---
title: "Field Representation"
description: "The following guidelines apply for the values of object fields in the API (see Field Types for the full list of field types supported by JourneyApps)."
permalink: /docs/backend-api/api-reference/field-representation/
---
# Field Representation
The following guidelines apply for the values of object fields in the API (see [Field Types](/docs/build/data-model-configuration/model/field/) for the full list of field types supported by JourneyApps).
| Type | Format returned in API response | Format accepted for create and update |
| --- | --- | --- |
| `text` | The text in standard JSON. Example: `"Nokia"` | Any string in standard JSON format. Example: `"Nokia"` |
| `integer` | The number in standard JSON format. Example: `42`. | Any integer in standard JSON format. Example: `42`. |
| `number` | The number in standard JSON format. Example: `3.1428`. | Any decimal number in standard JSON format. Example: `3.1428`. |
| `date` | A date in the format `YYYY-MM-DD`, as defined by the [ISO 8601](http://en.wikipedia.org/wiki/ISO_8601) specification. Example: `"2016-02-27"`. | Any valid date according to the [ISO 8601](http://en.wikipedia.org/wiki/ISO_8601) specification. Any time or timezone components will be stripped. The `YYYY-MM-DD` format is recommended. Example: `"2016-02-27"` |
| `datetime` | A date and time in the format `YYYY-MM-DDTHH:MM:SSZ`, as defined by the [ISO 8601](http://en.wikipedia.org/wiki/ISO_8601) specification. Note that the time is specified in the UTC/GMT timezone. Example: `"2016-02-22T14:00:53Z"`. | Any valid date and time according to the [ISO 8601](http://en.wikipedia.org/wiki/ISO_8601) specification. The `YYYY-MM-DDTHH:MM:SSZ` format is recommended. Example: `"2016-02-22T14:00:53Z".` |
| `single-choice` | The key and display label of option. Example: `{"key": "soccer", "display": "Soccer"}` | The string key of the option. Example: `"soccer"` |
| `single-choice-integer` | The key and display label of option. Example: `{"key": 3, "display": "Soccer"}` | The integer key of the option. Example: `3` |
| `boolean` | The key and display label of option. Example: `{"key": true, "display": "Yes"}` | The boolean key of the option. Example: `true` |
| `multiple-choice` | An array of keys and display labels of the selected options. Example: `[{"key": "soccer", "display": "Soccer"}, {"key": "tennis", "display": "Tennis"}]` | An array of keys, as explained above. Example: `["soccer", "tennis"]`. |
| `multiple-choice-integer` | An array of keys and display labels of the selected options. Example: `[{"key": 3, "display": "Soccer"}, {"key": 4, "display": "Tennis"}]` | An array of keys, as explained above. Example: `[3, 4]`. |
| `location` | Hash with fields *latitude*, *longitude*, *altitude*, *horizontal accuracy*, *vertical accuracy* and *timestamp*. Note that *altitude* and *vertical accuracy* are typically not reported by mobile devices, and only *latitude* and longitude can currently be edited on the JourneyApps Backend data browser. The *timestamp* is automatically populated when the location is captured. See: [Location API Response Example](#location-api-response-example) | A hash with fields *latitude* and *longitude* (both decimal numbers), and optionally *altitude*, *horizontal accuracy*, *vertical accuracy* (all decimal numbers) and *timestamp* (a date and time in the format `YYYY-MM-DDTHH:MM:SSZ`, as defined by [ISO 8601](http://en.wikipedia.org/wiki/ISO_8601)). Leaving the *timestamp* blank will cause the current time to be used. If you update an existing GPS *location* and omit the *altitude*, *horizontal accuracy* or *vertical accuracy* fields, any existing values in those fields will be set to `null`. See: [Location API Update Object Example](#location-api-update-object-example) |
| `attachment` | A hash with fields *state*, *id* and *original*. The attachment's object id is a separate field, where the key is the attachment's field name plus `_id`. See: [Attachment API Response Example](#attachment-api-response-example) | A hash with fields *base64*, containing the [Base64](http://en.wikipedia.org/wiki/Base64) representation of the attachment file, and *filename*, containing the name of the file. See: [Attachment API Update Object Example](#attachment-api-update-object-example) |
| Photos | A hash with fields *state*, *thumbnail*, *fullscreen* and *original*. The photo's object id is a separate field, where the key is the photo's field name plus `_id`. See: [Photos API Response Example](#photos-api-response-example) | A hash with fields *base64*, containing the [Base64](http://en.wikipedia.org/wiki/Base64) representation of the attachment file, and *filename*, containing the name of the file. See: [Photos and signatures API Update Object Example](#photos-and-signatures-api-update-object-example) |
| Signatures | A hash with fields *state*, *thumbnail*, *fullscreen*, *original* and *svg*. The signature's object id is a separate field, where the key is the signature's field name plus `_id`. See: [Signatures API Response Example](#signatures-api-response-example) | A hash with fields *base64*, containing the [Base64](http://en.wikipedia.org/wiki/Base64) representation of the attachment file, and *filename*, containing the name of the file. See: [Photos and signatures API Update Object Example](#photos-and-signatures-api-update-object-example) |
| Relationships | Relationships use the relationship name plus `_id` as the key, with the related object id as the value. Only *belongs to* relationships are included in the object itself, *has many* relationships should be queried and/or set from the other side of the relationship. Example: `building_id: "9913706a-179b-11e2-aaff-0026189d9dc0"`. | The same format is used for setting relationships. Example: `building_id: "9913706a-179b-11e2-aaff-0026189d9dc0"`. |
### Examples
#### Location API Response Example
```json
{
"latitude": -33.913147447989644,
"longitude": 18.882385137695337,
"altitude": null,
"horizontal_accuracy": null,
"vertical_accuracy": null,
"timestamp": "2013-02-22T14:00:53Z"
}
```
#### Location API Update Object Example
```json
{
"latitude": -33.913147447989644,
"longitude": 18.882385137695337,
"altitude": 16.43133544921875,
"horizontal_accuracy": 10.0,
"vertical_accuracy": 6.0,
"timestamp": "2014-06-22T13:45:39Z"
}
```
#### Attachment API Response Example
```json
"sample_file_id": "ffca93d4-690c-4563-9d38-42c97b51443b",
"sample_file": {
"state": "uploaded",
"original": "https://run.journeyapps.com/media/W1siZiI/sample.pdf?sha=ee3b"
}
```
#### Attachment API Update Object Example
```json
sample_file: {
"base64": "iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==",
"filename": "cover-letter.pdf"
}
```
**Note**: `base64` must not contain any newline characters.
Only the following characters are allowed in `filename`:
* Lowercase alphanumeric characters
* Under score (`_`), hyphen (`-`), period (`.`) and space ( )
#### Photos API Response Example
```json
"sample_photo_id": "ffca93d4-690c-4563-9d38-42c97b51443b",
"sample_photo": {
"state": "uploaded",
"thumbnail": "https://run.journeyapps.com/media/W1siZd/photo-2021Z.jpg?sha=9b16",
"fullscreen": "https://run.journeyapps.com/media/W1siZQ/photo-2021Z.jpg?sha=70dc",
"original": "https://run.journeyapps.com/media/W1siZw/photo-2021Z.jpg?sha=5085"
}
```
**Note**: The *state* field can be `uploaded`,`pending`, `missing`, or `untrusted`. The *thumbnail*, *fullscreen* and *original* fields are only present if state is `uploaded`.
#### Signatures API Response Example
```json
"sample_signature_id": "ffca93d4-690c-4563-9d38-42c97b51443b",
"sample_signature": {
"state": "uploaded",
"thumbnail": "https://run.journeyapps.com/media/W1siK0/signature-2021Z.svg?sha=48b3",
"fullscreen": "https://run.journeyapps.com/media/W1siZiIsI/signature-2021Z.svg?sha=7231",
"original": "https://run.journeyapps.com/media/W1siZiIsI/signature-2021Z.svg?sha=7231",
"svg": "https://run.journeyapps.com/media/W1siZQ/signature-2021Z.svg?sha=28f"
}
```
**Note**: The *state* field can be `uploaded` or `pending`. The *thumbnail*, *fullscreen*, *original* and *svg* fields are only present if state is `uploaded`.
#### Photos and signatures API Update Object Example
```json
photo: {
"base64": "iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==",
"filename": "small-red-dot.png"
}
```
**Note**: `base64` must not contain any newline characters.
Only the following characters are allowed in `filename`:
* Lowercase alphanumeric characters
* Under score (`_`), hyphen (`-`), period (`.`) and space ( )
### Values Not Present
When retrieving objects, a field not present should be interpreted the same as a `null` value for that field. This applies to all field types, as well as relationships.
When updating an object with Update a Single Object, setting the field to `null` will clear that field. On the other hand, omitting the field will leave its value unchanged. This applies to all field types, as well as relationships.