viewModelFactory

Creates a ViewModel class with the specified fields.

const fields = {
    userId: new IntegerField({ label: 'User ID' })
    firstName: new CharField({ label: 'First Name' }),
    // label is optional; will be generated as 'Last name'
    lastName: new CharField(),
};
// Options are all optional and can be omitted entirely
const options = {
    // Only one of pkFieldName or getImplicitPkField can be defined.
    // If neither are provided a default field called 'id' will be created.
    pkFieldName: 'userId',
    // Multiple names can be specified for compound keys
    pkFieldName: ['organisationId', 'departmentId']
    // You can also specify a function to create the primary key
    getImplicitPkField(model, fields) {
         if ('EntityId' in fields) {
             return ['EntityId', fields.EntityId];
         }
         // Generate a name base on model, eg. `userId`
         const name = model.name[0].toLowerCase() + model.name.slice(1);
         return [`${name}Id`, new NumberField()];
     },
     // Optionally can specify a baseClass for this model. When using `augment`
     // this is automatically set to the class being augmented.
     baseClass: BaseViewModel,
};
class User extends viewModelFactory(fields, options) {
    // Optional; default cache is usually sufficient
    static cache = new MyCustomCache();
    // Used to describe a single user
    static label = 'User';
    // User to describe an indeterminate number of users
    static labelPlural = 'Users';
}

The cache instance for this ViewModel. A default instance of ViewModelCache is created when first accessed or you can explicitly assign a cache:

class User extends viewModelFactory(fields) {
    static cache = new MyCustomCache(User);
}

Shortcut to get the names of all fields excluding primary keys.

If you want all fields including primary key do:

model.fieldNames.concat(model.pkFieldNames);

The bound fields for this ViewModel. These will match the fields passed in to ViewModel with the following differences:

• If a primary key is created for you this will exist here
• All fields are bound to the created class. This means you can access the ViewModel class from the field on the model property, eg. User.fields.email.model === User will be true.
• All fields have the name property set to match the key in fields
• All fields have label filled out if not explicitly set (eg. if name was emailAddress label will be created as Email Address)

See also getField for getting a nested field using array notation.

The singular label for this ViewModel. This should be set by extending the created class.

class User extends viewModelFactory(fields) {
    static label = 'User';
}

The label used to describe an indeterminate number of this ViewModel. This should be set by extending the created class.

class User extends viewModelFactory(fields) {
    static labelPlural = 'Users';
}

Name of the primary key field for this this ViewModel (or fields for compound keys)

If options.pkFieldName is not specified a field will be created from options.getImplicitPk if provided otherwise a default field with name 'id' will be created.

Shortcut to get pkFieldName as an array always, even for non-compound keys

List of field names with data available on this instance.

The assigned data for this record. You usually don't need to access this directly; values for a field can be retrieved from the record directly using the field name

Access record bound fields. A record bound field is a normal field with it's value property set to the corresponding value for that field on the record. This is useful as a shortcut to get both the field and it's value.

class User extends viewModelFactory({ username: CharField() }) {}
const admin = new User({ id: 1, username: 'admin' });
// true
admin._f.username instanceof CharField();
admin._f.username.value === 'admin'

Returns the primary key value(s) for this instance. This is to conform to the Identifiable interface.

Get the actual ViewModel class for this instance