Mapping ActivityPub Places objects and location attributes to WordPress geotagging.

[Jiwoon-Kim]

still in the data collection stage.

Activitypub
https://www.w3.org/TR/activitystreams-vocabulary/#places
https://www.w3.org/TR/activitystreams-vocabulary/#dfn-location
https://www.w3.org/TR/activitystreams-vocabulary/#dfn-travel
https://www.w3.org/TR/activitystreams-vocabulary/#dfn-arrive
https://www.w3.org/TR/activitystreams-vocabulary/#dfn-place
https://www.w3.org/TR/activitystreams-vocabulary/#dfn-radius
accuracy | altitude | latitude | longitude | radius | units

WordPress
https://wordpress.com/support/geotagging/
https://codex.wordpress.org/Geodata
https://wordpress.org/plugins/geolocation/
https://codex.wordpress.org/Custom_Queries

https://en.wikipedia.org/wiki/Geotagging
https://core.trac.wordpress.org/ticket/9257 EXIF GPS data

https://codex.wordpress.org/Talk:Geodata
https://lists.automattic.com/pipermail/wp-hackers/2010-June/032305.html
Automattic/jetpack#41773
https://core.trac.wordpress.org/ticket/52249 Events: Show user multiple location choices to disambiguate
https://core.trac.wordpress.org/ticket/53727

https://wordpress.com/support/post-by-email/#shortcodes
[geotag on | off] – override your geotagging privacy defaults to enable or disable the showing of geo information

https://socialhub.activitypub.rocks/t/how-to-represent-places-in-an-event/413

[Jiwoon-Kim]

Sure! Here's your text translated and adapted into English while keeping the technical detail intact:

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At this stage, we are in the “data collection and conceptual mapping” phase (WordPress geotagging ↔ ActivityPub Places). The first step is to systematically organize the schema structures and their semantic correspondences (mapping). Below is a first draft of a technical comparison table, integrated mapping, and implementation considerations. This can be developed into a formal document later.

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🧭 1️⃣ ActivityPub / ActivityStreams Vocabulary: Place Attributes Summary

Attribute	Description	Data Type	Example
type	Always "Place"	String	"Place"
name	Name of the place	String	"Busan, South Korea"
id	URI (unique identifier)	URL	"https://travel-in-busan.com/place/gwangalli"
latitude	Latitude	Float	35.1535
longitude	Longitude	Float	129.1187
altitude	Altitude	Float (optional)	12.5
accuracy	Accuracy in meters	Float	20
radius	Radius around the location	Float	1000
units	Distance unit (default m)	String	"m", "ft"
url	Map or external resource URL	URL	"https://maps.google.com/?q=35.1535,129.1187"
relatesTo / partOf	Higher-level geographical object (e.g., Gwangalli → Busan)	Place (nested)	—

💡 Notes:

• A Place can exist as a standalone object or be included in an Activity’s location property.
• Related Activities include Travel, Arrive, Leave, Move, Visit.

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🌏 2️⃣ WordPress Geotagging & Geodata Structure Summary

WordPress typically handles location information as post meta (custom fields). Common meta keys include:

Meta Key	Meaning	Example
_geo_latitude	Latitude	35.1535
_geo_longitude	Longitude	129.1187
_geo_public	Visibility	1 (public) / 0 (private)
_geo_address	Address	"Gwangalli Beach, Busan"
_geo_city	City	"Busan"
_geo_country	Country	"South Korea"
_geo_region	Region / District	"Suyeong-gu"
_geo_accuracy	Accuracy	20
_geo_altitude	Altitude	12.5
_geo_radius	Radius	1000
_geo_units	Unit	"m"

Sources / references:

• WordPress Codex: Geodata
• Jetpack geolocation module
• Plugins: geolocation, simple-location, wp-geo

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🧩 3️⃣ Mapping Table (ActivityPub ↔ WordPress)

ActivityPub / AS2	WordPress Meta	Notes / Mapping Details
Place.id	get_permalink($post) or custom URI	Unique identifier URI
Place.name	_geo_address or _geo_city	Place name / address
Place.latitude	_geo_latitude	Latitude
Place.longitude	_geo_longitude	Longitude
Place.altitude	_geo_altitude	Altitude
Place.accuracy	_geo_accuracy	Measurement accuracy
Place.radius	_geo_radius	Radius around place
Place.units	_geo_units	Distance unit
Place.url	_geo_map_link	Map URL (optional)
location (Activity property)	_geo_* set	Complete location info for a post
summary / name	post_title	Optional: include place name in post title

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🏗️ 4️⃣ Implementation Considerations

① Data Sources

• EXIF → post meta auto-fill possible via wp_read_image_metadata filter
• Jetpack / Simple Location plugins already support _geo_* meta
• REST API extension: /wp-json/wp/v2/posts/<id>?_fields=geo

② ActivityPub Plugin Extension

Current ActivityPub plugins focus on actor / object; Place support is partial.

• Extend activitypub\transformer\Post class to add location property
• Serialize Place objects into JSON-LD for the post

Example JSON-LD:

{
  "type": "Note",
  "content": "I walked along Gwangalli Beach today.",
  "location": {
    "type": "Place",
    "name": "Gwangalli Beach",
    "latitude": 35.1535,
    "longitude": 129.1187,
    "accuracy": 15,
    "radius": 200,
    "units": "m"
  }
}

③ Activity Types (Travel, Arrive)

• Travel: tracks user movement
• Arrive / Leave: record location at a specific time
• Can hook into save_post / post_modified to generate corresponding ActivityPub Activities

④ Privacy Considerations

• Use [geotag on | off] shortcode or _geo_public meta
• Synchronize ActivityPub visibility (public / followers-only) with local geoprivacy

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🧠 5️⃣ Future Exploration

Goal	References / Implementation Points
📍 Include Place object in ActivityPub Note	activitypub-transformer filter
🗺️ GeoJSON export	REST endpoint extension (/geojson)
📸 EXIF → geodata automatic conversion	wp_generate_attachment_metadata hook
🔐 Geo privacy management UI	_geo_public ↔ post visibility integration
🌐 Fediverse mapping / travel logging	Travel, Arrive, Place → MapView implementation

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Suggested Next Steps

• Visualize the WordPress ↔ ActivityPub Place mapping including JSON-LD structure
• Prototype a transformer class to output location objects from post meta
• Consider performance for posts with many geo-tagged images or multi-version attachments

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If you want, I can create a diagram showing WordPress → ActivityPub Place object mapping, including meta keys, JSON-LD output, and ActivityPub activity relations. This can help visualize the geotagging workflow for federated posts.

Do you want me to do that?