functionObjects::writeObjects: Added option "writeOption"

Description
    Allows specification of different writing frequency of objects registered
    to the database.

    It has similar functionality as the main time database through the
    \c writeControl setting:
      - timeStep
      - writeTime
      - adjustableRunTime
      - runTime
      - clockTime
      - cpuTime

    It also has the ability to write the selected objects that were defined
    with the respective write mode for the requested \c writeOption, namely:
      - \c autoWrite - objects set to write at output time
      - \c noWrite   - objects set to not write by default
      - \c anyWrite  - any option of the previous two

    Example of function object specification:
    \verbatim
    writeObjects1
    {
        type        writeObjects;
        libs        ("libutilityFunctionObjects.so");
        ...
        objects     (obj1 obj2);
        writeOption anyWrite;
    }
    \endverbatim

Patch contributed by Bruno Santos
Resolves bug-report http://bugs.openfoam.org/view.php?id=2090

src/functionObjects/utilities/writeObjects/writeObjects.C

@@ -42,9 +42,24 @@ namespace functionObjects
         writeObjects,
         dictionary
     );
+
+    template<>
+    const char* Foam::NamedEnum
+    <
+        Foam::functionObjects::writeObjects::writeOption,
+        3
+    >::names[] =
+    {
+        "autoWrite",
+        "noWrite",
+        "anyWrite"
+    };
 }
 }
 
+const Foam::NamedEnum<Foam::functionObjects::writeObjects::writeOption, 3>
+    Foam::functionObjects::writeObjects::writeOptionNames;
+
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
@@ -63,7 +78,7 @@ Foam::functionObjects::writeObjects::writeObjects
             dict.lookupOrDefault("region", polyMesh::defaultRegion)
         )
     ),
-    exclusiveWriting_(false),
+    writeOption_(ANY_WRITE),
     objectNames_()
 {
     read(dict);
@@ -94,7 +109,14 @@ bool Foam::functionObjects::writeObjects::read(const dictionary& dict)
         dict.lookup("objects") >> objectNames_;
     }
 
-    dict.readIfPresent("exclusiveWriting", exclusiveWriting_);
+    if (dict.found("writeOption"))
+    {
+        writeOption_ = writeOptionNames.read(dict.lookup("writeOption"));
+    }
+    else
+    {
+        writeOption_ = ANY_WRITE;
+    }
 
     return true;
 }
@@ -140,15 +162,49 @@ bool Foam::functionObjects::writeObjects::write()
             obr_.lookupObject<regIOobject>(allNames[i])
         );
 
-        if (exclusiveWriting_)
+        switch(writeOption_)
         {
-            // Switch off automatic writing to prevent double write
-            obj.writeOpt() = IOobject::NO_WRITE;
+            case AUTO_WRITE:
+                if (obj.writeOpt() != IOobject::AUTO_WRITE)
+                {
+                    continue;
+                }
+                else
+                {
+                    break;
+                }
+
+            case NO_WRITE:
+                if (obj.writeOpt() != IOobject::NO_WRITE)
+                {
+                    continue;
+                }
+                else
+                {
+                    break;
+                }
+
+            case ANY_WRITE:
+                break;
+
+            default:
+                continue;
         }
 
-        Info<< "    writing object " << obj.name() << endl;
+        if
+        (
+            obj.writeOpt() == IOobject::AUTO_WRITE
+         && obr_.time().writeTime()
+        )
+        {
+            Info<< "    automatically written object " << obj.name() << endl;
+        }
+        else
+        {
+            Info<< "    writing object " << obj.name() << endl;
 
-        obj.write();
+            obj.write();
+        }
     }
 
     return true;