Class: Rack::ShowExceptions
- Inherits:
-
Object
- Object
- Rack::ShowExceptions
- Defined in:
- lib/rack/show_exceptions.rb
Overview
Rack::ShowExceptions catches all exceptions raised from the app it wraps. It shows a useful backtrace with the sourcefile and clickable context, the whole Rack environment and the request data.
Be careful when you use this on public-facing sites as it could reveal information helpful to attackers.
Defined Under Namespace
Classes: Frame
Constant Summary collapse
- CONTEXT =
7
- TEMPLATE =
adapted from Django <www.djangoproject.com> Copyright © Django Software Foundation and individual contributors. Used under the modified BSD license: www.xfree86.org/3.3.6/COPYRIGHT2.html#5
ERB.new(<<-'HTML'.gsub(/^ /, '')) <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html lang="en"> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8" /> <meta name="robots" content="NONE,NOARCHIVE" /> <title><%=h exception.class %> at <%=h path %></title> <style type="text/css"> html * { padding:0; margin:0; } body * { padding:10px 20px; } body * * { padding:0; } body { font:small sans-serif; } body>div { border-bottom:1px solid #ddd; } h1 { font-weight:normal; } h2 { margin-bottom:.8em; } h2 span { font-size:80%; color:#666; font-weight:normal; } h3 { margin:1em 0 .5em 0; } h4 { margin:0 0 .5em 0; font-weight: normal; } table { border:1px solid #ccc; border-collapse: collapse; background:white; } tbody td, tbody th { vertical-align:top; padding:2px 3px; } thead th { padding:1px 6px 1px 3px; background:#fefefe; text-align:left; font-weight:normal; font-size:11px; border:1px solid #ddd; } tbody th { text-align:right; color:#666; padding-right:.5em; } table.vars { margin:5px 0 2px 40px; } table.vars td, table.req td { font-family:monospace; } table td.code { width:100%;} table td.code div { overflow:hidden; } table.source th { color:#666; } table.source td { font-family:monospace; white-space:pre; border-bottom:1px solid #eee; } ul.traceback { list-style-type:none; } ul.traceback li.frame { margin-bottom:1em; } div.context { margin: 10px 0; } div.context ol { padding-left:30px; margin:0 10px; list-style-position: inside; } div.context ol li { font-family:monospace; white-space:pre; color:#666; cursor:pointer; } div.context ol.context-line li { color:black; background-color:#ccc; } div.context ol.context-line li span { float: right; } div.commands { margin-left: 40px; } div.commands a { color:black; text-decoration:none; } #summary { background: #ffc; } #summary h2 { font-family: monospace; font-weight: normal; color: #666; white-space: pre-wrap; } #summary ul#quicklinks { list-style-type: none; margin-bottom: 2em; } #summary ul#quicklinks li { float: left; padding: 0 1em; } #summary ul#quicklinks>li+li { border-left: 1px #666 solid; } #explanation { background:#eee; } #template, #template-not-exist { background:#f6f6f6; } #template-not-exist ul { margin: 0 0 0 20px; } #traceback { background:#eee; } #requestinfo { background:#f6f6f6; padding-left:120px; } #summary table { border:none; background:transparent; } #requestinfo h2, #requestinfo h3 { position:relative; margin-left:-100px; } #requestinfo h3 { margin-bottom:-1em; } .error { background: #ffc; } .specific { color:#cc3300; font-weight:bold; } </style> <script type="text/javascript"> //<!-- function getElementsByClassName(oElm, strTagName, strClassName){ // Written by Jonathan Snook, http://www.snook.ca/jon; // Add-ons by Robert Nyman, http://www.robertnyman.com var arrElements = (strTagName == "*" && document.all)? document.all : oElm.getElementsByTagName(strTagName); var arrReturnElements = new Array(); strClassName = strClassName.replace(/\-/g, "\\-"); var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$$)"); var oElement; for(var i=0; i<arrElements.length; i++){ oElement = arrElements[i]; if(oRegExp.test(oElement.className)){ arrReturnElements.push(oElement); } } return (arrReturnElements) } function hideAll(elems) { for (var e = 0; e < elems.length; e++) { elems[e].style.display = 'none'; } } window.onload = function() { hideAll(getElementsByClassName(document, 'table', 'vars')); hideAll(getElementsByClassName(document, 'ol', 'pre-context')); hideAll(getElementsByClassName(document, 'ol', 'post-context')); } function toggle() { for (var i = 0; i < arguments.length; i++) { var e = document.getElementById(arguments[i]); if (e) { e.style.display = e.style.display == 'none' ? 'block' : 'none'; } } return false; } function varToggle(link, id) { toggle('v' + id); var s = link.getElementsByTagName('span')[0]; var uarr = String.fromCharCode(0x25b6); var darr = String.fromCharCode(0x25bc); s.innerHTML = s.innerHTML == uarr ? darr : uarr; return false; } //--> </script> </head> <body> <div id="summary"> <h1><%=h exception.class %> at <%=h path %></h1> <% if exception.respond_to?(:detailed_message) %> <h2><%=h exception.detailed_message(highlight: false) %></h2> <% else %> <h2><%=h exception.message %></h2> <% end %> <table><tr> <th>Ruby</th> <td> <% if first = frames.first %> <code><%=h first.filename %></code>: in <code><%=h first.function %></code>, line <%=h frames.first.lineno %> <% else %> unknown location <% end %> </td> </tr><tr> <th>Web</th> <td><code><%=h req.request_method %> <%=h(req.host + path)%></code></td> </tr></table> <h3>Jump to:</h3> <ul id="quicklinks"> <li><a href="#get-info">GET</a></li> <li><a href="#post-info">POST</a></li> <li><a href="#cookie-info">Cookies</a></li> <li><a href="#env-info">ENV</a></li> </ul> </div> <div id="traceback"> <h2>Traceback <span>(innermost first)</span></h2> <ul class="traceback"> <% frames.each { |frame| %> <li class="frame"> <code><%=h frame.filename %></code>: in <code><%=h frame.function %></code> <% if frame.context_line %> <div class="context" id="c<%=h frame.object_id %>"> <% if frame.pre_context %> <ol start="<%=h frame.pre_context_lineno+1 %>" class="pre-context" id="pre<%=h frame.object_id %>"> <% frame.pre_context.each { |line| %> <li onclick="toggle('pre<%=h frame.object_id %>', 'post<%=h frame.object_id %>')"><%=h line %></li> <% } %> </ol> <% end %> <ol start="<%=h frame.lineno %>" class="context-line"> <li onclick="toggle('pre<%=h frame.object_id %>', 'post<%=h frame.object_id %>')"><%=h frame.context_line %><span>...</span></li></ol> <% if frame.post_context %> <ol start='<%=h frame.lineno+1 %>' class="post-context" id="post<%=h frame.object_id %>"> <% frame.post_context.each { |line| %> <li onclick="toggle('pre<%=h frame.object_id %>', 'post<%=h frame.object_id %>')"><%=h line %></li> <% } %> </ol> <% end %> </div> <% end %> </li> <% } %> </ul> </div> <div id="requestinfo"> <h2>Request information</h2> <h3 id="get-info">GET</h3> <% if req.GET and not req.GET.empty? %> <table class="req"> <thead> <tr> <th>Variable</th> <th>Value</th> </tr> </thead> <tbody> <% req.GET.sort_by { |k, v| k.to_s }.each { |key, val| %> <tr> <td><%=h key %></td> <td class="code"><div><%=h val.inspect %></div></td> </tr> <% } %> </tbody> </table> <% else %> <p>No GET data.</p> <% end %> <h3 id="post-info">POST</h3> <% if ((req.POST and not req.POST.empty?) rescue (no_post_data = "Invalid POST data"; nil)) %> <table class="req"> <thead> <tr> <th>Variable</th> <th>Value</th> </tr> </thead> <tbody> <% req.POST.sort_by { |k, v| k.to_s }.each { |key, val| %> <tr> <td><%=h key %></td> <td class="code"><div><%=h val.inspect %></div></td> </tr> <% } %> </tbody> </table> <% else %> <p><%= no_post_data || "No POST data" %>.</p> <% end %> <h3 id="cookie-info">COOKIES</h3> <% unless req.cookies.empty? %> <table class="req"> <thead> <tr> <th>Variable</th> <th>Value</th> </tr> </thead> <tbody> <% req.cookies.each { |key, val| %> <tr> <td><%=h key %></td> <td class="code"><div><%=h val.inspect %></div></td> </tr> <% } %> </tbody> </table> <% else %> <p>No cookie data.</p> <% end %> <h3 id="env-info">Rack ENV</h3> <table class="req"> <thead> <tr> <th>Variable</th> <th>Value</th> </tr> </thead> <tbody> <% env.sort_by { |k, v| k.to_s }.each { |key, val| %> <tr> <td><%=h key %></td> <td class="code"><div><%=h val.inspect %></div></td> </tr> <% } %> </tbody> </table> </div> <div id="explanation"> <p> You're seeing this error because you use <code>Rack::ShowExceptions</code>. </p> </div> </body> </html> HTML
Instance Method Summary collapse
- #call(env) ⇒ Object
- #dump_exception(exception) ⇒ Object
-
#h(obj) ⇒ Object
:nodoc:.
-
#initialize(app) ⇒ ShowExceptions
constructor
A new instance of ShowExceptions.
- #prefers_plaintext?(env) ⇒ Boolean
- #pretty(env, exception) ⇒ Object
- #template ⇒ Object
Constructor Details
#initialize(app) ⇒ ShowExceptions
Returns a new instance of ShowExceptions.
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# File 'lib/rack/show_exceptions.rb', line 27 def initialize(app) @app = app end |
Instance Method Details
#call(env) ⇒ Object
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# File 'lib/rack/show_exceptions.rb', line 31 def call(env) @app.call(env) rescue StandardError, LoadError, SyntaxError => e exception_string = dump_exception(e) env[RACK_ERRORS].puts(exception_string) env[RACK_ERRORS].flush if accepts_html?(env) content_type = "text/html" body = pretty(env, e) else content_type = "text/plain" body = exception_string end [ 500, { CONTENT_TYPE => content_type, CONTENT_LENGTH => body.bytesize.to_s, }, [body], ] end |
#dump_exception(exception) ⇒ Object
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# File 'lib/rack/show_exceptions.rb', line 66 def dump_exception(exception) if exception.respond_to?(:detailed_message) = exception.(highlight: false) else = exception. end string = "#{exception.class}: #{}\n".dup string << exception.backtrace.map { |l| "\t#{l}" }.join("\n") string end |
#h(obj) ⇒ Object
:nodoc:
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# File 'lib/rack/show_exceptions.rb', line 117 def h(obj) # :nodoc: case obj when String Utils.escape_html(obj) else Utils.escape_html(obj.inspect) end end |
#prefers_plaintext?(env) ⇒ Boolean
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# File 'lib/rack/show_exceptions.rb', line 57 def prefers_plaintext?(env) !accepts_html?(env) end |
#pretty(env, exception) ⇒ Object
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# File 'lib/rack/show_exceptions.rb', line 77 def pretty(env, exception) req = Rack::Request.new(env) # This double assignment is to prevent an "unused variable" warning. # Yes, it is dumb, but I don't like Ruby yelling at me. path = path = (req.script_name + req.path_info).squeeze("/") # This double assignment is to prevent an "unused variable" warning. # Yes, it is dumb, but I don't like Ruby yelling at me. frames = frames = exception.backtrace.map { |line| frame = Frame.new if line =~ /(.*?):(\d+)(:in `(.*)')?/ frame.filename = $1 frame.lineno = $2.to_i frame.function = $4 begin lineno = frame.lineno - 1 lines = ::File.readlines(frame.filename) frame.pre_context_lineno = [lineno - CONTEXT, 0].max frame.pre_context = lines[frame.pre_context_lineno...lineno] frame.context_line = lines[lineno].chomp frame.post_context_lineno = [lineno + CONTEXT, lines.size].min frame.post_context = lines[lineno + 1..frame.post_context_lineno] rescue end frame else nil end }.compact template.result(binding) end |
#template ⇒ Object
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# File 'lib/rack/show_exceptions.rb', line 113 def template TEMPLATE end |