Inject API key via env variable

Author: chabb

components.md

@@ -26,7 +26,7 @@ PeriodicContext is a top-level that provides a model for the periodic table that
 PeriodicFilter allows you to use filter some elements on table, by groups/periods/properties.
 It updates the PeriodicContext, which in turn is mirrored on the table.
 ```
-//TODO
+//TODO example file
 ```
 
 #3D Scene
@@ -52,7 +52,7 @@ The JSON of the object will be passed as an argument
 
 ## CameraContext
 
-Camera context allows you to wire the camera of multiple SimpleScenes together.
+Camera context allows you to wire the camera of multiple SimpleScenes together. See `scene_usage.py`
 
 ```
 dash_mp_components.CameraContext(children=[
@@ -87,12 +87,15 @@ dash_mp_components.CameraContext(children=[
 
 ## SearchGrid
 
-This is the whole search interface, wrapped in a React component. Everything happens in the frontend.
+This is the whole search interface, wrapped in a React component. From a dash point of view, this
+component is opaque. Everything happens in the frontend.
 
-## MatSearchGrid / MatPrintViewContext / MAtMaterialsTable
+## MatSearchGrid / MatPrintViewContext / MatMaterialsTable
 
 This is the same interface. The search funnel and the result table are decoupled. The REST call
-happens in dash. See usage.py for more details
+happens in dash. See `usage.py`. The whole search is implemented there
+
+See `search_usage.py` for a very simple example of a card
 
 ```
 dash_mp_components.MatPrintViewContext(children=[

usage.py

@@ -7,6 +7,13 @@
 import functools
 from dash.exceptions import PreventUpdate
 from pymatgen import MPRester
+import os
+
+try:
+    os.environ["MP_API_KEY"]
+except KeyError:
+    print("Please set the environment variable MP_API_KEY")
+    sys.exit(1)
 
 app = dash.Dash(__name__)
 
@@ -99,7 +106,7 @@ def display_output2(c):
     ]
 
     # This should be setted as an env variable instead
-    with MPRester("fJcpJy6hRNF3DzBo") as m:
+    with MPRester(os.environ["MP_API_KEY"]) as m:
         q = m.query(criteria=query, properties=properties)
 
     #print('RESULT', len(q))