Display latex errors as applicable

flaskr/templates/writing.html

@@ -61,6 +61,13 @@
     {{ render_field(form.body, 'class=bigtext') }}
     {{ render_field(form.closingtext) }}
   </dl>
+  {% if err %}
+    <p>
+    {% for error in err %}
+      {{ error }}<br>
+    {% endfor %}
+    </p>
+  {% endif %}
   <p><input type=submit value="Submit"></p>
 </form>
 </body>

latty.py

@@ -47,20 +47,25 @@ class CLData():
         f.write(open(proj_dir + "/writing_templates/base.tex", "r").read())
         f.close()
 
-        com = "pdflatex -halt-on-error -jobname=outputs/" + unique_id + " " + unique_file
+        output_arg="-jobname=outputs/" + unique_id + " " + unique_file
+        com = "pdflatex -halt-on-error " + output_arg
         print("COM: '" + com + "'")
-        try:
-            subprocess.check_call(['bash', '-c', com])
+        result = subprocess.run(['bash', '-c', com], stdout=subprocess.PIPE, text=True)
+
+        if result.returncode == 0:
             threading.Timer(60 * 30, cleanup, [output_dir + unique_id]).start()
 
-            return send_from_directory(
+            return (send_from_directory(
                 output_dir,
                 unique_id + ".pdf",
                 attachment_filename=self.username.replace(" ", "") + "_CoverLetter.pdf",
                 as_attachment=True
-            )
-        except subprocess.CalledProcessError:
-            return None
+            ), None)
+        else:
+            errors = result.stdout.split("\n")
+            del errors[:13]
+            del errors[-2:]
+            return (None, errors)
 
 def cleanup(unique):
     print(unique)

writing.py

@@ -61,11 +61,12 @@ def index():
             body=form.body.data,
         )
 
-        resp = data.generate_pdf()
+        (resp, err) = data.generate_pdf()
         # Save entered data as cookies on user's machine
-        if not resp:
+        if err:
             resp = make_response(render_template('writing.html',
                 form=form,
+                err=err,
             ))
         for pair in data.get_pairs():
             resp.set_cookie(pair[0], urllib.parse.quote(pair[1]))