CategoryOverpass: get minZoom from query (if object)

README.md

@@ -62,7 +62,6 @@ File: foo.json
         "14": "(node[highway~'^(motorway_junction|mini_roundabout|crossing)$'];way[highway~'^(motorway|trunk|primary)$'];)",
         "16": "(node[highway];way[highway];)"
     }
-    "minZoom": 12,
     "feature": {
         "style": {
             "color": "{% if tags.highway == 'motorway' %}#ff0000{% elseif tags.highway == 'trunk' %}#ff7f00{% elseif tags.highway == 'primary' %}#ffff00{% else %}#0000ff{% endif %}"
@@ -82,7 +81,7 @@ This will define a category with the id 'foo' (from the file name). It will show
 
 The following values are possible for categories (the only mandatory value is query):
 * query: either a string or an object of strings with the minimal zoom level as index. Give the Overpass API queries without the header (e.g. `[out:json]` or bounding box) and footer (e.g. `out meta geom` or so).
-* minZoom: Show layer only from the given zoom level (default: 14).
+* minZoom: Show layer only from the given zoom level (default: 14). If `query` is an object and `minZoom` is not set, the lowest zoom level of a query will be used.
 * maxZoom: Show layer only up to the given zoom level (default: no limit).
 * feature: an object describing how the feature will be formated resp. styled.
   * style: a Leaflet style.

src/CategoryOverpass.js

@@ -3,7 +3,6 @@ var OverpassLayer = require('overpass-layer')
 var OverpassLayerList = require('overpass-layer').List
 var CategoryBase = require('./CategoryBase')
 var defaultValues = {
-  minZoom: 14,
   feature: {
     title: "{{ localizedTag(tags, 'name') |default(localizedTag(tags, 'operator')) | default(localizedTag(tags, 'ref')) | default(trans('unnamed')) }}",
     markerSign: "",
@@ -46,6 +45,15 @@ function CategoryOverpass (id, data) {
     }
   }
 
+  // get minZoom
+  if ('minZoom' in data) {
+    // has minZoom
+  } else if (typeof data.query === 'object') {
+    data.minZoom = Object.keys(data.query)[0]
+  } else {
+    data.minZoom = 14
+  }
+
   data.feature.appUrl = '#' + this.id + '/{{ id }}'
   data.feature.body = (typeof data.feature.body === 'string' ? data.feature.body : '') + '<a class="showDetails" href="#' + this.id + '/{{ id }}/details">show details</a>'