Skip to main content

Schemas

A schema is the shape of one kind of record. A customer, a ticket, an asset. Your schemas are your app's data, and every widget that shows anything is showing a schema.

Registers and schemas​

A register is the container. A schema is one record type inside it. An app usually has one register and several schemas.

Both are OpenRegister objects, which is why there is no database migration step. You add a field and the store accepts it.

Defining fields​

The schema designer takes it field by field: a name, a type, and whether it is required. Types cover text, numbers, dates, enumerations and relations to other schemas.

A relation is what lets a detail page show related records, and what lets a widget on one schema count rows in another.

Logic belongs on the schema​

This is the part that saves the most code. State machines, aggregations, calculations and notifications are declared as schema metadata, not written as service classes. The rule lives with the data it governs, so it applies however the data is written.

For logic that outgrows metadata, use a flow. See Flows.

Calculated fields​

A calculated field gets its value from the record's other fields, such as a total that is the quantity times the unit price. Open a schema in the schema designer and go to Calculations:

  1. Type the name of the field and choose "Add calculated field". A name the schema does not have yet becomes a new field.
  2. Choose the type of the result: text, whole number, number, yes or no, or a date.
  3. Build the expression. Each part is a field of the record, a value you type, or an operator such as multiply or add. An operator's parts are built the same way, so you can nest them.
  4. Fill in sample values and choose "Try". The result shows below, and nothing is saved.
  5. Save the schema. OpenRegister checks the calculation; when it refuses, the reason shows next to the field and your edit stays in the designer.

OpenRegister stores the calculated value with each record, so a list can sort and filter on it. A calculation written in the register file itself is listed too, but it can only be changed in that file.

Access​

Per-record access is enforced by OpenRegister, not by your app. A user who may not read a record does not receive it, whichever page asked. That holds for the API as well as the UI, so a page cannot leak what a permission denied.

Changing a schema later​

Add a field and existing records simply lack it. Widgets reading that field show nothing for the older rows rather than failing. Plan for that when you make a new field required.

Next: make something happen when the data changes. See Flows.