/// <summary>
/// Walks JSON tokens and validates and fires events on the supplied events instance.
/// </summary>
/// <param name="tokens"></param>
/// <param name="events"></param>
public void Walk(JSONTokenStream tokens, JSONWalkingEvents events)
{
_Start(tokens, events);
tokens.MoveNext();
if (JSONTokenType.EOF != tokens.Current.Type)
{
throw new JSONValidationException("Expected EOF but got: " + tokens.Current.Type);
}
}
/// <summary>
/// Reads an Array. Fires ArrayStart, ArrayNext, and ArrayEnd.
/// </summary>
/// <param name="tokens"></param>
/// <param name="events"></param>
private void _Array(JSONTokenStream tokens, JSONWalkingEvents events)
{
if (null != events)
{
events.RaiseArrayStart();
}
tokens.MoveNext();
JSONToken next = tokens.Current;
while (JSONTokenType.ARRAY_END != next.Type)
{
_ArrayElement(tokens, events);
tokens.MoveNext();
next = tokens.Current;
if (JSONTokenType.COMMA == next.Type)
{
tokens.MoveNext();
next = tokens.Current;
if (null != events)
{
events.RaiseArrayNext();
}
}
}
if (JSONTokenType.ARRAY_END == next.Type)
{
if (null != events)
{
events.RaiseArrayEnd();
}
return;
}
else
{
throw new JSONValidationException("Expected VALUE or end of ARRAY but got: " + next.Type);
}
}
/// <summary>
/// Start walking the JSON structure.
/// </summary>
/// <param name="tokens"></param>
/// <param name="events"></param>
private void _Start(JSONTokenStream tokens, JSONWalkingEvents events)
{
tokens.MoveNext();
JSONToken next = tokens.Current;
if (JSONTokenType.OBJECT_START == next.Type)
{
_Object(tokens, events);
}
else if (JSONTokenType.ARRAY_START == next.Type)
{
_Array(tokens, events);
}
else
{
throw new JSONValidationException("Expected OBJECT or ARRAY but got: " + next.Type);
}
}
/// <summary>
/// Walk an Object. Fires ObjectStart, ObjectKey, ObjectNext, and ObjectEnd
/// </summary>
/// <param name="tokens"></param>
/// <param name="events"></param>
private void _Object(JSONTokenStream tokens, JSONWalkingEvents events)
{
if (null != events)
{
events.RaiseObjectStart();
}
tokens.MoveNext();
JSONToken next = tokens.Current;
while (JSONTokenType.OBJECT_END != next.Type)
{
_ObjectField(tokens, events);
tokens.MoveNext();
next = tokens.Current;
if (JSONTokenType.COMMA == next.Type)
{
tokens.MoveNext();
next = tokens.Current;
if (null != events)
{
events.RaiseObjectNext();
}
}
}
if (JSONTokenType.OBJECT_END == next.Type)
{
if (null != events)
{
events.RaiseObjectEnd();
}
return;
}
else
{
throw new JSONValidationException("Expected VALUE or end of OBJECT but got: " + next.Type);
}
}
private void _ObjectField(JSONTokenStream tokens, JSONWalkingEvents events)
{
JSONToken next = tokens.Current;
if (JSONTokenType.STRING == next.Type)
{
if (null != events)
{
events.RaiseObjectKey(next.StrValue);
}
tokens.MoveNext();
next = tokens.Current;
if (JSONTokenType.COLON == next.Type)
{
tokens.MoveNext();
next = tokens.Current;
switch (next.Type)
{
case JSONTokenType.STRING:
if (null != events)
{
events.RaiseString(next.StrValue);
}
break;
case JSONTokenType.NUMBER:
if (null != events)
{
events.RaiseNumber(next.NumValue);
}
break;
case JSONTokenType.KEYWORD_TRUE:
if (null != events)
{
events.RaiseBoolean(true);
}
break;
case JSONTokenType.KEYWORD_FALSE:
if (null != events)
{
events.RaiseBoolean(false);
}
break;
case JSONTokenType.KEYWORD_NULL:
if (null != events)
{
events.RaiseNull();
}
break;
case JSONTokenType.OBJECT_START:
_Object(tokens, events);
break;
case JSONTokenType.ARRAY_START:
_Array(tokens, events);
break;
default:
throw new JSONValidationException("Expected value but got: " + next.Type);
}
}
else
{
throw new JSONValidationException("Expected COLON but got: " + next.Type);
}
}
else
{
throw new JSONValidationException("Expected STRING but got: " + next.Type);
}
}
public JSONSelector(JSONWalkingEvents events, string[] paths, JSONSelectorOptions options)
{
if (null == events)
{
throw new ArgumentNullException("events");
}
_events = events;
paths = paths ?? new string[0];
if (options.IgnoreArrays())
{
// Filter out paths containing array specifiers
_paths = paths.Where(p => -1 == p.IndexOf(ArraySpecifier))
.ToDictionary<string, string>(p => p);
}
else
{
_paths = paths.ToDictionary<string, string>(p => p);
}
_selectedValues = new List<SelectedValue>();
_options = options;
_objectPathStack = new Stack<string>();
_objectPath = string.Empty;
_memberPath = string.Empty;
_arrayIndex = -1;
_arrayIndexStack = new Stack<int>();
_events.ObjectStart += new JSONEventHandler(_events_ObjectStart);
_events.ObjectEnd += new JSONEventHandler(_events_ObjectEnd);
_events.ObjectKey += new JSONEventHandler<string>(_events_ObjectKey);
_events.ArrayStart += new JSONEventHandler(_events_ArrayStart);
_events.ArrayEnd += new JSONEventHandler(_events_ArrayEnd);
_events.ArrayNext += new JSONEventHandler(_events_ArrayNext);
_events.String += new JSONEventHandler<string>(_events_String);
_events.Number += new JSONEventHandler<decimal>(_events_Number);
_events.Null += new JSONEventHandler(_events_Null);
_events.Boolean += new JSONEventHandler<bool>(_events_Boolean);
}
public JSONSelector(JSONWalkingEvents events, string[] paths)
: this(events, paths, DefaultOptions)
{
}
public static SelectedValue[] SelectValues(TextReader json, string[] selectors, JSONSelectorOptions options)
{
if (null == json)
{
return new SelectedValue[0];
}
// Create tokenizer for the JSON text - this is fed to a Tree Walking Validator
JSONTokenizer tokenizer = new JSONTokenizer(json);
// Create an events object for the Tree Walker - events are fired as the walker
// traverses nodes in the tree.
JSONWalkingEvents events = new JSONWalkingEvents();
// The selector subscribes to the Walker Events and selects the appropriate values from the
// JSON tree.
JSONSelector selector = new JSONSelector(events, selectors);
// A JSON Tree Walker that validates the structure of the JSON and also fires events
// while traversing the tree.
JSONWalkingValidator walker = new JSONWalkingValidator();
walker.Walk(tokenizer.GetEnumerator(), events);
// Retrieve the values selected from the JSON.
return selector.SelectedValues;
}
public static SQLConstraint GenerateSQLConstraint(IDatabaseService db, Dictionary<string, Type> typeMappings, string json)
{
var tokenizer = new JSONTokenizer(new StringReader(json));
var events = new JSONWalkingEvents();
var constraint = new JSONToSQLConstraint(db, events, typeMappings);
JSONWalkingValidator walker = new JSONWalkingValidator();
walker.Walk(tokenizer.GetEnumerator(), events);
return constraint.GenerateSQLConstraint();
}
public JSONToSQLConstraint(IDatabaseService db, JSONWalkingEvents events, Dictionary<string, Type> typeMappings)
{
if (null == db)
{
throw new ArgumentNullException("db");
}
if (null == events)
{
throw new ArgumentNullException("events");
}
if (null == typeMappings)
{
throw new ArgumentNullException("typeMappings");
}
_db = db;
_events = events;
_typeMappings = typeMappings;
_events.ObjectStart += new JSONEventHandler(_events_ObjectStart);
_events.ObjectEnd += new JSONEventHandler(_events_ObjectEnd);
_events.ObjectKey += new JSONEventHandler<string>(_events_ObjectKey);
_events.ArrayStart += new JSONEventHandler(_events_ArrayStart);
_events.ArrayEnd += new JSONEventHandler(_events_ArrayEnd);
_events.ArrayNext += new JSONEventHandler(_events_ArrayNext);
_events.String += new JSONEventHandler<string>(_events_String);
_events.Number += new JSONEventHandler<decimal>(_events_Number);
_events.Null += new JSONEventHandler(_events_Null);
_events.Boolean += new JSONEventHandler<bool>(_events_Boolean);
_constraints = new Stack<Constraint>();
}
