Refactor|libdeng2: String pattern formatting moved to its own method

Pattern formatting does not belong in LogEntry::asText(). Also fixed a bug in detecting an escaped format character (%%).
skyjake · Mar 22, 2013 · ce33ba0 · ce33ba0
1 parent c35d942
commit ce33ba0
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Showing 4 changed files with 66 additions and 37 deletions.
diff --git a/doomsday/libdeng2/include/de/core/log.h b/doomsday/libdeng2/include/de/core/log.h
@@ -310,9 +310,6 @@ class DENG2_PUBLIC LogEntry : public Lockable, public ISerializable
     };
     Q_DECLARE_FLAGS(Flags, Flag)
 
-    /// The format string has incorrect syntax. @ingroup errors
-    DENG2_ERROR(IllegalFormatError);
-
     typedef QList<Arg *> Args;
 
 public:

diff --git a/doomsday/libdeng2/include/de/data/string.h b/doomsday/libdeng2/include/de/data/string.h
@@ -21,6 +21,7 @@
 #define LIBDENG2_STRING_H
 
 #include <QString>
+#include <QList>
 
 #include "../libdeng2.h"
 #include "../Block"
@@ -68,6 +69,8 @@ class DENG2_PUBLIC String : public QString
         virtual ddouble asNumber() const = 0;
     };
 
+    typedef QList<IPatternArg const *> PatternArgs;
+
     typedef dint size_type;
 
 public:
@@ -130,6 +133,16 @@ class DENG2_PUBLIC String : public QString
      */
     String operator / (String const &path) const;
 
+    /**
+     * Applies pattern formatting using the string as a format string.
+     *
+     * @param args  List of arguments.
+     *
+     * @return String with placeholders replaced using the arguments.
+     * @see patternFormat()
+     */
+    String operator % (PatternArgs args) const;
+
     /**
      * Does a record member concatenation on a variable name. Record members
      * use '.' as the separator character.

diff --git a/doomsday/libdeng2/src/core/log.cpp b/doomsday/libdeng2/src/core/log.cpp
@@ -372,32 +372,9 @@ String LogEntry::asText(Flags const &formattingFlags, int shortenSection) const
     }
     else
     {
-        Args::const_iterator arg = _args.begin();
-
-        DENG2_FOR_EACH_CONST(String, i, _format)
-        {
-            if(*i == '%')
-            {
-                if(arg == _args.end())
-                {
-                    // Out of args.
-                    throw IllegalFormatError("LogEntry::asText", "Ran out of arguments");
-                }
-
-                output << String::patternFormat(i, _format.end(), **arg);
-                ++arg;
-            }
-            else
-            {
-                output << *i;
-            }
-        }
-
-        // Just append the rest of the arguments without special instructions.
-        for(; arg != _args.end(); ++arg)
-        {
-            output << **arg;
-        }        
+        String::PatternArgs patArgs;
+        DENG2_FOR_EACH_CONST(Args, i, _args) patArgs << *i;
+        output << _format % patArgs;
     }
 
     if(flags & Styled)

diff --git a/doomsday/libdeng2/src/data/string.cpp b/doomsday/libdeng2/src/data/string.cpp
@@ -98,6 +98,51 @@ String String::operator / (String const &path) const
     return concatenatePath(path);
 }
 
+String String::operator % (PatternArgs args) const
+{
+    String result;
+    QTextStream output(&result);
+
+    PatternArgs::const_iterator arg = args.begin();
+
+    DENG2_FOR_EACH_CONST(String, i, *this)
+    {
+        if(*i == '%')
+        {
+            String::const_iterator next = i;
+            advanceFormat(next, end());
+            if(*next == '%')
+            {
+                // Escaped.
+                output << *next;
+                ++i;
+                continue;
+            }
+
+            if(arg == args.end())
+            {
+                // Out of args.
+                throw IllegalPatternError("String::operator %", "Ran out of arguments");
+            }
+
+            output << patternFormat(i, end(), **arg);
+            ++arg;
+        }
+        else
+        {
+            output << *i;
+        }
+    }
+
+    // Just append the rest of the arguments without special instructions.
+    for(; arg != args.end(); ++arg)
+    {
+        output << (*arg)->asText();
+    }
+
+    return result;
+}
+
 String String::concatenatePath(String const &other, QChar dirChar) const
 {
     if(QDir::isAbsolutePath(other))
@@ -425,16 +470,16 @@ String String::patternFormat(String::const_iterator &formatIter,
 {
     advanceFormat(formatIter, formatEnd);
 
+    QString result;
+    QTextStream output(&result);
+
     // An argument comes here.
     bool rightAlign = true;
     dint maxWidth = 0;
     dint minWidth = 0;
 
-    if(*formatIter == '%')
-    {
-        // Escaped.
-        return String(1, *formatIter);
-    }
+    DENG2_ASSERT(*formatIter != '%');
+
     if(*formatIter == '-')
     {
         // Left aligned.
@@ -464,9 +509,6 @@ String String::patternFormat(String::const_iterator &formatIter,
     }
 
     // Finally, the type formatting.
-    QString result;
-    QTextStream output(&result);
-
     switch((*formatIter).toLatin1())
     {
     case 's':