrick::HTMLUtils.escape(errortext)}</title>
+        <style> .header {background-color: #CC7878; padding: 0.5rem; border-bottom-width: 0.2rem; border-bottom-style: solid; border-bottom-color: #202222; overflow: auto;} .title { font-weight: bolder; font-size: 36px; margin: 0 0; text-shadow: 1px 1px 1px #202222, 2px 2px 2px #404444; float: left } body { margin: 0;
+} .text { font-size 1rem; } .small { color: #7D7D7D; font-size: 12px;} .code { font-family: monospace; font-size: 0.7rem; } </style>
+    </head>
+    <body>
+        <div class="header">
+            <p class="title">HYDE</p>
+            <p style="float: right"><a href="https://adastra7.net/git/yessiest/hyde">Source code</a></p>
+        </div>
+        <div style="padding: 0.5rem">
+            <p class="text">#{WEBrick::HTMLUtils.escape(errortext)}</p>
+            <pre><code class="text code">
+#{WEBrick::HTMLUtils.escape(backtrace) or "\n\n\n"}
+            </code></pre>
+            <hr/>
+            <p class="small">#{WEBrick::HTMLUtils.escape(VLINE)}</p>
+        </div>
+    </body>
+</html>
+HTMLEOF
+  end
+  module_function :error_template
+
+  WEBrick::HTTPResponse.class_exec do
+    attr_accessor :recent_backtrace
+    public
+    def set_backtrace(backtrace)
+      @recent_backtrace = backtrace
+    end
+    def create_error_page
+      @body = Hyde.error_template(@reason_phrase,@recent_backtrace)
+    end
+  end
  
  class Server < WEBrick::HTTPServer
    def initialize(config={},&setup)
@ -15,32 +55,29 @@ module Hyde
      @hyde_pathspec = Hyde::Pathspec.new "/", &setup
      self.mount_proc '/' do |req,res|
        context = Hyde::Context.new(req.path, req, res)
-        while context and (not context.exit_loop) do
-          context.exit_loop = true
-          context = catch :controlled_exit do 
-            @hyde_pathspec._match(context)
-            context
+        begin
+          while context and (not context.exit_loop) do
+            context.exit_loop = true
+            context = catch :controlled_exit do 
+              @hyde_pathspec._match(context)
+              context
+            end
+            while postprocessor = context.queue_postprocess.shift do
+              postprocessor.call(context)
+            end
+          end
+          while finalizer = context.queue_finalize.shift do
+            finalizer.call(context)
          end
+        rescue Exception => e
+          puts e.message
+          puts e.backtrace
+          res.set_backtrace "#{e.message} (#{e.class})\n#{e.backtrace.join "\n"}"
+          res.status = 500
        end
      end
    end
  end
-
-  module ErrorPages
-    # 404 text
-    def error404(request, filepath)
-      request.response.status = 404
-      if request.handles.include? 404
-        request.response.body = request.handles[404].call(
-          filepath
-        ) 
-      else
-        request.response.body = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0//EN\">\n<HTML>\n  <HEAD><TITLE>File not found</TITLE></HEAD>\n  <BODY>\n    <H1>File not found</H1>\n    #{filepath}\n    <HR>\n    #{Hyde::VLINE}\n  </BODY>\n</HTML>"      
-      end
-      request.response["Content-Type"] = 'text/html'
-    end
-    module_function :error404
-  end
  
  # Interchangeable glob/regex/string pattern matching
  module PatternMatching
@ -110,6 +147,19 @@ module Hyde
      new_context.exit_loop = false
      throw :controlled_exit, new_context
    end
+    def die(code, message=nil, backtrace="")
+      @current_context.response.status = code
+      @current_context.response.set_backtrace(backtrace)
+      if not message then
+        message = WEBrick::HTTPStatus::StatusMessage[code]
+      end
+      if @current_context.codehandlers[code] then
+        @current_context.codehandlers[code].call(@current_context, message, backtrace)
+      else
+        @current_context.response.body = Hyde.error_template(message, backtrace)
+      end
+      throw :controlled_exit, @current_context
+    end
  end

  # Request wrapper class
@ -119,24 +169,42 @@ module Hyde
      @filepath = ""
      @request = request
      @response = response
-      @handles = {}
      @indexlist = []
      @vars = {}
+      @codehandlers = {}
+      @queue_postprocess = []
+      @queue_finalize = []
      @exit_loop = false
    end
    def self.rewrite(pctx,newpath)
-      newctx = self.new(newpath,pctx.request,pctx.response)
+      newctx = Context.new(newpath,pctx.request,pctx.response)
      newctx.vars = pctx.vars
+      newctx.queue_finalize = pctx.queue_finalize.clone
+      newctx.queue_postprocess = pctx.queue_postprocess.clone
      return newctx
    end
+    def enqueue_finalizer(dup: false, &block)
+      if block_given? then
+        if dup or not @queue_finalize.include? block then 
+          @queue_finalize.append(block)
+        end
+      end
+    end
+    def enqueue_postprocessor(&block)
+      if block_given? then
+        @queue_postprocess.append(block)
+      end
+    end
    attr_reader :request
    attr_reader :response
-    attr_accessor :filepath
+    attr_accessor :queue_finalize
+    attr_accessor :queue_postprocess
    attr_accessor :path
-    attr_accessor :handles
    attr_accessor :indexlist
+    attr_accessor :filepath
    attr_accessor :exit_loop
    attr_accessor :vars
+    attr_accessor :codehandlers
  end

  # Context object with safe path encapsulation
@ -146,15 +214,18 @@ module Hyde
      @filepath = request.filepath
      @request = request.request
      @response = request.response
-      @handles = request.handles
      @indexlist = request.indexlist
      @exit_loop = request.exit_loop
      @vars = request.vars
+      @codehandlers = request.codehandlers
+      @queue_postprocess = request.queue_postprocess
+      @queue_finalize = request.queue_finalize
    end
    undef :path=
    undef :filepath=
-    undef :handles=
    undef :indexlist=
+    undef :queue_postprocess=
+    undef :queue_finalize=
  end

  # Handler classes
@ -185,6 +256,7 @@ module Hyde
    def _match(request)
      return super if @block
      if _match? request.path, request then
+        @current_context = request 
        match_path = _normalize_input(request.path).match(@path)[0]
        filepath = request.filepath+match_path
        begin
@ -194,7 +266,7 @@ module Hyde
          request.response.body = data
          request.response["Content-Type"] = mimetype
        rescue Errno::ENOENT
-          Hyde::ErrorPages::error404 request, request.request.path
+          die(404) 
        end
      end
    end
@ -282,10 +354,10 @@ module Hyde
  class Pathspec
    include Hyde::PatternMatching
    include Hyde::Handlers
+    include Hyde::PublicContextControlMethods
    def initialize (path, root_path: nil, safe_regexp: true, &block)
      _prep_path path, safe_regexp: safe_regexp
      @chain = []
-      @handles = {}
      @root_override = root_path
      @remap = false
      self.instance_exec &block
@ -308,15 +380,23 @@ module Hyde
    end
    def index(list)
      @indexlist = list if list.kind_of? Array
-    end
-    def handle(code, &block)
-      @handles[code] = block
+      @indexlist = [list] if list.kind_of? String
    end
    def preprocess(&block)
      @preprocessor = block
    end
-    def _match(request) 
+    def postprocess(&block)
+      @postprocessor = block 
+    end
+    def finalize(dup: false, &block)
+      @finalizer = block
+      @finalizer_dup = dup
+    end
+    def _match(request)
+      @current_context = request
      self.instance_exec request, &@preprocessor if @preprocessor
+      request.enqueue_postprocessor &@postprocessor if @preprocessor
+      request.enqueue_finalizer dup: @finalizer_dup, &@finalizer if @finalizer
      if _match? request.path, request then
        match_path = _normalize_input(request.path).match(@path)
        next_path = match_path[0]
@ -329,8 +409,7 @@ module Hyde
        else
          request.filepath = request.filepath+next_path+"/"
        end
-        # parameter overrides overlaying
-        @handles.each_pair { |k,v| request.handles[k] = v }
+        # redefine indexing parameters if they are defined for a pathspec 
        request.indexlist = @indexlist if @indexlist
        # do directory indexing
        if cut_path.match /^\/?$/ then
@ -346,10 +425,11 @@ module Hyde
        next_pathspec = @chain.find { |x| x._match? cut_path, request }
        next_pathspec._match request if next_pathspec
        unless next_pathspec then
-          # throw 404 if nowhere to go
-          Hyde::ErrorPages::error404 request, request.request.path
+          # die and throw up if nowhere to go
+          die(404)
        end
      end
+      @current_context = nil
    end
  end
 end
--- a/test_combined.rb
+++ b/test_combined.rb
@ -8,6 +8,12 @@ server = Hyde::Server.new Port: 8000 do
    preprocess do |ctx|
      puts "#{ctx} entered fully virtual directory!"
    end
+    postprocess do |ctx|
+      puts "#{ctx} reached endpoint!"
+    end
+    finalize do |ctx|
+      puts "#{ctx} finished processing!"
+    end
    get "portal" do |ctx|
      ctx.vars[:ass] = true
      rewrite "/about/hyde"