How deeply does API Design Patterns cover type field?

Defines string validation, filtering, creation, and mutation risks, but defers subtype content storage.

Type field

A type field is a resource field that identifies which subtype or representation applies to a polymorphic resource instance.

A type field identifies which subtype or representation applies to a polymorphic resource instance. Use a validated string rather than an enumeration, so clients can filter and create resources through the same field. section 16.3.2

Message filtering and creation

A Message resource can expose type values such as text, photo, audio, and video. ListMessages() can filter for type = photo, while CreateMessage() accepts the appropriate shape and type value. section 16.3.2

Treat the field as a stable discriminator:

Validate string values against the supported subtype set. section 16.3.2
Avoid changing an existing resource from one type to another; relationships may rely on its original shape. section 16.3.2

How API Design Patterns covers it

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Related concepts

polymorphic resourcepart of · A polymorphic resource is an API resource whose generic interface can represent multiple specific resource implementations with implementation-dependent behavior.
attributekind of · An attribute is a named property, value, or piece of information associated with an entity, object, or program element.
enumalternative to · An enum is a type or language construct whose values are selected from a finite set of named alternatives, which may carry associated data.
content fieldconfigures · A content field is a resource field whose meaning and value structure represent the content associated with a resource subtype.
cryptographic keypart of · A cryptographic key is a value supplied to a cryptographic algorithm to control operations such as encryption, decryption, signing, authentication, or verification.
validationconfigures · The process of checking data, behavior, systems, models, or results against defined criteria to assess their correctness, suitability, or acceptability.

This explainer was generated by Manning's knowledge graph from the text of API Design Patterns. The section links point to the parts of the book it draws on.