Context

A context holds a cached client, the schema service, the status table, the site it reads from and the preferences the formatters need. An app builds one and passes it to every widget, so two widgets asking for the same type’s fields cost one request.

const context = createSgContext({
  client,
  siteUrl: 'https://example.shotgunstudio.com',
  hoursPerDay: 8,
  locale: 'en-GB',
  timeZone: 'Europe/Paris',
  frameRate: 23.976,
});

Options

option	type	default	meaning
client	SgClient	required	The client every read goes through.
ttlMs	number	30000	How long a row read stays fresh.
siteUrl	string	—	The web app the data comes from, so a widget can link a row to its page.
hoursPerDay	number	—	The site’s working day. Durations then render in days.
locale	string	the runtime’s	Used for dates, numbers and currency.
timeZone	string	the runtime’s	IANA zone a date_time is shown in.
frameRate	number	—	Frames a second. A timecode then renders as HH:MM:SS:FF.

What it carries

member	meaning
client	The cached client. Widgets read rows through this one.
schema	Types, fields, dotted paths and status vocabularies.
statuses	The site’s Status table, indexed by code.
siteUrl	The site url without its trailing slash. Empty when the app named none.
preferences	The four preferences above, the ones that were given.
invalidate()	Drops everything cached. Call it after a write.

Rows go stale at ttlMs. Schema and the Status table are site configuration and keep an hour of their own, shared between the two services.

Preferences

The preferences are display decisions the field schema does not carry. GET /preferences names duration_units and hours_per_day, the pair behind a duration (field_types/duration). Nothing on the site names the frame rate behind a timecode: no schema property, no preference and no related field. A _summarize grouping renders one, and solving the rate out of that gives 23.976 on the probed site (field_types/timecode), so the app passes it in.

preferencesOf returns the subset the formatters take, ready to spread.

fieldText(value, dataType, { ...preferencesOf(context), displayValues });

From a client alone

A widget handed a client and no context builds one with contextFromClient. The same client always returns the same context, so widgets that share a client share its caches.

const context = contextFromClient(client);

The options are read on the first call for a client. A later call returns the context that one built.