3.1. Web application setup

3.1.1. Using GwWeb

Before we start coding our own views for our new web application, we need to configure our app to support the basic features for a web application.

Open the file configuration.py and configure it to use the following plugins:

PLUGINS = ["csv_manager_plugin", "GwPluginsInfo", "CsvWatcherDbPlugin", "CsvDocumentPlugin", "GwDocumentsInfo",
           "GwWeb", "GwWebManager", ]

As you can see, we have added GwWeb and GwWebManager.

GwWeb will provide command line commands to start a web server. It also handles the configuration and ramp up of the flask framework in the background.

GwWebManager is not really needed, as it only provides some views to show groundwork internal data like registered commands, signals, plugins, web views and much more. It is very helpful for developers to see the current status of an application without the need of debugging the code for a first overview.

Please also add the following, new configuration parameters to configuration.py:


These parameters are used to configure flask.

FLASK_SERVER_NAME must be set to the domain you will use in your browser to view the web application. This is very important, as flask can handle multiple apps in parallel, which all are registered for different domains (e.g. example.com and my_site.net). Depending on which domain is called, flask looks into its configuration and loads the requested view. So if you use “” and try to open your site with “localhost:5000”, you will get a 404 response for all views. Please note that also the port must be part of FLASK_SERVER_NAME.

FLASK_HOST is the external address to which the server gets bound. Normally “” or “” are working well. If your computer provides several outgoing ethernet interfaces, a specific IP may be needed to bound the server to one interface only.

FLASK_PORT stores the port, which shall be used for connections.

And FLASK_DEBUG starts the flask server in debugging mode. The debugging mode will catch exceptions and presents the traceback as web view. It also restarts the server, if it detects changes on related files. However, it starts the application also twice, in 2 separated processes. Which makes it hard to set breakpoints and debug it inside an IDE.

Now let’s start our new web app and see, if we have configured everything correct by opening the WebManager:

csv_manager server_start flask_debug

Now open the WebManager at

That’s it. Everything should run now as expected. It’s time to take a look into our database via the browser. Go on with Database views made simple.