Calc dueDate gets: No implementation found for 'array - null'

[mr_anh_ngoc]

Hello,
when I try to subtract the due from today i get the error (in topic)

Things I have tried

I have projects like:

file: _P_1

---
projekt: _P_1
objekttype: Projekt
---

file: _P_2

---
projekt: _P_2
objekttype: Projekt

---

and action files:

file: _Aktion1__Pr_2

---
projekt: _P_2
objekttype: Aktion
due-date: 2022-11-12
state: 📅 geplant
---
projekt: [[_P_2]]

file: _Aktion2__Pr_1

---
projekt: _P_1
objekttype: Aktion
due-date: 2022-12-26
state: 📅 geplant
---
projekt: [[_P_1]]

What I’m trying to do

I simply want to calc the remaining days between due-date and today…
via:

TABLE  rows.file.link,
rows.file.frontmatter.due-date - date(today).days AS remain
where contains(state, "geplant") 
group by link(projekt)

but error occurs:

Dataview: Every row during final data extraction failed with an error; first 4:

            - No implementation found for 'array - null'
- No implementation found for 'array - null'
- No implementation found for 'array - null'

is there a possibility to get this via dataview or have I to solve this with dataviewJS… or is this not possibile?

would be nice if someone could explain me.
Thanks.

[mnvwvnm]

I don’t understand well the reason for the group by link(projekt) (projekt in the frontmatter or in the content? in content projekt: [[_P_2]] isn’t a valid format for dataview inline field)… but that isn’t the main question.
To answer directly, try:

TABLE
	rows.file.link,
	map(rows, (r) => (r.due-date - date(today)).days + " days") AS remain
where contains(state, "geplant") 
group by link(projekt)

[mr_anh_ngoc]

Thank you for your reply.

endless search and try of mine has an end…
It works fine.

…I don’t understand well the reason for the group by link(projekt)...

well, if I dont set the group by I’ll get:

anyway… your Code works!

there is only one thing…
How can I query the days, let’s say:

if days remaining <4 then
"🛑 " + map(rows, (r) => (r.due-date - date(today)).days)
else
" " or something
it were too simple, if it works straight ahead
so when I do this:

TABLE
	rows.file.link,
	choice(
		map(rows, (r) => (r.due-date - date(today)).days) < 4,
		"🛑 " + map(rows, (r) => (r.due-date - date(today)).days),
		"⚫ " + map(rows, (r) => (r.due-date - date(today)).days)
		)
where contains(state, "geplant") 
group by link(projekt)

he will spit this out:

maybe there is a simple solution to this?

regards

[mnvwvnm]

About the group by command, my observation is related with the target projekt: it works, but I just don’t understand if intentional - it works because the projekt field in frontmatter, not the projekt: [[_P_1]] in the content.

About your last question, I give you two queries to test (both works, but one is more “clean”):

1 - following the previous query:

TABLE
	rows.file.link AS Project,
	map(rows, (r) => (r.due-date - date(today)).days + " days") AS "Remaining days",
	map(rows, (r) => choice((r.due-date - date(today)).days < 4, "🛑 " + (r.due-date - date(today)).days, "⚫ " + (r.due-date - date(today)).days))  AS Priority
WHERE contains(state, "geplant")
GROUP BY link(projekt)

2 - using flatten to “build” a kind of variable:

TABLE
	rows.file.link AS Project,
	rows.left AS  AS "Remaining days",
	map(rows, (r) => choice(r.left < 4, "🛑 " + r.left, "⚫ " + r.left)) AS Priority
WHERE contains(state, "geplant")
FLATTEN (due-date - date(today)).days AS left
GROUP BY link(projekt)

[mr_anh_ngoc]

wow… thanks.
It was a bit more complicated than that… at least for me

version 2:

well, so much to learn for me.
I hope I can give something back someday.
thanks one more.

have a good night, You have earned it

[mr_anh_ngoc]

Hello,
its me once again.
is there a chance to get a value from the project-file’s YAML-frontmatter into the view from above?
let’s say there is a entry in the project-file P_1:

---
symbol: 🔑
---

how do I get that thing right before the P_1 /P_2 project column?
That it loks like:

which syntax I have to use?
dataview would have to look for the value in “1” in that 1:n relation, as if I see this right…

[mnvwvnm]

two examples:

1 - symbols as autonomous column before the project column:

TABLE WITHOUT ID
	key.symbol AS "",
	key AS Projekt,
	rows.file.link AS Aktion,
	rows.left AS "Remaining days",
	map(rows, (r) => choice(r.left < 4, "🛑 " + r.left, "⚫ " + r.left)) AS Priority
WHERE contains(state, "geplant")
FLATTEN (due-date - date(today)).days AS left
GROUP BY link(projekt)

2 - joining symbol and Project link

TABLE WITHOUT ID
	default(key.symbol, "🪴") +  " " + key AS Projekt,
	rows.file.link AS Aktion,
	rows.left AS "Remaining days",
	map(rows, (r) => choice(r.left < 4, "🛑 " + r.left, "⚫ " + r.left)) AS Priority
WHERE contains(state, "geplant")
FLATTEN (due-date - date(today)).days AS left
GROUP BY link(projekt)

If you always have a symbol in each project, then you can replace default(key.symbol, "🪴") by only key.symbol. I just add this “” to cases where there’s no symbol value and it will be replaced by this emoji (because “appearance” issues: if no symbol value the project link justify to the left of the line)