We previously showed how to create a simple map of pubs using Overpass to extract data from OpenStreetMap and uMap to display the data on a simple zoomable map. In this short update we show how to manipulate the data so that all pubs are shown as points of interest rather than a mixture of points and polygons.

This update article follows on directly from our previous article on creating an always up to date map using Overpass to extract data from OpenStreetMap and uMap to display the data on a simple zoomable map. We encourage you to read that earlier article before proceeding. In the comments I noted that I did not like how some of the data was shown as points, whilst the rest of the data was shown as polygons. Thanks to Martin Raifer (osmtogeojson) and Yohan Boniface (uMap) we can now fix that problem!

It turns out that Overpass was already able to return the centroids of polygons via use of the center output, however uMap did not yet understand the outputs. Being open source data I requested that the functionality be added to uMap. This meant first adding the functionality to osmtogeojson, the data library that uMap uses to understand OpenStreetMap data. This was achieved within a matter of days and following a quick update to uMap we’re all set to go. Let see how it works:

• We follow the same steps as per our earlier article. Read more here.
• At step 5 we use the following adjusted Overpass data call instead (note the “center” part that requests centroid data from OpenStreetMap):
  http://overpass-api.de/api/interpreter?data=[out:json][timeout:25];node[“amenity”=”pub”]({south},{west},{north},{east});out qt;way[“amenity”=”pub”]({south},{west},{north},{east});out body center;>;out skel qt;

It’s as simple as that! Let see the result:

We think it looks great, and a lot more consistent than the mixed point and polygon map.

Update: Pop-up data

I have been asked to show how to add pop-up data to the map points. This obviously requires the data to already exist in OpenStreetMap. Assuming it does it simple to add this data:

1. In uMap click the layers button (just under +/- ) and then click Edit (the pencil symbol).
2. In the right hand pane scroll down to the Popup content template section of the Advanced Options.
3. To add the pubs name and address to the pop-up simply edit this text box to include the following (based on the OpenStreetMap tags):
   # {name}
   {addr:street}
   {addr:city}

Note that only a few pubs are tagged with their full address in Stratford-upon-Avon so you may have to click on a few on the map above before you get a pop-up with all this data shown.

In the previous post we showed that creating a map to show location data as a collection of pins (map markers) is easy using OpenStreetMap tools. But what if we wanted to keep that map up to date? In this article we’ll show how we keep our pubs map always up to date.

The landscape around is is always changing. Sometimes the changes are big and obvious, for example a new housing development, but changes can also be as subtle as a change in shop name. OpenStreetMap, which is commonly referred to as the wikipedia of maps, provides map data collected by a community of mappers. It emphasises local knowledge, with contributors keeping their local area up to date on the map. It is therefore the perfect source not only for the background base map, but also for the data we display on top of the base map.

Contributors use aerial imagery, GPS devices, and low-tech field maps to verify that OSM is accurate and up to date.

In the previous post we saw how uMap could be used to display map data in just the same way as Google Maps Engine/Fusion Tables. We have also previously seen how we can use Overpass to download data from OpenStreetMap. The uMap tool lets us link to Overpass to produce an always up to date map. Lets see how:

Map tutorial

Pubs are currently closing at a rate of 31 per week (source). Lets update our pubs map so that it’s automatically kept up to date by local OpenStreetMap contributors. As a secondary benefit the map will now work globally rather than just for Stratford-upon-Avon and surrounding land.

1. Head to overpass-turbo.eu.
2. Click Wizard and search for amenity=pub (learn about OpenStreetMap tags here)
3. Click Export, Query, and then download/copy as umap remote data url.
4. Paste the copied text in to a notepad and add “http://overpass-api.de/api/interpreter?data=” without quotes before it.
   1. The final result should look like:
      http://overpass-api.de/api/interpreter?data=[out:json][timeout:25];(node[“amenity”=”pub”]({south},{west},{north},{east});way[“amenity”=”pub”]({south},{west},{north},{east});relation[“amenity”=”pub”]({south},{west},{north},{east}););out body;>;out skel qt;
5. Now navigate to umap.openstreetmap.fr or one of the alternate instances listed here.
6. Click Create a map and pan/zoom in to the area of interest.
7. Click the layers button (just under the +/- buttons) and then click Edit (the pencil symbol).
   1. In the right hand pane click Remote data and paste the URL we constructed in step 5 into the Url box.
   2. Select “osm” from the drop down Format list.
   3. Tick the dynamic checkbox.
   4. Optional: If you have a lot of data you may want to limit the display to certain zoom levels (so as to not put too much strain on the Overpass servers). You can do this by entering a min zoom level in the From Zoom box. Here I have entered 13 as my minimal zoom level.
8. Customise using the options on the right. Here I’ve changed the map background to OSM monochrome and changed the colour of the overlay data.
9. Click More on the left hand side, followed by Embed and share this map.
10. Copy and paste the embeddable iframe (I also had to click Current view instead of default map view in the iframe options box.

The resulting map is shown below:

View full screen

Inspired to create your own map? Let us know what you make by posting a comment below or tweeting us on @mappamercia.