/// <summary>
/// this method evaluates the formula stored in the contents of the selected cell
/// </summary>
/// <param name="cellColumn"></param>
/// <param name="cellRow"></param>
/// <returns></returns>
private object evaluateFormula(int cellColumn, int cellRow)
{
//storing the empty string
object result = "";
//getting the value of the previous cell
bool passed = spreadsheetPanel1.GetValue(prevCol, prevRow, out string prevContent);
//storing the previous contents
object previousContent = prevContent;
ISet <string> list = new HashSet <string>();
//if the previous contents was a formula
if (prevContent.StartsWith("="))
{
//surround in a try catch to catch different exceptions
try
{
//getting the dependent cells and putting them in a list
list = formSpreadsheet.SetContentsOfCell(asciiConverter(cellColumn, cellRow), prevContent);
//calculating the value of the selected cell
result = formSpreadsheet.calculateValue(asciiConverter(cellColumn, cellRow));
//evaluating all the cells in the given list
reEvaluateValues(list);
}
//if a circular exception is thrown
catch (CircularException)
{
int col;
int row;
spreadsheetPanel1.GetSelection(out col, out row);
//reset the cells value as an empty cell
spreadsheetPanel1.SetValue(col, row, "");
//showing the user the problem
MessageBox.Show("Circular Exception");
}
//if a formula format exception is thrown
catch (SpreadsheetUtilities.FormulaFormatException)
{
int col;
int row;
spreadsheetPanel1.GetSelection(out col, out row);
//reset the cells value as an empty cell
spreadsheetPanel1.SetValue(col, row, "");
//showing the user the problem
MessageBox.Show("Invalid Formula!!! Please Enter a valid Formula.");
}
}
//return the result of the evaluated cell
return(result);
}
