refactored pattern layout

lib/layouts.js

@@ -169,6 +169,125 @@ function patternLayout (pattern, tokens) {
   var regex = /%(-?[0-9]+)?(\.?[0-9]+)?([\[\]cdmnprx%])(\{([^\}]+)\})?|([^%]+)/;
   
   pattern = pattern || TTCC_CONVERSION_PATTERN;
+
+  function categoryName(loggingEvent, specifier) {
+    var loggerName = loggingEvent.categoryName;
+    if (specifier) {
+      var precision = parseInt(specifier, 10);
+      var loggerNameBits = loggerName.split(".");
+      if (precision < loggerNameBits.length) {
+        loggerName = loggerNameBits.slice(loggerNameBits.length - precision).join(".");
+      }
+    }
+    return loggerName;
+  }
+
+  function formatAsDate(loggingEvent, specifier) {
+    var format = dateFormat.ISO8601_FORMAT;
+    if (specifier) {
+      format = specifier;
+      // Pick up special cases
+      if (format == "ISO8601") {
+        format = dateFormat.ISO8601_FORMAT;
+      } else if (format == "ABSOLUTE") {
+        format = dateFormat.ABSOLUTETIME_FORMAT;
+      } else if (format == "DATE") {
+        format = dateFormat.DATETIME_FORMAT;
+      }
+    }
+    // Format the date
+    return dateFormat.asString(format, loggingEvent.startTime);
+  }
+
+  function formatMessage(loggingEvent) {
+    return formatLogData(loggingEvent.data);
+  }
+  
+  function endOfLine() {
+    return eol;
+  }
+
+  function logLevel(loggingEvent) {
+    return loggingEvent.level.toString();
+  }
+
+  function startTime(loggingEvent) {
+    return "" + loggingEvent.startTime.toLocaleTimeString();
+  }
+
+  function startColour(loggingEvent) {
+    return colorizeStart(colours[loggingEvent.level.toString()]);
+  }
+
+  function endColour(loggingEvent) {
+    return colorizeEnd(colours[loggingEvent.level.toString()]);
+  }
+
+  function percent() {
+    return '%';
+  }
+
+  function userDefined(loggingEvent, specifier) {
+    if (typeof(tokens[specifier]) !== 'undefined') {
+      if (typeof(tokens[specifier]) === 'function') {
+        return tokens[specifier](loggingEvent);
+      } else {
+        return tokens[specifier];
+      }
+    }
+    return null;
+  }
+
+  var replacers = {
+    'c': categoryName,
+    'd': formatAsDate,
+    'm': formatMessage,
+    'n': endOfLine,
+    'p': logLevel,
+    'r': startTime,
+    '[': startColour,
+    ']': endColour,
+    '%': percent,
+    'x': userDefined
+  };
+
+  function replaceToken(conversionCharacter, loggingEvent, specifier) {
+    var replacer = replacers[conversionCharacter];
+    if (replacer) {
+      return replacer(loggingEvent, specifier);
+    }
+    return null;
+  }
+
+  function truncate(truncation, toTruncate) {
+    var len;
+    if (truncation) {
+      len = parseInt(truncation.substr(1), 10);
+      return toTruncate.substring(0, len);
+    }
+
+    return toTruncate;
+  }
+
+  function pad(padding, toPad) {
+    var len;
+    if (padding) {
+      if (padding.charAt(0) == "-") {
+        len = parseInt(padding.substr(1), 10);
+        // Right pad with spaces
+        while (toPad.length < len) {
+          toPad += " ";
+        }
+      } else {
+        len = parseInt(padding, 10);
+        // Left pad with spaces
+        while (toPad.length < len) {
+          toPad = " " + toPad;
+        }
+      }
+    }
+    return toPad;
+  }
   
   return function(loggingEvent) {
     var formattedString = "";
@@ -189,100 +308,14 @@ function patternLayout (pattern, tokens) {
       } else {
         // Create a raw replacement string based on the conversion
         // character and specifier
-        var replacement = "";
-        switch(conversionCharacter) {
-        case "c":
-          var loggerName = loggingEvent.categoryName;
-          if (specifier) {
-            var precision = parseInt(specifier, 10);
-            var loggerNameBits = loggingEvent.categoryName.split(".");
-            if (precision >= loggerNameBits.length) {
-              replacement = loggerName;
-            } else {
-              replacement = loggerNameBits.slice(loggerNameBits.length - precision).join(".");
-            }
-          } else {
-            replacement = loggerName;
-          }
-          break;
-        case "d":
-          var format = dateFormat.ISO8601_FORMAT;
-          if (specifier) {
-            format = specifier;
-            // Pick up special cases
-            if (format == "ISO8601") {
-              format = dateFormat.ISO8601_FORMAT;
-            } else if (format == "ABSOLUTE") {
-              format = dateFormat.ABSOLUTETIME_FORMAT;
-            } else if (format == "DATE") {
-              format = dateFormat.DATETIME_FORMAT;
-            }
-          }
-          // Format the date
-          replacement = dateFormat.asString(format, loggingEvent.startTime);
-          break;
-        case "m":
-          replacement = formatLogData(loggingEvent.data);
-          break;
-        case "n":
-          replacement = eol;
-          break;
-        case "p":
-          replacement = loggingEvent.level.toString();
-          break;
-        case "r":
-          replacement = "" + loggingEvent.startTime.toLocaleTimeString();
-          break;
-        case "[":
-          replacement = colorizeStart(colours[loggingEvent.level.toString()]);
-          break;
-        case "]":
-          replacement = colorizeEnd(colours[loggingEvent.level.toString()]);
-          break;
-        case "%":
-          replacement = "%";
-          break;
-        case "x":
-          if(typeof(tokens[specifier]) !== 'undefined') {
-            if(typeof(tokens[specifier]) === 'function') {
-              replacement = tokens[specifier]();
-            } else {
-              replacement = tokens[specifier];
-            }
-          } else {
-            replacement = matchedString;
-          }
-          break;
-        default:
-          replacement = matchedString;
-          break;
-        }
+        var replacement = 
+          replaceToken(conversionCharacter, loggingEvent, specifier) || 
+          matchedString;
+
         // Format the replacement according to any padding or
         // truncation specified
-        
-        var len;
-        
-        // First, truncation
-        if (truncation) {
-          len = parseInt(truncation.substr(1), 10);
-          replacement = replacement.substring(0, len);
-        }
-        // Next, padding
-        if (padding) {
-          if (padding.charAt(0) == "-") {
-            len = parseInt(padding.substr(1), 10);
-            // Right pad with spaces
-            while (replacement.length < len) {
-              replacement += " ";
-            }
-          } else {
-            len = parseInt(padding, 10);
-            // Left pad with spaces
-            while (replacement.length < len) {
-              replacement = " " + replacement;
-            }
-          }
-        }
+        replacement = truncate(truncation, replacement);
+        replacement = pad(padding, replacement);
         formattedString += replacement;
       }
       searchString = searchString.substr(result.index + result[0].length);