nicer way to create bson

BSONField<int> x("x"); BSONObj o = BSON( x(5) ); ASSERT_EQUALS( BSON( "x" << 5 ) , o ); o = BSON( x.gt(5) ); ASSERT_EQUALS( BSON( "x" << BSON( "$gt" << 5 ) ) , o );
mongodb · Jun 21, 2010 · a7f063d · a7f063d
1 parent 66bdde3
commit a7f063d
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Showing 3 changed files with 90 additions and 0 deletions.
diff --git a/bson/bsoninlines.h b/bson/bsoninlines.h
@@ -572,4 +572,11 @@ namespace mongo {
     }
 
     inline void BSONElement::Val(BSONObj& v) const { v = Obj(); }
+
+    template<typename T>
+    inline BSONFieldValue<BSONObj> BSONField<T>::query( const char * q , const T& t ) const {
+        BSONObjBuilder b;
+        b.append( q , t );
+        return BSONFieldValue<BSONObj>( _name , b.obj() );
+    }
 }
diff --git a/bson/bsonobjbuilder.h b/bson/bsonobjbuilder.h
@@ -33,6 +33,48 @@ namespace mongo {
 #pragma warning( disable : 4355 )
 #endif
 
+    template<typename T>
+    class BSONFieldValue {
+    public:
+        BSONFieldValue( const string& name , const T& t ){
+            _name = name;
+            _t = t;
+        }
+
+        const T& value() const { return _t; }
+        const string& name() const { return _name; }
+
+    private:
+        string _name;
+        T _t;
+    };
+
+    template<typename T>
+    class BSONField {
+    public:
+        BSONField( const string& name , const string& longName="" ) 
+            : _name(name), _longName(longName){}
+        const string& name() const { return _name; }
+        operator string() const { return _name; }
+
+        BSONFieldValue<T> make( const T& t ) const {
+            return BSONFieldValue<T>( _name , t );
+        }
+
+        BSONFieldValue<BSONObj> gt( const T& t ) const { return query( "$gt" , t ); }
+        BSONFieldValue<BSONObj> lt( const T& t ) const { return query( "$lt" , t ); }
+
+        BSONFieldValue<BSONObj> query( const char * q , const T& t ) const;
+
+        BSONFieldValue<T> operator()( const T& t ) const {
+            return BSONFieldValue<T>( _name , t );
+        }
+
+    private:
+        string _name;
+        string _longName;
+    };
+
     /** Utility for creating a BSONObj.
         See also the BSON() and BSON_ARRAY() macros.
     */
@@ -527,6 +569,19 @@ namespace mongo {
             return _s << l;
         }
 
+        template<typename T>
+        BSONObjBuilderValueStream& operator<<( const BSONField<T>& f ) {
+            _s.endField( f.name().c_str() );
+            return _s;
+        } 
+
+        template<typename T>
+        BSONObjBuilder& operator<<( const BSONFieldValue<T>& v ) {
+            append( v.name().c_str() , v.value() );
+            return *this;
+        } 
+
+
         /** @return true if we are using our own bufbuilder, and not an alternate that was given to us in our constructor */
         bool owned() const { return &_b == &_buf; }
 

diff --git a/dbtests/jsobjtests.cpp b/dbtests/jsobjtests.cpp
@@ -1512,6 +1512,33 @@ namespace JsobjTests {
         }
     };
 
+    class BSONFieldTests {
+    public:
+        void run(){
+            {
+                BSONField<int> x("x");
+                BSONObj o = BSON( x << 5 );
+                ASSERT_EQUALS( BSON( "x" << 5 ) , o );
+            }
+
+            {
+                BSONField<int> x("x");
+                BSONObj o = BSON( x.make(5) );
+                ASSERT_EQUALS( BSON( "x" << 5 ) , o );
+            }
+
+            {
+                BSONField<int> x("x");
+                BSONObj o = BSON( x(5) );
+                ASSERT_EQUALS( BSON( "x" << 5 ) , o );
+
+                o = BSON( x.gt(5) );
+                ASSERT_EQUALS( BSON( "x" << BSON( "$gt" << 5 ) ) , o );
+            }
+
+        }
+    };
+
     class All : public Suite {
     public:
         All() : Suite( "jsobj" ){
@@ -1607,6 +1634,7 @@ namespace JsobjTests {
             add< ElementSetTest >();
             add< EmbeddedNumbers >();
             add< BuilderPartialItearte >();
+            add< BSONFieldTests >();
         }
     } myall;