protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
_songViewModel = validationContext.ObjectInstance as SongViewModel;
_midiFileHandler = _songViewModel?.MidiFileHandler;
_chordsFileHandler = _songViewModel?.ChordsFileHandler;
_melodyTrackIndex = _songViewModel?.MelodyTrackIndex;
// nothing to check if no file is uploaded for current file handler property
if (value == null)
{
return(ValidationResult.Success);
}
else
{
_fileHandler = value as HttpPostedFileBase;
}
// set the subjected validated file type according to the subject file handler
if (_fileHandler == _midiFileHandler)
{
_songFileType = SongFileType.MidiOriginalFile;
}
else
{
_songFileType = SongFileType.ChordProgressionFile;
}
// validate file metadata (size, mime type, etc)
if (!FileUploadValidation.IsFileMetadataValid(_fileHandler, _songFileType, out _errorMessage))
{
return(new ValidationResult(_errorMessage));
}
// fetch chords data from new chords file or from existing db record
if (_chordsFileHandler != null)
{
if (!IsChordsFileValid(_chordsFileHandler, _songFileType, out _bars, out _errorMessage))
{
return(new ValidationResult(_errorMessage));
}
}
// validations for MIDI progression file
if (_songFileType == SongFileType.MidiOriginalFile)
{
if (!FileUploadValidation.IsMidiFileValid(_midiFileHandler, out _midi, out _errorMessage))
{
return(new ValidationResult(_errorMessage));
}
}
// aditional validation for midi file and midi vs chords file
if (_fileHandler == _midiFileHandler)
{
// validate melody track index is not out of bounds
if (!CompositionContext.IsMelodyTrackIndexValid((int?)_melodyTrackIndex, _midi, out _errorMessage))
{
return(new ValidationResult(_errorMessage));
}
// validate that bars in CHORD progression are compatible with MIDI file
if (!CompositionContext.AreBarsCompatible(_bars, _midi, out _errorMessage))
{
return(new ValidationResult(_errorMessage));
}
}
// if we got this far then hopefully everything is okay
return(ValidationResult.Success);
}