using tryEvaluate with dv.page() expression

[jmutchek]

Is it possible to use dv.page() within a tryEvaluate() expression? I'd like to be able to store an expression in the front matter of a note and use it to evaluate conditions in a different block of code.

Example Notes

Note 1: Reference

---
MyValue: 10
MyExpression: dv.page('Reference').MyValue > 0
---

Note 2: Test

1. Reference.MyValue = `$= dv.page('Reference').MyValue`
2. Reference.MyExpression = `$= dv.page('Reference').MyExpression`
3. Simple tryEvaluate = `$= dv.page('Reference').MyValue > 0`
4. Direct tryEvaluate = `$= dv.tryEvaluate("dv.page('Reference').MyValue > 0")`
5. Expression via tryEvaluate = `$= dv.tryEvaluate(dv.page('Reference').MyExpression)`

Results

When I put Note 2 into reading mode I get the following results and an error on the final inline expression

Reference.MyValue = 10
Reference.MyExpression = dv.page('Reference').MyValue > 0
Simple tryEvaluate = true
Direct tryEvaluate = $= dv.tryEvaluate("dv.page('Reference').MyValue > 0")
Expression via tryEvaluate = $= dv.tryEvaluate(dv.page('Reference').MyExpression)

> Dataview (for inline JS query 'dv.tryEvaluate("dv.page('Reference').MyValue > 0")'): Error: Failed to parse expression "dv.page('Reference').MyValue > 0"

> Dataview (for inline JS query 'dv.tryEvaluate(dv.page('Reference').MyExpression)'): Error: Failed to parse expression "dv.page('Reference').MyValue > 0"

Question

The string that the tryEvaluate parser chokes on appears to be identical to the one used in line 3 in a straight inline JS expression. This might mean that dv is not available within tryEvaluate, in which case the error message could be more specific. I hope that there is a way to make dv available from within the expression when using tryEvaluate just as it is with inline javascript.

Any pointers? Thanks in advance!

[blacksmithgu]

Evaluate uses DataviewQL and not javascript - I'll need to add an evaluateJs method.

In the meanwhile, you can access fields on the current file via this.field, and links to other files via [[Page]].field.

[jmutchek]

That explains it. I somehow added a 'js' in my head when I read 'dataview expression' in the docs. :) In the meantime, your response prompted me to try a straight javascript eval(dv.page('Reference').MyExpression) which seems to work as I would expect in my first tests. I assume that there may be other use cases where a Dataview evaluateJs method would be a better long-term solution. Thanks!