VIEW013: property-persistence

Bound custom property persistence differs from the project convention

Code	VIEW013
Name	property-persistence
Category	View structure (VIEW)
Default severity	warning
Enabled by default	no
Fix available	sometimes
Fix safety	safe or unsafe, depending on the finding (see below)
ign-lint equivalent	PropertyPersistenceRule

What it does

Checks persistent on the propConfig entries of bound custom properties (custom.* entries with a binding, view level and components) against expected-persistent. A missing persistent means persistent. Nothing is checked until expected-persistent is set.

• expected-persistent = false: reports bound properties that are persistent. The Designer then writes every binding result into view.json, which bloats the file and produces noisy diffs.
• expected-persistent = true: reports bound properties that are not persistent, and persistent ones without a stored default value.

Why is this bad?

A bound, persistent property stores the Designer's last binding result in the resource. Query results and tag values end up in version control and change on every save.

Example

With expected-persistent = false:

{"custom": {"rows": [1, 2, 3]},
 "propConfig": {"custom.rows": {"binding": {"type": "query", "config": {"queryPath": "Rows"}}}}}

Use instead:

{"custom": {},
 "propConfig": {"custom.rows": {"binding": {"type": "query", "config": {"queryPath": "Rows"}}, "persistent": false}}}

Options

• expected-persistent (unset by default): true or false; unset disables the rule.
• exempt-binding-types (default ["tag"]): binding types that are not checked: expr, expr-struct, property, query, tag (every tag mode), tag.direct, tag.indirect, tag.expression, and the other registered types (tag-history, http). Default ["tag"]; [] checks everything.

Fix

For expected-persistent = false: sets persistent: false and removes the stored value (when its path has no array index). Safe when there is no stored value (the property starts out absent either way). Unsafe when there is one: until the binding delivers its first value (query bindings are asynchronous), startup scripts, change scripts and expressions see the stored value before the fix and no value after it.

Like every fix, it is unsafe while code in the workspace may read the files a fix edits (any file access, read, write, rename or delete, whose path is not a literal outside the workspace, or code that is not vetted); the project setting [fix] assume-scripts-do-not-read-workspace-files = true declares that no script does (see docs/internal/fix-safety.md, "File reads").

ign-lint

Equivalent of PropertyPersistenceRule (expected_persistent, exempt_binding_types), with the same messages in iglint ign-lint.

Option reference

Set in [rules.VIEW013] of iglint.toml (or [tool.iglint.rules.VIEW013] in pyproject.toml).

Option	Type	Default	Description
expected-persistent	boolean	none	Whether bound custom properties must be persistent.
exempt-binding-types	array of strings	["tag"]	Binding types that are not checked.

ign-lint kwargs in a rule_config.json: expected_persistent -> expected-persistent, exempt_binding_types -> exempt-binding-types.

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Generated from the rule metadata by iglint generate-docs; iglint rule VIEW013 prints the same page in the terminal. Source: docs/rules/VIEW013.md.