Canvas Template example in docs (#17)

Added and example of creating a canvas from a canvas template
Added an additional sample file

Signed-off-by: apetrynet <flehnerheener@gmail.com>

docs/getting_started.md

@@ -11,10 +11,10 @@ pip install pyfdl
 
 ```python
 import pyfdl
-from pyfdl import FDL, Canvas, FramingIntent, DimensionsInt, DimensionsFloat, Point
+from pyfdl import Canvas, FramingIntent, DimensionsInt, DimensionsFloat, Point
 from io import StringIO
 
-fdl = FDL()
+fdl = pyfdl.FDL()
 
 # Applying defaults will provide you with a valid staring point 
 fdl.apply_defaults()
@@ -54,3 +54,31 @@ canvas.place_framing_intent(framing_intent=framing_intent)
 with StringIO() as f:
     pyfdl.dump(fdl, f, validate=True)
 ```
+
+## Create a Canvas from a Canvas Template
+```python
+import pyfdl
+from io import StringIO
+from pathlib import Path
+
+fdl_file = Path('tests/sample_data/Scenario-9__OriginalFDL_UsedToMakePlate.fdl')
+with fdl_file.open('r') as f:
+    fdl = pyfdl.load(f)
+
+# Select the first canvas in the first context
+source_canvas = fdl.contexts[0].canvases[0]
+
+# Select the first canvas template
+canvas_template = fdl.canvas_templates[0]
+
+# We know we want to use the first framing decision of the source canvas, so we pass 0
+# You may also pass the actual `FramingDecision` source_canvas.framing_decisions[0]
+new_canvas = pyfdl.Canvas.from_canvas_template(canvas_template, source_canvas, 0)
+
+# Place the new canvas along side the source 
+fdl.contexts[0].canvases.add_item(new_canvas)
+
+# Validate and "save"
+with StringIO() as f:
+    pyfdl.dump(fdl, f, validate=True)
+```

src/pyfdl/canvas.py

@@ -101,9 +101,9 @@ def from_canvas_template(
         based on a [CanvasTemplate](canvas_template.md#Canvas Template)
 
         Args:
-            canvas_template:
-            source_canvas:
-            source_framing_decision:
+            canvas_template: describing how to handle incoming `Canvas` and `FramingDecision`
+            source_canvas: to use as base for new canvas
+            source_framing_decision: either a `FramingDecision` from the source canvas or the index (`int`) of one.
 
         Returns:
             canvas: based on the provided canvas template and sources
@@ -114,7 +114,7 @@ def from_canvas_template(
 
         canvas = Canvas(
             label=canvas_template.label,
-            _id=Base.generate_uuid().strip('-'),
+            _id=Base.generate_uuid().replace('-', ''),
             source_canvas_id=source_canvas.id,
             anamorphic_squeeze=canvas_template.target_anamorphic_squeeze
         )

tests/sample_data/Scenario-9__OriginalFDL_UsedToMakePlate.fdl

@@ -0,0 +1,50 @@
+{
+  "uuid": "6FBE1EBC-50A0-4201-90E0-76C98DFFD04C",
+  "version": {"major": 0, "minor": 1},
+  "fdl_creator": "ASC FDL Committee",
+  "default_framing_intent": "FDLSMP03",
+  "framing_intents": [{
+      "label": "1.78-1 Framing",
+      "id": "FDLSMP03",
+      "aspect_ratio": {"width": 16, "height": 9},
+      "protection": 0.088
+    }
+  ],
+  "contexts": [{
+    "label": "PanavisionDXL2",
+    "context_creator": "ASC FDL Committee",
+    "canvases": [{
+      "label": "Open Gate RAW",
+      "id": "20220310",
+      "source_canvas_id": "20220310",
+      "dimensions": {"width": 5184, "height": 4320},
+      "effective_dimensions": {"width": 5184, "height": 4320},
+      "effective_anchor_point": {"x": 0, "y": 0},
+      "photosite_dimensions": {"width": 5184, "height": 4320},
+      "physical_dimensions": {"width": 25.92, "height": 21.60},
+      "anamorphic_squeeze": 1.30,
+      "framing_decisions": [{
+          "label": "1.78-1 Framing",
+          "id": "20220310-FDLSMP03",
+          "framing_intent_id": "FDLSMP03",
+          "dimensions": {"width": 4728, "height": 3456},
+          "anchor_point": {"x": 228, "y": 432},
+          "protection_dimensions": {"width": 5184, "height": 3790},
+          "protection_anchor_point": {"x": 0, "y": 265}
+        }
+      ]
+    }]
+  }],
+  "canvas_templates": [{
+      "label": "VFX Pull",
+      "id": "VX220310",
+      "target_dimensions": {"width": 4096, "height": 2304},
+      "target_anamorphic_squeeze": 1.00,
+      "fit_source": "framing_decision.dimensions",
+      "fit_method": "width",
+      "alignment_method_vertical": "center",
+      "alignment_method_horizontal": "center",
+      "preserve_from_source_canvas": "canvas.dimensions",
+      "round": {"even": "even", "mode": "up"}
+  }]
+}