About this plugin
Locations are a custom post type with an address and coordinates. A visitor
types a place, picks a radius, and gets the nearest locations as pins on a map
and as a list beside it. It ships as a shortcode and as a Bricks Builder
element.
What it does
- Search by address, postcode or city, with suggestions as you type and a
search button beside the field
- A radius filter in kilometres or miles, and a result-count filter
- “Use my location”, which asks the browser for a position only when the
visitor presses the button
- A category filter, backed by a taxonomy
- Marker clustering, which switches itself on once a locator would draw fifty
pins, and which can be forced on or off
- A directions link from a result to OpenStreetMap or to Google Maps, or none
at all, whichever the site chooses
- Bulk geocoding from the admin, with a report of what happened to each row
- A settings screen whose fields are a closed list of options rather than a
free-text box that can hold anything
How it is built
- No dependencies and no build step. No npm, no Composer, no bundler. What
is in the plugin is what runs.
- No jQuery. One frozen window.SLOSM namespace on the front end.
- The REST API rather than admin-ajax. Four narrow, read-only routes.
- Conditional assets. The clustering bundle downloads only when a locator
actually needs it; a site with twenty branches never sees it.
- Geocoding through a server-side proxy, with a thirty-day cache and a
one-request-per-second gap, so a visitor’s browser never talks to the
geocoder itself and a failure is never cached.
- Leaflet and Leaflet.markercluster are bundled rather than loaded from a CDN.
Known limitations in this release
Worth reading before this goes on a site that matters.
- The search button is new in this release, and there is no form around
it. The address field has a Search button beside it now, running the same
search Enter runs; with the suggestion list open, both take the highlighted
suggestion rather than looking the text up again. What this markup
deliberately does not have is a <form>: that would make Enter submit the
page for anybody the plugin’s JavaScript has not reached yet, and a form
inside a page builder’s own form is discarded by the browser’s parser with
its controls handed to the outer one. If your theme or builder rebuilds the
filter bar and drops the button, the field still searches on Enter.
- The styling is two files, and you can switch one of them off. One holds
the layout — the map’s box and its height floor, the results list beside or
under it, the suggestion popup, the dot marker — and is always loaded. The
other is a skin: the spacing of the filter row and a border and padding on
the search field, the selects and the buttons, in the site’s own font and
colour rather than the browser’s. Untick “Default styles” on the Advanced tab
to drop the skin and write your own; the map keeps its layout either way, so
switching it off cannot leave you with a map of no height, which is the usual
way this kind of plugin appears broken.
- The accessibility and translation passes are done; what is left is
checking them with real software. The search field is a combobox with a
listbox of suggestions, the arrow keys walk it, one status line announces
what happened — including how many locations a search found — and opening a
location’s bubble moves the keyboard focus into it and gives it back when the
bubble closes. The map’s close button is labelled in your site’s language
rather than in English. None of that has been through NVDA, VoiceOver or
Orca yet, and that check is listed as open rather than claimed as done.
- One thing is deliberately left alone: the name inside a location’s bubble is
bold text and not a heading, because a heading needs a level and the right
level depends on the page you drop the locator into.
- Clustering at scale has not been measured on a real site either.
The free services have limits, and a busy shop will meet them
The public OpenStreetMap geocoding service allows roughly one request a second
and asks that heavy use go elsewhere. This plugin keeps to that limit and
caches hard, but a shop with real traffic needs its own instance or a paid
provider. That is a property of a free public service rather than of this
plugin, and the endpoints are settings so a site can point at its own.
Credits and licences
- Leaflet 1.9.4, unmodified, BSD-2-Clause — https://leafletjs.com/
- Leaflet.markercluster 1.5.3, unmodified, MIT —
markercluster
- Map data © OpenStreetMap contributors —
org/copyright
Both bundled libraries are GPL-compatible, and each ships with its own licence
file and a note recording where it came from and what its SHA-512 digest is.
A note on the name
OpenStreetMap is a trademark of the OpenStreetMap Foundation. This plugin is an
independent piece of software that works with OpenStreetMap data and services;
it is not endorsed by, affiliated with, or an official product of the
OpenStreetMap Foundation. The name follows the Foundation’s trademark policy,
which permits naming software that works specifically with OpenStreetMap data,
and asks for exactly this disclaimer alongside it.
markercluster are bundled here under their own licences and
are likewise not affiliated with this plugin’s author.
External services
This plugin contacts three external services. Two of them are contacted by
your server; the third is contacted by every visitor’s browser. None of them
is contacted until something on the site actually asks for it.
1. Nominatim, the OpenStreetMap geocoding service
What it is for. Turning an address into coordinates.
When. When a location is saved with an address and no coordinates, when
the bulk geocoder is run from the admin, and when a visitor submits a search.
A result is cached for thirty days, so the same address is sent once.
What is sent. The address or search text, normalised; an ISO country code
when the site has set one; and a User-Agent naming this plugin, its version
and your site’s home URL, which the service’s usage policy asks for. The
request is made by your server, so the visitor’s IP address and cookies are
not part of it.
Where. org/search by default. The
endpoint is a setting: a site may point it at its own instance or at a paid
provider instead.
Terms and privacy. Nominatim Usage Policy:
org/policies/nominatim/. Privacy policy of
the OpenStreetMap Foundation, which operates the service:
org/wiki/Privacy_Policy.
2. Photon, the address-suggestion service
What it is for. The suggestions that appear while a visitor types in the
search field.
When. While typing, after a pause, and only when suggestions are switched
on. A suggestion list is cached for a day.
What is sent. The text typed so far and a result limit. As above, the
request is made by your server rather than by the visitor’s browser.
Where. io/api by default, and also a setting.
Terms and privacy. Photon is run by komoot. Its terms are a fair-use
io/, which reads:
“You can use the API for your project, but please be fair – extensive usage
will be throttled. We do not guarantee for the availability and usage might be
” The service publishes no privacy policy of
its own, which is said here rather than papered over with a link to something
else. A site that needs a documented data-processing agreement for this should
point the setting at its own Photon instance, or switch suggestions off.
3. The OpenStreetMap tile server
What it is for. The map images themselves.
When. Every time a page carrying a map is viewed, from the visitor’s own
browser.
What is sent. What any image request sends: the visitor’s IP address, their
browser’s User-Agent, and the coordinates of the tiles being looked at. This
plugin sets no cookie of its own and neither the geocoding nor the suggestion
request carries one.
Where. png by default, and a
setting, so a site may use any tile provider it has the right to use.
Terms and privacy. Map data and attribution:
org/copyright. Tile Usage Policy:
org/policies/tiles/. Privacy policy of the
org/wiki/Privacy_Policy.
Not a request, but worth saying
A “directions” link opens OpenStreetMap, or Google Maps if the site chose
that, in a new tab when a visitor clicks it. Nothing is sent anywhere until
they do, and the link can be turned off in the settings.