Crash Course Delphi 17 [beta]:
CSV Files - part 4


Modify records: Edit


Editing records: modifying the contents of your database.

Improved versions for ParseRecord and SaveRecord, that follow all of the CSV format rules.


Analysis

The easiest way to change a record, is by editing one or more fields in the stringgrid of the database. But initially, when a stringgrid is dropped on a form, it is in "read only" mode. We changed this by modifying a few properties of the stringgrid (see above).

These changes will result in a few unexpected side effects, but we'll arrange that in our next lesson ;)

Earlier, we also promised to develop a better ParseRecord procedure, that fully follows all of the CSV format rules. We also present an improved AddRecToList procedure to go with it.

The new ParseRecord procedure has a better way of finding field separators, using the helper function PosFirstSep. For the rest, it's pretty much the same as the routine in our previous lesson.

The PosFirstSep helper function returns the position of the first separator comma in a given record string. That's not simply the first comma, because we also can have commas and double quotes inside a field value, as in this example:

"begin, ","""loops"" in Pascal"

The improved AddRecToList procedure is almost like the routine presented in lesson 16, except that now we also encode double quotes that are contained in a field values.



 Lesson 16    Lesson 18