Types of changes

Changes visible to users:

• New feature (prefix: feat - non-breaking change which adds functionality)
  • Issue/discussion:
  • Expose query.file.property similarly to task.file.property #3083
  • Support for using YAML front Matter Values as Variables in Queries [via placeholder values, without the need for 'filter by function'] #3154

Internal changes:

• Tests (prefix: test - additions and improvements to unit tests and the smoke tests)

Description

Add access to query.file.property() and query.file.hasProperty()

Example with placeholders

---
task_instruction: group by filename
---

```tasks
{{query.file.property('task_instruction')}}
```

Note: Only placeholders only work with single-line properties in this first version.

Example with custom filters

Note the example error-checking for if the property is not set.

---
root_dirs_to_search:
  - Formats/
  - Filters/
---

```tasks
filter by function \
    if (!query.file.hasProperty('root_dirs_to_search')) { \
        throw Error('Please set the "root_dirs_to_search" list property, with each value ending in a backslash...'); \
    } \
    const roots = query.file.property('root_dirs_to_search'); \
    return roots.includes(task.file.root);
```

Definite Limitations

• Documentation will be provided later, once I have more experience using this in my own vault.
• Only single-line properties work. Multiple-line properties give an error message 'do not understand query'.
• It does not listen out for edits the properties, so if a property is edited, the user needs to close and re-open the file.

Possible limitation

• If the query file was created in the last second or two before the query is run, any CachedMetadata may not yet be available - in which case, the properties could not be read.

Motivation and Context

This is the majority of the implementation needed for:

• Expose query.file.property similarly to task.file.property #3083
• Support for using YAML front Matter Values as Variables in Queries [via placeholder values, without the need for 'filter by function'] #3154

How has this been tested?

• Automated tests
• Exploratory testing

Screenshots (if appropriate)

Checklist

• My code follows the code style of this project and passes yarn run lint.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• My change has adequate Unit Test coverage.

Terms

• My contribution follows this project's contributing guide
• I agree to follow this project's Code of Conduct