Nicegui widgets/Tutorial

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Prerequisites

Before starting the tutorial, it's important to ensure the following prerequisites are met:

These prerequisites are essential for effectively following the tutorial and understanding the implementation of the ConferenceCorpus project.


Example Usecase

This tutorial uses the ConferenceCorpus as it's usecase. As part of my research for the ConfIDent Project i am gathering metadata for scientific events from different datasources. There has been a lack of a proper frontend for the past few years although there have been several attempts to create a webserver and RESTFul services e.g. with

As of 2023-11 the project is now migrated to nicegui using the nicegui widgets (demo)

Setting up the project

The project is on github see ConferenceCorpus

README

A GitHub README is a document that introduces and explains a project hosted on GitHub, providing essential information such as its purpose, how to install and use it, and its features. It is important because it serves as the first point of contact for anyone encountering the project, helping them understand what the project is about and how to engage with it.

The README consists of

  • header
  • badges
  • link to demo
  • example API calls
  • links to documentation
  • authors list

README screenshot as of start of migration

CcReadme2023-11-18.jpg

License

The LICENSE file in a software project specifies the legal terms under which the software can be used, modified, and shared, defining the rights and restrictions for users and developers. Using the Apache License is a good choice for many projects because it is a permissive open-source license that allows for broad freedom in use and distribution, while also providing legal protection against patent claims and requiring preservation of copyright notices.

LICENSE

pyproject.toml

pyproject.toml

pyproject.toml is a configuration file used in Python projects to define project metadata, dependencies, and build system requirements, providing a consistent and standardized way to configure Python projects. For more information, see pyproject.toml documentation.

Hatchling is a popular choice for a build system because it offers a modern, fast, and straightforward approach to building and managing Python projects, aligning well with the standardized structure provided by pyproject.toml. Learn more about Hatchling at Hatchling on GitHub.

This pyproject.toml file configures the Python project 'ConferenceCorpus', an API for accessing academic events and event series from different sources.

Build System

The [build-system] section defines the build requirements and backend. It specifies the use of 'hatchling' as the build backend:

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

Hatchling is a modern build backend for Python projects, aligning with PEP 517.

Project Metadata

Under the [project] section, several key details about the project are listed:

[project]
name = "ConferenceCorpus"
description = "python api providing access to academic events and event series from different sources"
home-page = "http://wiki.bitplan.com/index.php/ConferenceCorpus"
readme = "README.md"
license = {text = "Apache-2.0"}
authors = [{name = "Wolfgang Fahl", email = "wf@WolfgangFahl.com"}]
maintainers = [{name = "Wolfgang Fahl", email = "wf@WolfgangFahl.com"}]
requires-python = ">=3.9"
classifiers = ['Programming Language :: Python', ...]
dynamic = ["version"]

This section sets the project's name, description, homepage, README, license, authors, maintainers, required Python version, classifiers, and dynamic versioning.

Dependencies

The dependencies section lists the required external libraries for the project to function:

dependencies = [
    "pylodstorage>=0.4.9",
    ...
]

These dependencies ensure that the necessary packages are installed for the project.

Project Scripts

The [project.scripts] section defines executable commands for various functionalities, with a focus on the `ccServer` script for starting the web server:

[project.scripts]
ccServer = "corpus.web.cc_cmd:main"
...

Understanding the ccServer Script

  • Command: ccServer is the command that users will run in the terminal.
  • Function: The value "corpus.web.cc_cmd:main" specifies the Python function that gets executed when `ccServer` is invoked.
    • Package and Module: The first part, corpus.web.cc_cmd, is the Python package and module where the function resides.
    • Function Name: The second part, main, is the name of the function within that module.

Usage

- To start the webserver, a user would execute the following command in the terminal:

 $ ccServer

- This command calls the `main` function from the `cc_cmd.py` file located in the `corpus.web` package, effectively initiating the web server for the ConferenceCorpus project.

Project URLs

The [project.urls] section provides links to the project's home, source, and documentation:

[project.urls]
Home = "http://wiki.bitplan.com/index.php/ConferenceCorpus"
Source = "https://github.com/WolfgangFahl/ConferenceCorpus"
Documentation = "https://github.com/WolfgangFahl/ConferenceCorpus/issues"

These URLs direct users to relevant resources for the project.

Command line

Thanks to niceguiwidget's WebserverCmd base class a command line startup python script only needs a few lines:

'''
Created on 2023-09-10

@author: wf
'''
import sys
from ngwidgets.cmd import WebserverCmd
from corpus.web.cc_webserver import ConferenceCorpusWebserver
class ConferenceCorpusCmd(WebserverCmd):
    """
    command line handling for Conference Corpus Webserver
    """
    
def main(argv:list=None):
    """
    main call
    """
    cmd=ConferenceCorpusCmd(config=ConferenceCorpusWebserver.get_config(),webserver_cls=ConferenceCorpusWebserver)
    exit_code=cmd.cmd_main(argv)
    return exit_code
        
DEBUG = 0
if __name__ == "__main__":
    if DEBUG:
        sys.argv.append("-d")
    sys.exit(main())

Usage

ccServer -h
usage: ccServer [-h] [-a] [-c] [-d] [--debugServer DEBUGSERVER]
                [--debugPort DEBUGPORT] [--debugRemotePath DEBUGREMOTEPATH]
                [--debugLocalPath DEBUGLOCALPATH] [-l] [-i INPUT] [-rol]
                [--host HOST] [--port PORT] [-s] [-V]

Conference Corpus Volume browser

options:
  -h, --help            show this help message and exit
  -a, --about           show about info [default: False]
  -c, --client          start client [default: False]
  -d, --debug           show debug info [default: False]
  --debugServer DEBUGSERVER
                        remote debug Server
  --debugPort DEBUGPORT
                        remote debug Port
  --debugRemotePath DEBUGREMOTEPATH
                        remote debug Server path mapping - remotePath - path
                        on debug server
  --debugLocalPath DEBUGLOCALPATH
                        remote debug Server path mapping - localPath - path on
                        machine where python runs
  -l, --local           run with local file system access [default: False]
  -i INPUT, --input INPUT
                        input file
  -rol, --render_on_load
                        render on load [default: False]
  --host HOST           the host to serve / listen from [default: localhost]
  --port PORT           the port to serve from [default: 5005]
  -s, --serve           start webserver [default: False]
  -V, --version         show program's version number and exit

Installation

We use pip to install. There is also a bash script in scripts/install (which we'll later user in our github CI)

pip install .

Webserver

Minimum Webserver code

Thanks to niceguiwidget's InputWebserver base class a the cc_webserver module only needs a few lines:

"""
Created on 2023-11-18

@author: wf
"""
from ngwidgets.input_webserver import InputWebserver
from ngwidgets.webserver import WebserverConfig
from corpus.version import Version

class ConferenceCorpusWebserver(InputWebserver):
    """
    Webserver for the Conference Corpus
    """
    
    @classmethod
    def get_config(cls) -> WebserverConfig:
        """
        get the configuration for this Webserver
        """
        copy_right = "(c)2020-2023 Wolfgang Fahl"
        config = WebserverConfig(
            copy_right=copy_right, version=Version(), default_port=5005
        )
        return config
    
    def __init__(self):
        """Constructor"""
        InputWebserver.__init__(self, config=ConferenceCorpusWebserver.get_config())

Starting the webserver from the commandline

ccServer -s -c

will start your webserver and open a browser to access it. The default port is 5005 and therefore the link http://localhost:5005 should allow you test the results.

ccServer -s --host 0.0.0.0 port=80

Will make the server the default webserver on your intranet and http://<your-hostname> will allow you to access your server.

Default layout and menu

The default menu looks like this: Ngwidgets default header.jpg

Apache Server installation

To serve from an Apache Server we need to start the service (e.g. on reboot) and make it available via an apache configuration. We also have to make sure the service is available on the internet and findable by the DNS system.

DNS entry

My services are hoste via hosteurope where i can access my DNS entries via its KIS system

By adding cc2 as a cname for on.bitplan.com http://cc2.bitplan.com now points to http://on.bitplan.com Kisscreenshot2023-11-18.jpg

apache configuration

Our server is an Ubuntu 22.04 LTS machine. The configuration is at /etc/apache2/sites-available/conferencecorpus.conf

<VirtualHost *:80 >
	# The ServerName directive sets the request scheme, hostname and port that
	# the server uses to identify itself. This is used when creating
	# redirection URLs. In the context of virtual hosts, the ServerName
	# specifies what hostname must appear in the request's Host: header to
	# match this virtual host. For the default virtual host (this file) this
	# value is not decisive as it is used as a last resort host regardless.
	# However, you must set it for any further virtual host explicitly.
	ServerName cc2.bitplan.com

	ServerAdmin webmaster@bitplan.com
	#DocumentRoot /var/www/html

	# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
	# error, crit, alert, emerg.
	# It is also possible to configure the loglevel for particular
	# modules, e.g.
	#LogLevel info ssl:warn

	ErrorLog ${APACHE_LOG_DIR}/cc_error.log
	CustomLog ${APACHE_LOG_DIR}/cc.log combined

	# For most configuration files from conf-available/, which are
	# enabled or disabled at a global level, it is possible to
	# include a line for only one particular virtual host. For example the
	# following line enables the CGI configuration for this host only
	# after it has been globally disabled with "a2disconf".
	#Include conf-available/serve-cgi-bin.conf
        RewriteEngine On
        RewriteCond %{HTTP:Upgrade} =websocket [NC]
        RewriteRule /(.*)           ws://localhost:5005/$1 [P,L]
        RewriteCond %{HTTP:Upgrade} !=websocket [NC]
        RewriteRule /(.*)           http://localhost:5005/$1 [P,L]

	# make local Conference Corpus webserver available 
	ProxyPassReverse / http://localhost:5005/
</VirtualHost>