Work with coders and Codable models

reference australia Updated Sep 10, 2026 1 min read mobsdk-ios-work-coder-codable_mod.md

The iOS implementation of the Mobile SDK provides the additional functionality of coders and Codable models.

Coder enumeration

The Coder enumeration wraps a JSONEncoder with an accompanying JSONDecoder so that both provide the same coding strategy. Since many of the NowData framework APIs that handle Codable models rely on coding and decoding from JSON, the Coder simplifies and standardizes the way to specify encoders and decoders. Typically, using the default Coder (.default), which encodes and decodes dates using the nonISO8601UTC date formatting, is sufficient. The DateFormatter.nonISO8601UTC is a static date formatter provided by the NowData framework. It is responsible for encoding and decoding dates that were stored by the ServiceNow platform in the UTC (GMT+0) time zone, and are used by the Table API in yyyy-MM-dd HH:MM:SS format, by taking a device's locale and time zone into consideration.

If custom JSON coding is required, such as when handling specific date formats, you can create a custom Coder by supplying the custom JSONEncoder and JSONDecoder as the custom Coder's associated types. Both the encoder and decoder must use the same coding strategy.

For example:

JavaScript

let myEncoder = JSONEncoder()myEncoder.dateEncodingStrategy = .formatted(.nonISO8601UTC)let myDecoder = JSONDecoder()myDecoder.dateDecodingStrategy = .formatted(.nonISO8601UTC)
let myCoder: Coder = .custom(myEncoder, myDecoder)

Codable extension for nested structures

The NowData framework provides functionality to decode nested structures by dot-separated path. This functionality makes it easier to consume nested data by removing the necessity of using wrapper structure and nested JSON decoding.

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---
title: Work with coders and Codable models
description: The iOS implementation of the Mobile SDK provides the additional functionality of coders and Codable models.
locale: en-US
canonical_url: https://www.servicenow.com/docs/r/australia/api-reference/developer-guides/mobsdk-ios-work-coder-codable\_mod.html
release: australia
product: Developer Guides
classification: developer-guides
topic_type: reference
last_updated: "2026-09-10"
reading_time_minutes: 1
breadcrumb: [Mobile SDK Developer Guide - iOS, Developer guides, API implementation and reference]
---

# Work with coders and Codable models

The iOS implementation of the Mobile SDK provides the additional functionality of coders and Codable models.

## Coder enumeration

The `Coder` enumeration wraps a `JSONEncoder` with an accompanying `JSONDecoder` so that both provide the same coding strategy. Since many of the NowData framework APIs that handle Codable models rely on coding and decoding from JSON, the `Coder` simplifies and standardizes the way to specify encoders and decoders. Typically, using the default `Coder` \(`.default`\), which encodes and decodes dates using the `nonISO8601UTC` date formatting, is sufficient. The `DateFormatter.nonISO8601UTC` is a static date formatter provided by the NowData framework. It is responsible for encoding and decoding dates that were stored by the ServiceNow platform in the UTC \(GMT+0\) time zone, and are used by the Table API in `yyyy-MM-dd HH:MM:SS` format, by taking a device's locale and time zone into consideration.

If custom JSON coding is required, such as when handling specific date formats, you can create a custom `Coder` by supplying the custom `JSONEncoder` and `JSONDecoder` as the custom Coder's associated types. Both the encoder and decoder must use the same coding strategy.

For example:

```
let myEncoder = JSONEncoder()
myEncoder.dateEncodingStrategy = .formatted(.nonISO8601UTC)
let myDecoder = JSONDecoder()
myDecoder.dateDecodingStrategy = .formatted(.nonISO8601UTC)

let myCoder: Coder = .custom(myEncoder, myDecoder)
```

## Codable extension for nested structures

The NowData framework provides functionality to decode nested structures by dot-separated path. This functionality makes it easier to consume nested data by removing the necessity of using wrapper structure and nested JSON decoding.