Fix subregions search

src/GADM.jl

@@ -85,6 +85,27 @@ function getlayer(data, level)
     throw(ArgumentError("asked for level $(level), valid levels are 0-$(nlayers - 1)"))
 end
 
+"""
+    filterlayer(data, qkeys, qvalues)
+
+Filter layer's rows that satisfies the query params `qkeys` and `qvalues`.
+"""
+function filterlayer(layer, qkeys, qvalues)
+    filtered = []
+    for row in layer
+        matchqueries = true
+        for (qkey, qvalue) in zip(qkeys, qvalues)
+            field = ArchGDAL.getfield(row, qkey)
+            if lowercase(field) ≠ lowercase(qvalue)
+                matchqueries = false
+                break
+            end
+        end
+        matchqueries && push!(filtered, row)
+    end
+    return Tables.columntable(filtered)
+end
+
 """
     get(country, subregions...; depth=0)
 Returns a Tables.jl columntable for the requested region
@@ -108,31 +129,17 @@ data = get("IND", "Uttar Pradesh"; depth=1)
 """
 function get(country, subregions...; depth=0)
     data = getdataset(country)
-    nlayers = ArchGDAL.nlayer(data)
-
-    function filterlayer(layer, key, value, all=false)
-        filtered = []
-        for row in layer
-            index = ArchGDAL.findfieldindex(row, Symbol(key))
-            field = ArchGDAL.getfield(row, index)
-            if all || occursin(lowercase(value), lowercase(field))
-                push!(filtered, row)
-            end
-        end
-        return Tables.columntable(filtered)
-    end
 
     # fetch query params
-    qname = isempty(subregions) ? "" : last(subregions)
-    qlevel = length(subregions)
-    qlevel ≥ nlayers && throw(ArgumentError("more subregions provided than actual"))
-
+    qkeys = ["NAME_$(qlevel)" for qlevel in 1:length(subregions)]
+    qvalues = subregions
+
     # select layer by level
     level = length(subregions) + depth
     slayer = getlayer(data, level)
 
     # filter layer by subregions 
-    slayer = filterlayer(slayer, "NAME_$(qlevel)", qname, iszero(qlevel))
+    slayer = filterlayer(slayer, qkeys, qvalues)
     isempty(slayer) && throw(ArgumentError("could not find required region"))
 
     slayer

test/GADM.jl

@@ -43,7 +43,7 @@ end
     @test GeoInterface.geomtrait(country.geom[1]) isa MultiPolygonTrait
 
     # get country and states
-    country, states = GADM.get("IND";depth=0), GADM.get("IND", depth=1)
+    country, states = GADM.get("IND", depth=0), GADM.get("IND", depth=1)
     @test Tables.istable(country)
     @test Tables.istable(states)
     @test GeoInterface.geomtrait(country.geom[1]) isa MultiPolygonTrait
@@ -72,6 +72,23 @@ end
 
     # throws argument error when the level is deeper than available in dataset
     @test_throws ArgumentError GADM.get("IND", depth=4)
+
+    # subregions tests
+    subregions = GADM.get("SUR", "Para", depth=1)
+    expected = ["Bigi Poika", "Carolina", "Noord", "Oost", "Zuid"]
+    @test issetequal(subregions.NAME_2, expected)
+
+    # subregions with same name
+    suriname = GADM.get("SUR", depth=2)
+    @test count(==("Welgelegen"), suriname.NAME_2) == 2
+
+    coronie = GADM.get("SUR", "Coronie", "Welgelegen")
+    paramaribo = GADM.get("SUR", "Paramaribo", "Welgelegen")
+    @test length(coronie.NAME_1) == length(paramaribo.NAME_1) == 1
+    @test coronie.NAME_1 ≠ paramaribo.NAME_1
+
+    # invalid subregion
+    @test_throws ArgumentError GADM.get("SUR", "a", "Welgelegen")
 end
 
 @testset "basic" begin