# Edit Resource Properties

Resource schemas provide typed property groups and values for inspection and local editing. Editing a schema does not persist changes by itself; use a resource builder to submit the edited model.


# Read values

``` python
plate = namespace.query_maker().resources(load="eager").first()
plate.build_property_model()

rows = plate.properties.dimensions.rows.value
unit = plate.properties.dimensions.rows.unit
```

Attributes support dot access and bracket access. Brackets accept either the normalized slug or the original attribute name, and `.get(name)` returns a missing attribute as `None`.

``` python
group = plate.properties["dimensions"]
rows = group["rows"].value
rows = group.get("rows").value
```


# Modify and persist values

``` python
with namespace.build_resource(resource_id=plate.id) as builder:
    model = builder.get_model()
    model.properties.dimensions.rows = 16
    model.properties.dimensions.rows.unit = "count"
    builder.set_model(model)
```

The builder validates values against the template and persists the aggregate on successful context-manager exit. An exception rolls the change back.


# Units and metadata

Setting an attribute value preserves its existing unit. Set the unit explicitly when the update changes its meaning. Template metadata can constrain numeric ranges or enumerate allowed values; invalid values fail validation before the mutation is committed.