Table of Contents

Convention: Property Required Name Checks

On newer APIs we implement a policy that properties are required by default (but you can override this). This applies to newer base classes such as

This means that by default, retrieving any property such as something.String("FirstName") will only work, if the underlying Entity has the property FirstName. Otherwise it will throw an error.

Why?

This should help you find errors earlier, and make your code more stable. Previously when using dynamic objects, it was easy to make a typo and not notice it, or to be using the wrong object (such as having and underlying BlogPost object instead of a Category object).

How to Override

You can override this at object/wrapper creation, or when retrieving the value.

When creating the object, you can override the default behavior by setting the required parameter on value getters, or propsRequired on item-conversions. Example:

var lax = AsItem(someEntity, propsRequired: false);
var willBeNull = lax.String("DoesNotExist");

When accessing a property, you can override it by using the required parameter. Example:

var willBeNull = MyItem.String("DoesNotExist", required: false);
Tip

The required parameter is a nullable boolean. This is to ensure that it's clear if you set it or not, in which case the default will be used.

Behavior when providing a fallback value

Most methods which have a required also have a fallback parameter. This is a value which will be returned if the property is empty or is not populated.

So there is a slightly different behavior.

  • When using it on data-object such as ITypedItem the fallback does not change the behavior of required.
    So if you don't change required, and the field doesn't exist, it will throw an error.
  • When using the MyModel the fallback will also affect the required.
    So if you specify a fallback which can be distinguished from the default (eg. not a null on a string, not a false on a bool) then required will be ignored and the fallback will be returned.

History

  • First introductions in 2sxc 16.03

Shortlink: https://go.2sxc.org/immutable

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