| **Navigation:**  [[abc library reference.htm|ABC Library Reference]] > ASCIIFileClass > AsciiFileClass Methods >====== ValidateLine (a virtual to implement a filter) {{c6h0009.jpg|C6H0009.jpg}} ====== | [[setpercentile set file to relative position .htm|{{btn_prev_n.gif|Previous page}}]][[abc library reference.htm|{{btn_home_n.gif|Return to chapter overview}}]][[asciiprintclass.htm|{{btn_next_n.gif|Next page}}]] | | || **ValidateLine( **//line //**), PROTECTED, VIRTUAL** {{blk2blue.jpg|blk2blue.jpg}} | **ValidateLine** | A virtual placeholder method to implement a filter. | | //line// | The offset or position of the line of text to evaluate. | The **ValidateLine **method is a virtual placeholder method to implement a filter. ValidateLine returns one (1) to include the //line //and zero (0) to exclude the //line//. **Implementation:** The ValidateLine method is a placeholder method for derived classes. The ASCIIFileClass calls the ValidateLine method when it initially reads a record. **Return Data Type:     **BYTE **Example:** **MyFileClass.ValidateLine FUNCTION(STRING LineToTest)** ** CODE** ** IF LineToTest[1] = '!'           !check for ! in column 1** **  RETURN False                    !exclude lines with !** ** ELSE** **  RETURN True                     !include all other lines** ** END**