CnCronField

A schedule builder that writes a standard five-field cron expression.

<CnCronField v-model="config.cron" :label="t('myapp', 'Runs')" />

Cron is a precise notation and an unreadable one. 0 9 * * 1 is exact, and nobody reads it at a glance — so a bare text box asks every author to know a syntax in order to say "every Monday morning", and gives no feedback at all until the schedule fails to fire at a time nobody is watching.

The three views are one value

The named schedule, the part pickers and the expression are the same value seen three ways:

• picking Every week rewrites the expression
• typing an expression re-selects the schedule it matches
• an expression matching none of them selects Custom…, which is not a failure state — it is every schedule the presets cannot name

The expression stays visible and editable in all modes. A builder that hides the value it produces cannot express what cron can, and cannot be checked by someone who already knows what they want.

Props

Prop	Type	Default	Description
modelValue	String	''	The cron expression, as five space-separated fields.
label	String	''	Label for the schedule picker.
disabled	Boolean	false	Whether every control is disabled.

Events

Event	Payload	When
update:modelValue	string	The expression changed. Always five space-separated fields, never a @shortcut.

What it will not produce

@daily and its siblings. Which shortcuts a scheduler resolves varies by implementation, and a schedule that validates and never fires is worse than one that is refused. Output is always five fields — the form every cron implementation agrees on.

A day of the month above 28. A schedule on the 31st silently skips the months that do not have one, which the author cannot see until February. Typing 0 9 31 * * by hand still works and still validates; the builder simply will not steer anyone into it.

Invalid input is emitted, not swallowed

Keystrokes are never rejected. Almost every prefix of a valid expression is itself invalid, so a field that refused them would be impossible to type in. The error text says what is wrong and the caller decides whether to save — pair it with OpenRegister's format: "cron", which refuses the write.

The summary says nothing rather than something wrong

describeCron() names only the shapes the builder produces. Anything else returns an empty string instead of an approximation: a summary that confidently describes a different schedule than the one that will run is worse than no summary, because it is believed.

So 0 9 * * 1 reads as "Every Monday at 09:00", and 0 9 * * 1-5 — a perfectly valid expression — reads as nothing at all.

Related

• parseCron / isValidCron / describeCron in src/utils/cron.js
• OpenRegister's format: "cron" validates the same grammar server-side