correct sameAs syntax in compound cards

FIX #250

ippisite/ippidb/models.py

@@ -1150,6 +1150,21 @@ class Compound(AutoFillableModel):
             else None
         )
 
+    @property
+    def sameas_urls(self):
+        urls = []
+        if self.pubchem_id:
+            urls.append(self.pubchem_url)
+        if self.chembl_id:
+            urls.append(self.chembl_url)
+        if self.chemspider_id:
+            urls.append(self.chemspider_url)
+        if self.ligand_id:
+            urls.append(self.pdbligand_url)
+        if self.drugbank_id:
+            urls.append(self.drugbank_url)
+        return urls
+
     def clean(self):
         """
         Perform additional checks:

ippisite/ippidb/templates/compound_card.html

@@ -572,20 +572,8 @@
 "smiles": [
   "{{ compound.canonical_smile }}"
 ],
-{% if compound.pubchem_id %}
-"sameAs": "{{ compound.pubchem_url }}",
-{% endif %}
-{% if compound.chembl_id %}
-"sameAs": "{{ compound.chembl_url }}",
-{% endif %}
-{% if compound.chemspider_id %}
-"sameAs": "{{ compound.chemspider_url }}",
-{% endif %}
-{% if compound.ligand_id %}
-"sameAs": "{{ compound.pdbligand_url }}",
-{% endif %}
-{% if compound.drugbank_id %}
-"sameAs": "{{ compound.drugbank_url }}",
+{% if compound.sameas_urls %}
+"sameAs": {{ compound.sameas_urls|safe }},
 {% endif %}
 "@context": "http://schema.org"
 }