addressPointMatch.md

Address Point Match Check

Description

This check identifies Point objects in OSM that have a specified street number (addr:housenumber) but no specified street name (addr:street). No specified street name refers to either having a null value for the street name key, or no street name key present at all.

Live Example

The following examples illustrate two cases where a Point has a street number but no street name in its tags.

1. This Point id:977597085 has a street number but no street name specified in the address.
2. This Point id:4552330391 has a street number but no street name specified in the address.

Code Review

In Atlas, OSM elements are represented as Edges, Points, Lines, Nodes & Relations; in our case, we’re are looking at Points with specified street numbers but no street name.

Our first goal is to validate the incoming Atlas object. Valid features for this check will satisfy the following conditions:

• Must be a valid Point object
• Must not be part of an associated street Relation
• Must have an address house number tag
• Must not have the addr:street tag, have the tag but with a null value, or have the tag but with no value

    @Override
        public boolean validCheckForObject(final AtlasObject object)
        {
            // Object is an instance of Point
            return object instanceof Point
                    // And does not have an Associated Street Relation
                    && !hasAssociatedStreetRelation(object)
                    // And has an AddressHouseNumberTag
                    && object.getTag(AddressHousenumberTag.KEY).isPresent()
                    // And either doesn't have the addr:street tag, has the tag but has a null value,
                    // or has the tag but has no value
                    && Strings.isNullOrEmpty(object.tag(AddressStreetTag.KEY));
        }

After the preliminary filtering of features, we need to find candidates for populating each feature's missing street name. We do this by drawing a bounding box, leveraging the boxAround(), around the Point of interest using a configurable bounds size parameter. Using these bounds, we can consider other Points that fall inside the bounds that have a specified street number and street name using pointsWithin(). If there are no other Points found within this bounding box, we next look at edges within or which intersect with our bounding box using edgesIntersecting(). If there are no Points or Edges within or intersecting our bounds, we still flag the problematic Point feature but with a specific instruction message indicating that no candidate street names were found. Otherwise, we flag the Point and list a Set of unique candidate street names in the instructions.

   @Override
      protected Optional<CheckFlag> flag(final AtlasObject object)
      {
          final Point point = (Point) object;
  
          // Get a bounding box around the Point of interest
          final Rectangle box = point.getLocation().boxAround(boundsSize);
  
          // Get all Points in the bounding box, remove Points that have null as their
          // street name or do not have the street name key tag, and get a set of candidate street
          // names
          final Set<String> points = Iterables.stream(point.getAtlas().pointsWithin(box))
                  .map(nearbyPoint -> nearbyPoint.tag(AddressStreetTag.KEY)).filter(Objects::nonNull)
                  .collectToSet();
  
          // Get all Edges intersecting the bounding box, remove Edges that have null as their
          // street name or do not have the street name key tag, and get a set of candidate street
          // names
          final Set<String> edges = Iterables.stream(point.getAtlas().edgesIntersecting(box))
                  .map(nearbyEdge -> nearbyEdge.tag(NameTag.KEY)).filter(Objects::nonNull)
                  .collectToSet();
  
          // If there are no Points or Edges in the bounding box
          if (points.isEmpty() && edges.isEmpty())
          {
              // Flag Point with instruction indicating that there are are no suggestions
              return Optional.of(this.createFlag(point,
                      this.getLocalizedInstruction(2, point.getOsmIdentifier())));
          }
          // If there are Points in the bounding box
          else if (!points.isEmpty())
          {
              // Add all interior Point street names to the list of candidate street names
              return Optional.of(this.createFlag(point,
                      this.getLocalizedInstruction(0, point.getOsmIdentifier(), points)));
          }
          // If there are Edges intersecting or contained by the bounding box
          else
          {
              return Optional.of(this.createFlag(point,
                      this.getLocalizedInstruction(1, point.getOsmIdentifier(), edges)));
          }
      }

To learn more about the code, please look at the comments in the source code for the check. AddressPointMatchCheck.java