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Migrating templates

Templates written for earlier versions of mapbuilder keep working. This page shows how to move them to the Feature API and what changes in the output.

Renamed filters

Some Feature API filters had different names during development. The old names still work, but log a deprecation warning once per run:

Old name New name
geom_simplify feat_simplify
geom_join feat_join
geom_filter_min_area feat_min_area
feat_exclude_property feat_exclude
geom_raw_coords render_coords or render_area

The geom_raw_coords loop is replaced by a single filter:

STAND:EDDN:01
{%- for c in (s['01'] | geom_raw_coords)[0] %}
    {{ c -}}
{% endfor %}

STAND:EDDN:01
{{ s['01'] | render_coords }}

Older filters

Older filter Feature API
simplify feat_simplify
join_segments feat_join
geoms not needed: filters work on features directly
filter_smaller_than feat_min_area (see below)
combine feat_union
to_line render_line
to_poly(name, color) render_area('OTHER:REGION', name, color=color)
to_poly(name, color, fill) render_coordpoly(fill, name, color)
to_coordline render_coordline
to_symbol render_symbol
to_text render_text
to_text_buffer(name, color, True) feat_text_box(text=name) + render_area('OTHER:REGION', color=color)

Differences to be aware of:

  • filter_smaller_than compared the area of the bounding box, so it also kept long lines. feat_min_area uses the real area and always drops lines.
  • to_coordline and to_poly with a fill wrote a single COORDLINE or COORDPOLY after all lines or polygons, so TopSky connected them into one shape. The new renderers end every line and polygon separately. Maps with several lines or polygons per call will look different, as intended.
  • render_line also draws the holes of polygons; to_line did not.
  • render_text and render_symbol clean up labels: they cut off everything from # like to_text did, and also replace colons.

Mixed geometry types

Templates often check the geometry type to choose a renderer. render_grp and render_ts do this for you:

{% for name, geom in data.rivers.items() %}
    {% if geom[0].__class__.__name__ == 'LinearRing' %}
    {{- geom | simplify(default) | to_poly(name, 'River', '100') }}
    {% else %}
    {{- geom | simplify(default) | to_coordline(name) }}
    {% endif %}
{% endfor %}

COLOR:River
{% for name, geom in data.rivers.items() %}
    {{- geom | feat_simplify(default) | render_ts(label=name) }}
{% endfor %}

Data sources

To use the Feature API with full access to properties, use these source types:

Data Older type Feature API type
AIXM 5.1 AerodromeMapping aixm, aixm2 aixm51 (aixm2 data also works)
KML kml kml2
GeoPackage gpkg gpkg (unchanged)

Switch a data source and its templates together

The older filters cannot read data from kml2 sources. When you change a source from kml to kml2, migrate all templates that use it at the same time.

Data from aixm and aixm2 sources is best switched to aixm51. Data is then organised by AIXM feature type, so templates change a little:

Older aixm51
data.x['GuidanceLine'].items() data.x['GuidanceLine'] (a list; the feature ID is feature.id)
data.x['GuidanceLineByDesig']['A'] data.x.group('GuidanceLine', 'designator')['A']
data.x['VerticalStructureByName']['N'] data.x.group('VerticalStructure', 'name')['N']
data.x['RunwayElement']['<uuid>'] data.x.find('<uuid>')
line.type, geom.marking_location line.properties.type, geom.properties.markingLocation

When switching from kml to kml2, the structure of the data stays the same: folders are dicts and placemark names map to lists. Two things change:

  • KML polygons become real polygons, including their holes, instead of plain outlines.
  • A root folder that does not exist stops the build instead of silently using the whole file.