Custom column from tags

[jelzin]

I try to create a custom column that contains a date value from the tags column. The format of that tag is 'year-month-day' (where the month and day will be padded with 0 to length 2) eg. 2021-03-15.

I tried this function to get it but it's not working and i can't figure out why (could be the regex or i'm using the wrong function here or all those ' are canceling themselfs out somehow?):

{:'list_re(field('tags'), ',' ,'\d{4}-\d{2}-\d{2}')'}

Would be nice if someone could help me out with this one.

The next problem will be to create a hierarchy from that date field:
Year.Month.Day

I know i could easily create an custom column with a hierarchy but i try to use the default columns and create automated custom columns from those.

Thanks,

Johan

[chaley]

Use

program: list_re(field('tags'), ',', '\d{4}-\d{2}-\d{1}', '')

The problem: the { and } characters can't reliably be used in Template Program Mode because the template parser thinks they are full templates.

[jelzin]

Thanks chaley, you made my day!

I took it a step forward to create a hierarchy date format with this code:

program:
 list_split(list_re(field('tags'), ',', '\d{4}-\d{2}-\d{2}', '') , '-' , 'vars');
 strcat(vars_0,'.',vars_1,'.',vars_2)

This will change the extracted date (eg. 2021-03-15) to 2021.03.15

It may not be the nicest code but it works!

[chaley]

Originally Posted by jelzin

Thanks chaley, you made my day!

I took it a step forward to create a hierarchy date format with this code:

program:
 list_split(list_re(field('tags'), ',', '\d{4}-\d{2}-\d{2}', '') , '-' , 'vars');
 strcat(vars_0,'.',vars_1,'.',vars_2)

This will change the extracted date (eg. 2021-03-15) to 2021.03.15

It may not be the nicest code but it works!

That is a nice use of list_split(). It makes it really easy to do post processing on the values. For example, you could easily add a hierarchy level for the decade or century.

Another quite similar way to do it would be to use the replacement pattern in list_re:

program: list_re(field('tags'), ',', '(\d{4})-(\d{2})-(\d{2})', '\1.\2.\3')

This implementation isn't better in any cosmic sense, but if someone is very familiar with regular expressions it might be easier to understand.

[jelzin]

Another quite similar way to do it would be to use the replacement pattern in list_re:

program: list_re(field('tags'), ',', '(\d{4})-(\d{2})-(\d{2})', '\1.\2.\3')

This implementation isn't better in any cosmic sense, but if someone is very familiar with regular expressions it might be easier to understand.

This is a nice one-liner!
I'm not quite familiar with regular expressions but this one i do understand and i like it!