Merge remote-tracking branch 'upstream/master'

[nominatim.git] / docs / api / Output.md

diff --git a/docs/api/Output.md b/docs/api/Output.md
index 5a33942034d4d49c41145cf02e9f8dbd0f62f571..2f9bdaebe98fa7b4958587f2f7f2871ac4db745c 100644 (file)
--- a/docs/api/Output.md
+++ b/docs/api/Output.md
@@ -1,6 +1,6 @@
 # Place Output
 
 # Place Output
 

-The [\reverse](Reverse.md), [\search](Search.md) and [\lookup](Lookup.md)
+The [/reverse](Reverse.md), [/search](Search.md) and [/lookup](Lookup.md)

 API calls produce very similar output which is explained in this section.
 There is one section for each format which is selectable via the `format`
 parameter.
 API calls produce very similar output which is explained in this section.
 There is one section for each format which is selectable via the `format`
 parameter.


@@ -46,9 +46,9 @@ a single place (for reverse) of the following format:
 
 The possible fields are:
 
 
 The possible fields are:
 

- * `place_id` - reference to the Nominatim internal database ID
+ * `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))

  * `osm_type`, `osm_id` - reference to the OSM object
  * `osm_type`, `osm_id` - reference to the OSM object

- * `boundingbox` - area of corner coordinates
+ * `boundingbox` - area of corner coordinates ([see notes](#boundingbox))

  * `lat`, `lon` - latitude and longitude of the centroid of the object
  * `display_name` - full comma-separated address
  * `class`, `type` - key and value of the main OSM tag
  * `lat`, `lon` - latitude and longitude of the centroid of the object
  * `display_name` - full comma-separated address
  * `class`, `type` - key and value of the main OSM tag


@@ -70,12 +70,12 @@ This is the same as the JSON format with two changes:
 
 ### GeoJSON
 
 
 ### GeoJSON
 

-This format follows the [RFC7946](http://geojson.org). Every feature includes
+This format follows the [RFC7946](https://geojson.org). Every feature includes

 a bounding box (`bbox`).
 
 The feature list has the following fields:
 
 a bounding box (`bbox`).
 
 The feature list has the following fields:
 

- * `place_id` - reference to the Nominatim internal database ID
+ * `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))

  * `osm_type`, `osm_id` - reference to the OSM object
  * `category`, `type` - key and value of the main OSM tag
  * `display_name` - full comma-separated address
  * `osm_type`, `osm_id` - reference to the OSM object
  * `category`, `type` - key and value of the main OSM tag
  * `display_name` - full comma-separated address


@@ -83,7 +83,7 @@ The feature list has the following fields:
  * `importance` - computed importance rank
  * `icon` - link to class icon (if available)
  * `address` - dictionary of address details (only with `addressdetails=1`)
  * `importance` - computed importance rank
  * `icon` - link to class icon (if available)
  * `address` - dictionary of address details (only with `addressdetails=1`)

- * `extratags` - dictionary with additional useful tags like website or maxspeed
+ * `extratags` - dictionary with additional useful tags like `website` or `maxspeed`

    (only with `extratags=1`)
  * `namedetails` - dictionary with full list of available names including ref etc.
 
    (only with `extratags=1`)
  * `namedetails` - dictionary with full list of available names including ref etc.
 


@@ -100,12 +100,9 @@ The following feature attributes are implemented:
  * `type` - value of the main tag of the object (e.g. residential, restaurant, ...)
  * `label` - full comma-separated address
  * `name` - localised name of the place
  * `type` - value of the main tag of the object (e.g. residential, restaurant, ...)
  * `label` - full comma-separated address
  * `name` - localised name of the place

- * `housenumber`, `street`, `locality`, `postcode`, `city`,
-   `district`, `county`, `state`, `country` -
+ * `housenumber`, `street`, `locality`, `district`, `postcode`, `city`,
+   `county`, `state`, `country` -

    provided when it can be determined from the address
    provided when it can be determined from the address

-   (see [this issue](https://github.com/openstreetmap/Nominatim/issues/1080) for
-   current limitations on the correctness of the address) and `addressdetails=1`
-   was given

  * `admin` - list of localised names of administrative boundaries (only with `addressdetails=1`)
 
 Use `polygon_geojson` to output the full geometry of the object instead
  * `admin` - list of localised names of administrative boundaries (only with `addressdetails=1`)
 
 Use `polygon_geojson` to output the full geometry of the object instead


@@ -120,7 +117,7 @@ formats depending on the API call.
 
 ```
 <reversegeocode timestamp="Sat, 11 Aug 18 11:53:21 +0000"
 
 ```
 <reversegeocode timestamp="Sat, 11 Aug 18 11:53:21 +0000"

-                attribution="Data © OpenStreetMap contributors, ODbL 1.0. http://www.openstreetmap.org/copyright"
+                attribution="Data © OpenStreetMap contributors, ODbL 1.0. https://www.openstreetmap.org/copyright"

                 querystring="lat=48.400381&lon=11.745876&zoom=5&format=xml">
   <result place_id="179509537" osm_type="relation" osm_id="2145268" ref="BY"
           lat="48.9467562" lon="11.4038717"
                 querystring="lat=48.400381&lon=11.745876&zoom=5&format=xml">
   <result place_id="179509537" osm_type="relation" osm_id="2145268" ref="BY"
           lat="48.9467562" lon="11.4038717"


@@ -148,13 +145,13 @@ attribution to OSM and the original querystring.
 
 The place information can be found in the `result` element. The attributes of that element contain:
 
 
 The place information can be found in the `result` element. The attributes of that element contain:
 

- * `place_id` - reference to the Nominatim internal database ID
+ * `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))

  * `osm_type`, `osm_id` - reference to the OSM object
  * `ref` - content of `ref` tag if it exists
  * `lat`, `lon` - latitude and longitude of the centroid of the object
  * `osm_type`, `osm_id` - reference to the OSM object
  * `ref` - content of `ref` tag if it exists
  * `lat`, `lon` - latitude and longitude of the centroid of the object

- * `boundingbox` - comma-separated list of corner coordinates
+ * `boundingbox` - comma-separated list of corner coordinates ([see notes](#boundingbox))

 
 

-The full address address of the result can be found in the content of the
+The full address of the result can be found in the content of the

 `result` element as a comma-separated list.
 
 Additional information requested with `addressdetails=1`, `extratags=1` and
 `result` element as a comma-separated list.
 
 Additional information requested with `addressdetails=1`, `extratags=1` and


@@ -164,12 +161,12 @@ Additional information requested with `addressdetails=1`, `extratags=1` and
 
 ```
 <searchresults timestamp="Sat, 11 Aug 18 11:55:35 +0000"
 
 ```
 <searchresults timestamp="Sat, 11 Aug 18 11:55:35 +0000"

-               attribution="Data © OpenStreetMap contributors, ODbL 1.0. http://www.openstreetmap.org/copyright"
+               attribution="Data © OpenStreetMap contributors, ODbL 1.0. https://www.openstreetmap.org/copyright"

                querystring="london" polygon="false" exclude_place_ids="100149"
                more_url="https://nominatim.openstreetmap.org/search.php?q=london&addressdetails=1&extratags=1&exclude_place_ids=100149&format=xml&accept-language=en-US%2Cen%3Bq%3D0.7%2Cde%3Bq%3D0.3">
   <place place_id="100149" osm_type="node" osm_id="107775" place_rank="15"
          boundingbox="51.3473219,51.6673219,-0.2876474,0.0323526" lat="51.5073219" lon="-0.1276474"
                querystring="london" polygon="false" exclude_place_ids="100149"
                more_url="https://nominatim.openstreetmap.org/search.php?q=london&addressdetails=1&extratags=1&exclude_place_ids=100149&format=xml&accept-language=en-US%2Cen%3Bq%3D0.7%2Cde%3Bq%3D0.3">
   <place place_id="100149" osm_type="node" osm_id="107775" place_rank="15"
          boundingbox="51.3473219,51.6673219,-0.2876474,0.0323526" lat="51.5073219" lon="-0.1276474"

-         display_name="London, Greater London, England, SW1A 2DU, United Kingdom" 
+         display_name="London, Greater London, England, SW1A 2DU, United Kingdom"

          class="place" type="city" importance="0.9654895765402"
          icon="https://nominatim.openstreetmap.org/images/mapicons/poi_place_city.p.20.png">
     <extratags>
          class="place" type="city" importance="0.9654895765402"
          icon="https://nominatim.openstreetmap.org/images/mapicons/poi_place_city.p.20.png">
     <extratags>


@@ -203,11 +200,11 @@ generic information about the query:
 The place information can be found in the `place` elements, of which there may
 be more than one. The attributes of that element contain:
 
 The place information can be found in the `place` elements, of which there may
 be more than one. The attributes of that element contain:
 

- * `place_id` - reference to the Nominatim internal database ID
+ * `place_id` - reference to the Nominatim internal database ID ([see notes](#place_id-is-not-a-persistent-id))

  * `osm_type`, `osm_id` - reference to the OSM object
  * `ref` - content of `ref` tag if it exists
  * `lat`, `lon` - latitude and longitude of the centroid of the object
  * `osm_type`, `osm_id` - reference to the OSM object
  * `ref` - content of `ref` tag if it exists
  * `lat`, `lon` - latitude and longitude of the centroid of the object

- * `boundingbox` - comma-separated list of corner coordinates
+ * `boundingbox` - comma-separated list of corner coordinates ([see notes](#boundingbox))

  * `place_rank` - class search rank
  * `display_name` - full comma-separated address
  * `class`, `type` - key and value of the main OSM tag
  * `place_rank` - class search rank
  * `display_name` - full comma-separated address
  * `class`, `type` - key and value of the main OSM tag


@@ -220,3 +217,34 @@ as subelements with the type of the address part.
 Additional information requested with `extratags=1` and `namedetails=1` can
 be found in extra elements as sub-element of each place.
 
 Additional information requested with `extratags=1` and `namedetails=1` can
 be found in extra elements as sub-element of each place.
 

+
+## Notes on field values
+
+### place_id is not a persistent id
+
+The `place_id` is created when a Nominatim database gets installed. A
+single place will have a different value on another server or even when
+the same data gets re-imported. It's thus not useful to treat it as
+permanent for later use.
+
+The combination `osm_type`+`osm_id` is slighly better but remember in
+OpenStreetMap mappers can delete, split, recreate places (and those
+get a new `osm_id`), there is no link between those old and new ids.
+Places can also change their meaning without changing their `osm_id`,
+e.g. when a restaurant is retagged as supermarket. For a more in-depth
+discussion see [Permanent ID](https://wiki.openstreetmap.org/wiki/Permanent_ID).
+
+Nominatim merges some places (e.g. center node of a city with the boundary
+relation) so `osm_type`+`osm_id`+`class_name` would be more unique.
+
+### boundingbox
+
+Comma separated list of min latitude, max latitude, min longitude, max longitude.
+The whole planet would be `-90,90,-180,180`.
+
+Can we used to pan and center the map on the result, for example with leafletjs
+mapping library
+`map.fitBounds([[bbox[0],bbox[2]],[bbox[1],bbox[3]]], {padding: [20, 20], maxzoom: 16});`
+
+Bounds crossing the antimeridian have a min latitude -180 and max latitude 180,
+essentially covering the planet (See [issue 184](https://github.com/openstreetmap/Nominatim/issues/184)).