Saving a CSV with the following format in iPhone application - iphone

Question

In my application I have a simple logbook where the user can save simple posts about an event. The format is like this:
Date, duration(seconds), distance(km), a comment AND categories with a variable number between 0 - 4 AND circumstances/conditions with a variable number between 0 - 4
An example would be:
Header of CSV file
Date,Duration,Distance,Comment
Then multiple rows like this
07.02.11,7800,300,"A comment"
07.02.11,7800,300,"A comment"
07.02.11,7800,300,"A comment"
But how can I add the categories and conditions to this format and how would I know where in the categories/conditions end in the CSV if I at a later point in the application want to import the file again?
(I do not need help with how to save etc this to file, already done that, but I could need guidiance on how to format it, thank you)
(This seems pretty odd)
Header of CSV file
Date,Duration,Distance,Comment, Category, Category, Category, Category, Condition, Condition, Condition, Condition
Then multiple rows like this
07.02.11,7800,300,"A comment", "Categoryname", "Categoryname", "Categoryname","Categoryname", "Condtion", "Condition", "Condtion", "Condition"
(Would this be better)
Header of CSV file
Date,Duration,Distance,Comment, Category, Condition
Then multiple rows like this
07.02.11,7800,300,"A comment", "Multiple category names separted by -", "Multiple condition names separted by -"

Answer 1

I think you last proposal of separating conditions or categories using a special separator symbol (the hyphen in your example) is the right one.
By the way I would suggest two extra things:
use a less common separator, that is something you can forbid the user to use without limiting user choice; probably the hyphen is a character you don't want to forbid, use a different sequence such as three pipes: ||| which is not common.
if possible (but be careful in this case about final destination of the CSV file) you can avoid using the standard "comma separator". The reason for this is that if comma is used inside the fields content, then this content must be separated by double quotes. This is some time problematic if you need to do some custom parsing by other software. Normally when I know that my CSV will not be used as source import from other software (e.g. Numbers or Excel) I prefer to use a different separator, e.g. a sequence of 2 hash (##) or something more "strange". Note that in this case you are no more strict-CSV compliant! but there is some software, like OpenOffice, which is more flexible with this special formats.

Answer 2

The second solution you are proposing will work but practically defeats the idea of using a standard format, since you will need to do the parsing of categories and conditions on your own instead of using a standard CSV parser. Writing your own parser is never good.
I would personally do this differently: not trying to put everything in a single file and have two files, one for events (each event has a unique id) and the other for categories/conditions (each category condition is associated to an event through the event's id, multiple categories/events for a given event would appear on multiple lines associated sharing the same event id). Both files would be standard CSV files.
As an alternative, if you are not tied to CSV for any reason, you might think of using JSON, which allows for a richer set of data types, including arrays, and offers plenty of code that you can reuse. This will not require much change to your code.
Another option, more "canonical" (IMO) but also more expensive in terms of code rewrite, would be using sqlite3.
If I had to choose, I would go for JSON, but I don't know if this is ok for you.