BIND004: polling-interval

Expression polls faster than the minimum interval

Code	BIND004
Name	polling-interval
Category	Bindings and expressions (BIND)
Default severity	warning
Enabled by default	yes
Fix available	no
ign-lint equivalent	PollingIntervalRule

What it does

Finds calls of polling expression functions in bindings and reports those that poll faster than minimum-interval milliseconds:

• now(n) with a literal 0 < n < minimum-interval;
• now() without an argument, which polls every 1000 ms;
• runScript(script, n, ...) with a literal poll rate 0 < n < minimum-interval.

A rate of 0 (or less) means "do not poll" and is fine. A rate that is not a literal (now({view.custom.rate})) cannot be checked and is only reported with strict.

Calls are found by parsing the expression, so snow(5) and 'now()' inside a string literal are not calls of now. Every expression of a binding is checked: expression and expression-structure bindings, tag bindings in expression mode, query binding parameters, expression transforms and map transform expressions, in views and session properties.

Why is this bad?

Every polling expression re-evaluates on its own timer in the gateway, for every open session. Fast polling of many bindings is a common cause of gateway load.

Example

dateFormat(now(), "HH:mm:ss")

Use instead:

dateFormat(now(10000), "HH:mm:ss")

Options

• minimum-interval (default 10000): the smallest allowed poll rate in milliseconds.

ign-lint

Equivalent of PollingIntervalRule (kwarg minimum_interval), with the same message in iglint ign-lint. Differences: ign-lint matches text, so it also reports snow(5), now() inside string literals and now(-1), and ignores a dynamic now({...}) when the same expression also has a literal now(n); it reads indirect tag binding references (property paths, not expressions) as if they could poll. It reports one finding per string, iglint one per expression at the first offending call.

Option reference

Set in [rules.BIND004] of iglint.toml (or [tool.iglint.rules.BIND004] in pyproject.toml).

Option	Type	Default	Description
minimum-interval	integer	10000	Smallest allowed poll rate in milliseconds.

ign-lint kwargs in a rule_config.json: minimum_interval -> minimum-interval.

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Generated from the rule metadata by iglint generate-docs; iglint rule BIND004 prints the same page in the terminal. Source: docs/rules/BIND004.md.