central word is now green to distinguish it from the others, also fixed some...

central word is now green to distinguish it from the others, also fixed some issues related to adding and removing words

dash_app/app.py

@@ -82,10 +82,12 @@ def graph_elements_callback(add_button_ts, remove_button_ts, submit_button_ts, g
 
     if remove_button_ts > add_button_ts:
         if graph_selected is not None:
-            graph.remove_node(graph_selected['label'])
+            selected_word = graph_selected['label']
+            if selected_word in graph.get_all_words() and selected_word != graph.get_base_word():
+                graph.remove_node(graph_selected['label'])
 
     if add_button_ts > remove_button_ts:
-        if add_word is not None and add_word != '':
+        if add_word is not None and add_word != '' and add_word not in graph.get_all_words():
             graph.add_node(add_word)
             graph.add_edge(graph.get_base_word(), add_word)
 

dash_app/graph.py

@@ -12,6 +12,10 @@ class Graph:
     def get_base_word(self):
         return self.associated_words.get_base_word()
 
+    def get_all_words(self):
+        all_words = [node_dict['data']['label'] for node_dict in self.nodes]
+        return all_words
+
     def clear_graph_elements(self):
         self.nodes = []
         self.edges = []
@@ -24,7 +28,7 @@ class Graph:
         base_word = self.associated_words.get_base_word()
         associated_words = self.associated_words.get_associated_words()
         self.clear_graph_elements()
-        self.add_node(base_word)
+        self.add_node(base_word, is_base_node=1)
         self.add_nodes(associated_words)
         self.add_edges(base_word, associated_words)
 
@@ -32,8 +36,11 @@ class Graph:
         for node in nodes:
             self.add_node(node)
 
-    def add_node(self, node):
-        node_dict = {'data': {'id': node, 'label': node}}
+    def add_node(self, node, is_base_node=0):
+        node_dict = {'data': {'id': node, 'label': node, 'is_base_node': is_base_node}}
+        if is_base_node:
+            node_dict['selectable'] = False
+            node_dict['grabbable'] = False
         if node_dict not in self.nodes:
             self.nodes.append(node_dict)
 
@@ -79,4 +86,19 @@ class Graph:
                               elements=elements,
                               userZoomingEnabled=False,
                               userPanningEnabled=False,
+                              stylesheet=[
+                                  {
+                                      'selector': '[is_base_node > 0.5]',
+                                      'style': {
+                                          'label': 'data(label)',
+                                          'background-color': 'green'
+                                      }
+                                  },
+                                  {
+                                      'selector': '[is_base_node < 0.5]',
+                                      'style': {
+                                          'label': 'data(label)',
+                                      }
+                                  }
+                              ]
                               )