def getUniqueValues(layer,field):
    """  

    Parameters
    ----------
    layer (vector layer): The layer to compute on
    field (String):Name of field to calculate unique values from

    Returns
    -------
    List

    """
    
    values=[]
    for feature in layer.getFeatures():
        if feature[field] not in values:
            values.append(feature[field])
    values.sort()
    return values