Add base code for realtime listener snippets

Frank Natividad · Frank Natividad · commit 6a4331ed596f · 2018-11-29T22:48:06.000-08:00
diff --git a/firestore/cloud-client/snippets.py b/firestore/cloud-client/snippets.py
@@ -603,6 +603,112 @@ def cursor_paginate():
     return next_query
 
 
+def listen_document():
+    db = firestore.Client()
+    # [START listen_document]
+
+    # Create a callback on_snapshot function to capture changes
+    def on_snapshot(doc_snapshot):
+        print(u'Received doc snapshot: {}'.format(doc_snapshot.to_dict()))
+
+    doc_ref = db.collection(u'cities').document(u'SF')
+
+    # Watch the document
+    doc_watch = doc_ref.on_snapshot(on_snapshot)
+    # [END listen_document]
+
+    print(u'Creating document')
+    data = {
+        u'name': u'San Francisco',
+        u'state': u'CA',
+        u'country': u'USA',
+        u'capital': False,
+        u'population': 860000
+    }
+    db.collection(u'cities').document(u'SF').set(data)
+
+    # [START detach_listener]
+    # Terminate watch on a document
+    doc_watch.unsubscribe()
+    # [START detach_listener]
+
+
+def listen_multiple():
+    db = firestore.Client()
+    # [START listen_multiple]
+
+    # Create a callback on_snapshot function to capture changes
+    def on_snapshot(col_snapshot):
+        print(u'Callback received query snapshot.')
+        print(u'Current cities in California: ')
+        for doc in col_snapshot.documents:
+            print(u'{} => {}'.format(doc.id))
+
+    col_query = db.collection(u'cities').where(u'state', u'==', u'CA')
+
+    # Watch the collection query
+    query_watch = col_query.on_snapshot(on_snapshot)
+
+    # [END listen_multiple]
+    mtv_document = db.collection(u'cities').document(u'MTV')
+    print(u'Creating document')
+    mtv_document.set({
+        u'name': u'Mountain View',
+        u'state': u'CA',
+        u'country': u'USA',
+        u'capital': False,
+        u'population': 80000
+    })
+
+    print(u'Modifying document')
+    mtv_document.update({
+        u'name': u'Mountain View',
+        u'state': u'CA',
+        u'country': u'USA',
+        u'capital': False,
+        u'population': 90000
+    })
+
+    print(u'Delete document')
+    mtv_document.delete()
+    query_watch.unsubscribe()
+
+
+def listen_for_changes():
+    db = firestore.Client()
+    # [START listen_for_changes]
+
+    # Create a callback on_snapshot function to capture changes
+    def on_snapshot(col_snapshot, changes):
+        print(u'Callback received query snapshot.')
+        print(u'Current cities in California: ')
+        for change in changes:
+            if change.type.name == "ADDED":
+                print(u'New city: {}'.format(change.document.data()))
+            elif change.type.name == "MODIFIED":
+                print(u'Modified city: {}'.format(change.document.data()))
+            elif change.type.name == "REMOVED":
+                print(u'Removed city: {}'.format(change.document.data()))
+
+    col_query = db.collection(u'cities').where(u'state', u'==', u'CA')
+
+    # Watch the collection query
+    query_watch = col_query.on_snapshot(on_snapshot)
+
+    # [END listen_for_changes]
+    print(u'Creating document')
+    data = {
+        u'name': u'San Francisco',
+        u'state': u'CA',
+        u'country': u'USA',
+        u'capital': False,
+        u'population': 860000
+    }
+    db.collection(u'cities').document(u'SF').set(data)
+
+    query_watch.unsubscribe()
+
+
 def cursor_multiple_conditions():
     db = firestore.Client()
     # [START cursor_multiple_conditions]
diff --git a/firestore/cloud-client/snippets_test.py b/firestore/cloud-client/snippets_test.py
@@ -220,5 +220,29 @@ def test_delete_field(db):
     snippets.delete_field()
 
 
+def test_listen_document(capsys):
+    snippets.listen_document()
+    out, _ = capsys.readouterr()
+    assert "SF" in out
+    assert "TOK" in out
+    assert "BJ" in out
+
+
+def test_listen_multiple(capsys):
+    snippets.listen_multiple()
+    out, _ = capsys.readouterr()
+    assert "SF" in out
+    assert "TOK" in out
+    assert "BJ" in out
+
+
+def test_listen_for_changes(capsys):
+    snippets.listen_for_changes()
+    out, _ = capsys.readouterr()
+    assert "SF" in out
+    assert "TOK" in out
+    assert "BJ" in out
+
+
 def test_delete_full_collection():
     snippets.delete_full_collection()
