MetaVox Flow Integration

MetaVox integrates with Nextcloud's Flow (Workflow Engine) to enable metadata-based automation and access control.

Overview

With Flow integration, you can create rules like: - Block access to documents marked as confidential - Tag files automatically based on their metadata

The MetaVox check is only available in the admin Flow settings. Personal Flow rules (Settings > Personal > Flow) cannot use it: a personal rule could test values of files the user only reaches through a share. The server refuses a rule with the MetaVox check from anyone who is not a Nextcloud administrator (delegated Flow admins included), also when it is posted to the Flow API directly.

Prerequisites

1. MetaVox installed and configured
2. For access control: Install Files Access Control app from the Nextcloud App Store

Setting Up Flow Rules

Creating a Rule

1. Go to Settings > Administration > Flow
2. Click Add new flow
3. Select a trigger (e.g., "File accessed", "File created")
4. Under Conditions, click Add condition
5. Select "MetaVox metadata" from the dropdown
6. Configure your condition:
7. Metadata field: Select the metadata field to check
8. Operator: Choose from the operators for that field type
9. Value to check: Enter the value to compare against (hidden for is empty, is not empty, is checked and is not checked)
10. Team folder (optional): Auto-detect (the default) or one specific team folder

Which Files a Rule Applies To

• Files in a team folder only. The check looks up the team folder the file is in. Files outside a team folder never match, and neither do files in a team folder's trash or versions.
• Files, not folders. The check never matches a folder.
• Team folder (optional): with Auto-detect, the rule applies in every team folder. Pick a team folder and the rule only applies to files in that one; files in other team folders never match.
• The file's own values. The check compares the value stored on the file. The field list also offers Team folder metadata fields, but their value belongs to the team folder, not to the file, so the check sees them as empty.

Available Operators

The operator list depends on the field type. It is the list of the highlight rules in the grid, without the two that count days from today, and a rule reads the same in both:

Field type	Operators
Text, Long Text	equals, is not, contains, does not contain, is empty, is not empty
Number	equals, is not, greater than, less than, greater or equal, less or equal, is empty, is not empty
Date	is before, is after, equals, is empty, is not empty
Dropdown	equals, is not, is one of, is empty, is not empty
Multi-select	is one of, contains all, is empty, is not empty
Checkbox	is checked, is not checked
URL	equals, is not, contains, does not contain, is empty, is not empty
User	equals, is not, is empty, is not empty
File Link	is empty, is not empty

How they compare:

Operator	Description
equals / is not	Exact match (or not), not case-sensitive
contains / does not contain	Value contains the text (or not), not case-sensitive
is empty / is not empty	Field has no value / has a value
is before / is after	Date is before / after the given value; both are compared as points in time
greater than, less than, greater or equal, less or equal	Numeric comparison; a value that is not a number never matches
is one of	Dropdown: the value is one of the selected options. Multi-select: the file has at least one of them
contains all	Multi-select: the file has every selected option
is checked / is not checked	Checkbox; one that was never set counts as not checked

A multi-select is compared per option, not as text: "is one of IT" does not match a file that has only "IT-beheer".

For date fields the value picker switches automatically: date-only fields use a date input, fields with Include time component enabled use a datetime-local input.

Rules made earlier keep working and keep their operator in the form: a checkbox rule with equals "Yes (checked)" or "No (unchecked)", or a multi-select rule with contains, which is shown as is one of now. Earlier, a multi-select rule with contains or contains all did not match files with more than one option; it does now.

The server also accepts the operators matches and !matches (regular expression) for rules created through the Flow API.

Field-Specific Input

The value input adapts to the field type: - Dropdown fields: The configured options; is one of allows several - Multi-select fields: The configured options, several at once - Checkbox fields: no value; the operator says it - Date fields: Date picker (with time when the field includes time) - Number fields: Numeric input - Other fields: Free text input

Example Use Cases

Block Access to Confidential Files

1. Create a Flow rule with trigger "File accessed"
2. Add condition: MetaVox metadata > classification equals confidential
3. Add action: Block access

Result: Users cannot access files marked as confidential unless the condition is changed.

Block Access to Unreviewed Documents

1. Create a Flow rule with trigger "File accessed"
2. Add condition: MetaVox metadata > review_status is one of draft, in review
3. Add action: Block access

Result: Documents that haven't been reviewed cannot be opened or downloaded. Files without a review status are not blocked by this rule; add a second rule with is empty if they should be.

Auto-Tag Based on Metadata

1. Create a Flow rule with trigger "File created"
2. Add condition: MetaVox metadata > department equals Legal
3. Add action: Add tag "legal-team"

Result: Files created in the Legal department are automatically tagged.

Tips

• Field grouping: The field list has two groups: "File metadata fields" and "Team folder metadata fields"
• Testing: Test rules with non-critical files first
• Logging: Check Nextcloud logs if rules don't trigger as expected; a failed check is logged as "MetaVox Flow check failed"

Admin vs Personal Flow

Action	Where to configure	Scope	MetaVox check
Block access to a file	Settings > Administration > Flow	Applies to all users	Available
Send notification	Settings > Personal > Flow	Applies to you only	Not available

Notification flows are personal in Nextcloud, so they cannot use MetaVox metadata as a condition.

Limitations

• Flow rules evaluate when triggers fire (file access, creation, etc.)
• Metadata changes alone may not trigger rules unless combined with file events
• Complex conditions may require multiple rules

See Also

• Compliance Templates - Pre-built metadata schemas with Flow examples
• Permissions - Access control basics
• Architecture Overview - How Flow integration works technically