add babycode preview

app/routes/api.py

@@ -0,0 +1,21 @@
+from flask import Blueprint, request
+from ..auth import is_logged_in, hard_login_required, get_active_user
+from ..lib.babycode import babycode_to_html
+from ..models import APIRateLimits
+
+bp = Blueprint('api', __name__, url_prefix='/api/')
+
+@bp.post('/babycode-preview/')
+@hard_login_required
+def babycode_preview():
+    user = get_active_user()
+    if not APIRateLimits.is_allowed(user.id, 'babycode_preview', 5):
+        return {'error': 'too many requests'}, 429
+    markup = str(request.json.get('markup', ''))
+    if not markup:
+        return {'error': 'markup field missing or invalid type'}, 400
+    banned_tags = request.json.get('banned_tags', [])
+    if not isinstance(banned_tags, list):
+        return {'error': 'banned_tags field is invalid type'}, 400
+    rendered = babycode_to_html(markup, banned_tags).result
+    return {'html': rendered}