Add screenshot support

Fixes #21

app/views/utils.py

@@ -1,9 +1,31 @@
-from flask import request
+from flask import request, flash
+from app import app
+import random, string, os
+
+def getExtension(filename):
+	return filename.rsplit(".", 1)[1].lower() if "." in filename else None
 
 def isFilenameAllowed(filename, exts):
-	return "." in filename and \
-			filename.rsplit(".", 1)[1].lower() in exts
+	return getExtension(filename) in exts
 
 def shouldReturnJson():
 	return "application/json" in request.accept_mimetypes and \
 			not "text/html" in request.accept_mimetypes
+
+def randomString(n):
+	return ''.join(random.choice(string.ascii_lowercase + \
+			string.ascii_uppercase + string.digits) for _ in range(n))
+
+def doFileUpload(file, allowedExtensions, fileTypeName):
+	if not file or file is None or file.filename == "":
+		flash("No selected file", "error")
+		return None
+
+	ext = getExtension(file.filename)
+	if ext is None or not ext in allowedExtensions:
+		flash("Please upload load " + fileTypeName, "error")
+		return None
+
+	filename = randomString(10) + "." + ext
+	file.save(os.path.join(app.config["UPLOAD_FOLDER"], filename))
+	return "/uploads/" + filename