feat: support layers in the draw.io

multicloud_diagrams/__init__.py

@@ -43,11 +43,18 @@ def __init__(self, debug_mode=False):
                                             guides="1", tooltips="1", connect="1", arrows="1", fold="1", page="1",
                                             pageScale="1", pageWidth="850", pageHeight="1100", math="0", shadow="0")
         self.root = et.SubElement(self.mx_graph_model, 'root')
+        self.layers = {}
         self.mx_cell_id_0 = et.SubElement(self.root, 'mxCell', id="0")
-        self.mx_cell_id_1 = et.SubElement(self.root, 'mxCell', id="1", parent="0")
-
+        self.add_layer()
         self.debug_mode = debug_mode
 
+    def add_layer(self, layer_name: str = ''):
+        self.layers[self.get_current_layer_count() + 1] = layer_name
+        self.mx_cell_id_0 = et.SubElement(self.root, 'mxCell', id=f"{self.get_current_layer_count()}", parent="0")
+
+    def get_current_layer_count(self):
+        return len(self.layers)
+
     prev_coords = {}
 
     supported_vertex = {}

tests/test_layers.py

@@ -0,0 +1,60 @@
+from multicloud_diagrams import MultiCloudDiagrams
+import xml.etree.ElementTree as et
+
+from utils.utils import TestUtilities
+
+
+class TestMultiCloudDiagramsLayers(TestUtilities):
+
+    def test_default_layer(self):
+        # given-when
+        mcd = MultiCloudDiagrams(debug_mode=True)
+
+        # then
+        tree = et.ElementTree(mcd.mxfile)
+        self.verify_mxfile_default(et.ElementTree(tree))
+
+        mx_cells = tree.findall("./*/*/*/")
+
+        self.verify_layers(mx_cells, 1, mcd)
+
+    def test_add_2_layers(self):
+        # given
+        mcd = MultiCloudDiagrams(debug_mode=True)
+
+        # when
+        mcd.add_layer('L2')
+
+        # then
+        tree = et.ElementTree(mcd.mxfile)
+        self.verify_mxfile_default(et.ElementTree(tree))
+
+        mx_cells = tree.findall("./*/*/*/")
+
+        self.verify_layers(mx_cells, 2, mcd)
+
+    def test_add_3_layers(self):
+        # given
+        mcd = MultiCloudDiagrams(debug_mode=True)
+
+        # when
+        mcd.add_layer('L2')
+        mcd.add_layer('L3')
+
+        # then
+        tree = et.ElementTree(mcd.mxfile)
+        self.verify_mxfile_default(et.ElementTree(tree))
+
+        mx_cells = tree.findall("./*/*/*/")
+
+        self.verify_layers(mx_cells, 3, mcd)
+
+    def verify_layers(self, mx_cells, layers_count, mcd):
+        self.assertEqual(layers_count + 1, len(mx_cells))
+        self.verify_mx_cell(mx_cells[0], expected={'id': '0'})
+        expected_layer = {1: ''}
+        for id in range(layers_count):
+            self.verify_mx_cell(mx_cells[id + 1], expected={'id': f'{id + 1}', 'parent': '0'})
+            if id > 0:
+                expected_layer[id + 1] = f'L{id + 1}'
+        self.assertEqual(expected_layer, mcd.layers)