Merge pull request #31 from ThalesGroup/dev-29

Fix issue 29 (cannot test) and 30

Author: LabordePierre

src/OWS-Tests/OWSTMSTest.class.st

@@ -22,7 +22,16 @@ OWSTMSTest >> testTile [
 	tms url: 'https://tile.openstreetmap.org/{z}/{x}/{y}.png'.
 
 	tile := tms tile: 0 y: 0 z: 0.
-
 	self assert: tile height equals: 256.
 	self assert: tile width equals: 256
 ]
+
+{ #category : #tests }
+OWSTMSTest >> testTileNotExists [
+
+	| tile |
+	tms url: 'https://tile.thisdomaindoesnotexist.org/{z}/{x}/{y}.png'.
+
+	tile := tms tile: 0 y: 0 z: 0.
+	self assert: tile isNil
+]

src/OWS/OWSTMS.class.st

@@ -15,11 +15,15 @@ OWSTMS >> tile: aX y: aY z: aZ [
 	tileUrl := tileUrl copyReplaceAll: '{y}' with: aY printString.
 	tileUrl := tileUrl copyReplaceAll: '{z}' with: aZ printString.
 
-	result := ZnClient new 
+	result := [ ZnClient new 
 		url: tileUrl;
-		get.
+		get ] on: NameLookupFailure do:[ :ex |
+		"Cannot reach the url, curently when there is no network, return nil"
+		nil
+	].
 
-	result isString ifTrue: [ (Error new messageText: result) signal ].
+	result ifNil:[ ^ nil ].
+	result isString ifTrue: [ ^ nil ].
 
 	^ Form fromBinaryStream: result readStream
 ]