Basic structure for format constraint

include/valijson/constraints/concrete_constraints.hpp

@@ -427,6 +427,33 @@ private:
     EnumValues m_enumValues;
 };
 
+/**
+ * @brief  Represent a 'format' constraint
+ *
+ * A format constraint restricts the content of string values, as defined by a set of commonly used formats.
+ *
+ * As this is an optional feature in JSON Schema, unrecognised formats will be treated as valid for any string value.
+ */
+class FormatConstraint: public BasicConstraint<FormatConstraint>
+{
+public:
+    FormatConstraint()
+        : m_format() { }
+
+    const std::string & getFormat() const
+    {
+        return m_format;
+    }
+
+    void setFormat(const std::string & format)
+    {
+        m_format = format;
+    }
+
+private:
+    std::string m_format;
+};
+
 /**
  * @brief  Represents non-singular 'items' and 'additionalItems' constraints
  *

include/valijson/constraints/constraint_visitor.hpp

@@ -10,6 +10,7 @@ class ConstConstraint;
 class ContainsConstraint;
 class DependenciesConstraint;
 class EnumConstraint;
+class FormatConstraint;
 class LinearItemsConstraint;
 class MaxItemsConstraint;
 class MaximumConstraint;
@@ -46,6 +47,7 @@ protected:
     typedef constraints::ContainsConstraint ContainsConstraint;
     typedef constraints::DependenciesConstraint DependenciesConstraint;
     typedef constraints::EnumConstraint EnumConstraint;
+    typedef constraints::FormatConstraint FormatConstraint;
     typedef constraints::LinearItemsConstraint LinearItemsConstraint;
     typedef constraints::MaximumConstraint MaximumConstraint;
     typedef constraints::MaxItemsConstraint MaxItemsConstraint;
@@ -77,6 +79,7 @@ public:
     virtual bool visit(const ContainsConstraint &) = 0;
     virtual bool visit(const DependenciesConstraint &) = 0;
     virtual bool visit(const EnumConstraint &) = 0;
+    virtual bool visit(const FormatConstraint &) = 0;
     virtual bool visit(const LinearItemsConstraint &) = 0;
     virtual bool visit(const MaximumConstraint &) = 0;
     virtual bool visit(const MaxItemsConstraint &) = 0;

include/valijson/schema_parser.hpp

@@ -694,6 +694,10 @@ private:
             rootSchema.addConstraintToSubschema(makeEnumConstraint(itr->second), &subschema);
         }
 
+        if ((itr = object.find("format")) != object.end()) {
+            rootSchema.addConstraintToSubschema(makeFormatConstraint(itr->second), &subschema);
+        }
+
         {
             const typename AdapterType::Object::const_iterator itemsItr =
                     object.find("items");
@@ -1421,6 +1425,24 @@ private:
         return constraint;
     }
 
+    /**
+     * @brief   Make a new FormatConstraint object
+     *
+     * @param   node  JSON node containing the configuration for this constraint
+     *
+     * @return  pointer to a new FormatConstraint that belongs to the caller
+     */
+    template<typename AdapterType>
+    constraints::FormatConstraint makeFormatConstraint(
+        const AdapterType &node)
+    {
+        constraints::FormatConstraint constraint;
+
+        // TODO
+
+        return constraint;
+    }
+
     /**
      * @brief   Make a new ItemsConstraint object.
      *

include/valijson/validation_visitor.hpp

@@ -347,6 +347,20 @@ public:
         return numValidated > 0;
     }
 
+    /**
+     * @brief   Validate current node against a FormatConstraint
+     *
+     * @param   constraint  Constraint that the target must validate against
+     *
+     * @return  \c true if validation succeeds; \c false otherwise
+     */
+    bool visit(const FormatConstraint &constraint) override
+    {
+        // TODO
+
+        return true;
+    }
+
     /**
      * @brief   Validate a value against a LinearItemsConstraint
      *