Help with query

[arcegabriel]

I am running into issues with a query. Much appreciate assistance
The frontmatter property "up" is a list of wikilinks
This query is giving me an error. I tried replacing the { by [ and same issue

{ { filter by function task.file.hasProperty('up') } AND { { path includes Notes } OR { path includes Private } } AND  { filter by function task.file.property('up').join(',').includes(query.file.filenameWithoutExtension) } } 

The error message was:

    "TypeError: Cannot read properties of null (reading 'join')"

Possibly not all the notes has the property "up" or has anything on the property "up"
Please and thanks!

[claremacrae]

Please paste in an example frontmatter block that I can use for testing and reply.

Thank you.

[arcegabriel]

Sample

---
created: 2025-07-21
up:
  - "[[APAC Support Program]]"
related: 
aliases: 
tags:
---

Note

1. Sometimes up maybe empty
2. Sometimes up may have more than 1 entry
3. Sometimes up maybe missing altogether

[claremacrae]

Thanks.

Also, just to note that I have edited the original post to put the quoted text in code blocks, for read-ability and copy-ability.

[claremacrae]

Initial comments

There are two problems:

1. Inconsistency types of data in your up property in your vault
2. Complexity of your query, making it harder to debug what what is going on.

Sample data

I created a variety of test notes, with different types of value in the up property.

These are their contents:

==> 3543 - QandA - Help with query - sample 1 - Notes - has single list value.md <==

---
created: 2025-07-21
up:
  - "[[APAC Support Program]]"
related: 
aliases: 
tags:
---

# 3543 - QandA - Help with query - sample 1 - Notes - has single list value

- [ ] 3543 - QandA - Help with query - sample 1 - Notes - has single list value

==> 3543 - QandA - Help with query - sample 2 - Notes - has two values.md <==

---
created: 2025-07-21
up:
  - "[[APAC Support Program]]"
  - "[[Somerset]]"
related:
aliases:
tags:
---

# 3543 - QandA - Help with query - sample 2 - Notes - has two values

- [ ] 3543 - QandA - Help with query - sample 2 - Notes - has two values 

==> 3543 - QandA - Help with query - sample 3 - Notes - has different value.md <==

---
created: 2025-07-21
up:
  - "[[Somerset]]"
related:
aliases:
tags:
---

# 3543 - QandA - Help with query - sample 3 - Notes - has different value

- [ ] 3543 - QandA - Help with query - sample 3 - Notes - has different value

==> 3543 - QandA - Help with query - sample 4 - Notes - has empty value.md <==

---
created: 2025-07-21
up: []
related:
aliases:
tags:
---

# 3543 - QandA - Help with query - sample 4 - Notes - has empty value

- [ ] 3543 - QandA - Help with query - sample 4 - Notes - has empty value

==> 3543 - QandA - Help with query - sample 5 - Notes - has no property.md <==

---
created: 2025-07-21
related:
aliases:
tags:
---

# 3543 - QandA - Help with query - sample 5 - Notes - has no property

- [ ] 3543 - QandA - Help with query - sample 5 - Notes - has no property

==> 3543 - QandA - Help with query - sample 6 - Notes - has string value.md <==

---
created: 2025-07-21
up: "[[APAC Support Program]]"
related:
aliases:
tags:
---

# 3543 - QandA - Help with query - sample 6 - Notes - has string value

- [ ] 3543 - QandA - Help with query - sample 6 - Notes - has string value

Which files cause the search to fail - part 1

Your query executes if I delete files 5 and 6.

So these are the two (or at least, two) scenarios that the query does not handle correctly.

At first sight, it looks like the query should work fine with file 5, because of this:

filter by function task.file.hasProperty('up')

However, by including that in the Boolean combination, it causes all expressions to be evaluation, even if the first one fails.

So I can make the query work with file 5 by changing it to this - that is, adding the check for up to its own line, so that any tasks without that property never get as far as the boolean line.

(Note I used a hard-coded APAC Support Program file name for ease of my own testing)

filter by function task.file.hasProperty('up')
{ { filter by function task.file.hasProperty('up') } AND { { path includes Notes } OR { path includes Private } } AND  { filter by function task.file.property('up').join(',').includes('APAC Support Program') } } 

Which files cause the search to fail - part 2

The other file that causes the search to fail is file 6, which does not have an array value for up, it has a single string value.

You have written your search to call .join() which only exists on arrays, not strings.

So you have 2 choices:

1. Fix your properties to make them consistent
2. Adjust your search logic to make it work for string values as well as arrays. One way of doing that might be to use JSON.stringify(). I have already spent about an hour on this, and do not have time to write that search for you.

Simplifying your filters

I recommend you try to break up your long filter expression line.

Each separate Tasks query line is ANDed together with the others.

So a query:

(A) AND (B) AND (C)

Can be made much more readable, and easy to reason about, like this:

A
B
C

Checking your logic

I recommend add the following line to your query, to check your logic:

explain

[arcegabriel]

Thanks @claremacrae - much appreciate you taking the time
I only have the issue with fail part 1. And it resolved it once I followed your suggestion

The challenge is now that condition applies to the whole query --> filter by function task.file.hasProperty('up')
My final query is more complex and I also wanted to query/filter tasks in other notes in the folder Journal
[ [ path includes Journal ] AND [ filter by function task.description.includes( query.file.filenameWithoutExtension) ] ]
But those notes do not have the property up and it should not be filtered out

With your solution I need to have two separate queries and not a single one
Let me know if any suggestions.

[claremacrae]

It would help if you could please put query text on code blocks, as per my comment above.

[arcegabriel]

thanks done. Obviosuly I am not a programmer 😬

[claremacrae]

Looking at the documentation, I see that I have previously identified two possible approaches:

https://publish.obsidian.md/tasks/Getting+Started/Obsidian+Properties#Use+%60+project%2F...%60+tag+values

There are links in that section to explanations of the language features used - though I appreciate they may need some programming background to understand.

Again, you will need to remove the hard-coded file name from these examples.

Option 1 - works for file 5 but not 6

Change this:

filter by function task.file.property('up').join(',').includes('APAC Support Program')

to this:

filter by function task.file.property('up')?.join(',').includes('APAC Support Program') ?? false

Option 2 - works for 5 and 6, and is less code - less error-prone

Note that the punctuation is critical in these examples - backticks versus other quotes.

filter by function `${task.file.property('up')}`.includes('APAC Support Program')

You can see the effect of expression by using this simpler search:

group by function `Group: "${task.file.property('up')}"`
limit 100
limit groups 1

[arcegabriel]

Brilliant @claremacrae much appreciated ! Going for option 2 - both options work 🙏
Thanks for being so generous to look into my question 😊