Nicer error for empty preview spec submission.

3 files changed, 5 insertions, 2 deletions

diff --git a/libpathod/app.py b/libpathod/app.py
index 17be448d..e93a898f 100644
--- a/libpathod/app.py
+++ b/libpathod/app.py
@@ -82,12 +82,17 @@ def _preview(is_request):
         template = "response_preview.html"
 
     spec = request.args["spec"]
+
     args = dict(
         spec = spec,
         section = "main",
         syntaxerror = None,
         error = None
     )
+    if not spec.strip():
+        args["error"] = "Can't parse an empty spec."
+        return render(template, **args)
+
     try:
         if is_request:
             r = rparse.parse_request(app.config["pathod"].request_settings, spec)
diff --git a/libpathod/templates/request_preview.html b/libpathod/templates/request_preview.html
index fe8a03e9..eaf78898 100644
--- a/libpathod/templates/request_preview.html
+++ b/libpathod/templates/request_preview.html
@@ -7,7 +7,6 @@
     <h2> Error: {{ syntaxerror }} </h2>
     <pre>{{ marked }}</pre>
 {% elif error %}
-    <h2> Error </h2>
     <p style="color: #ff0000">{{ error }}</p>
 {% else %}
     <h2>Spec:</h2>
diff --git a/libpathod/templates/response_preview.html b/libpathod/templates/response_preview.html
index 1b44e480..2e1abcf4 100644
--- a/libpathod/templates/response_preview.html
+++ b/libpathod/templates/response_preview.html
@@ -7,7 +7,6 @@
     <h2> Error: {{ syntaxerror }} </h2>
     <pre>{{ marked }}</pre>
 {% elif error %}
-    <h2> Error </h2>
     <p style="color: #ff0000">{{ error }}</p>
 {% else %}
     <h2>Spec:</h2>