main.py

import json
import random
import os
import networkx as nx
from io import BytesIO
import base64
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
from flask import Flask, request, render_template, redirect, url_for, session
import graph as g
app = Flask(__name__)

app.secret_key = os.urandom(24)

def getSessionGraph():
    return nx.adjacency_graph(session['graph'])

def setSessionGraph(graph):
    session['graph'] = nx.adjacency_data(graph)

def updateSessionGraph(update = lambda _: None, **kw):
    graph = getSessionGraph()
    update(graph,**kw)
    setSessionGraph(graph)

@app.before_request
def before_request():
    # store empty graph
    if 'graph' not in session:
        session['graph'] = nx.adjacency_data(nx.Graph())

@app.route("/")
def graphInterfaceView():

    graph = getSessionGraph()

    # draw graph
    nx.draw_networkx(graph,font_color='white', pos=nx.circular_layout(graph))

    # base64 encode graph image 
    figfile = BytesIO()
    plt.savefig(figfile, format='png')
    plt.close()

    figfile.seek(0)
    figdata_png = base64.b64encode(figfile.getvalue()).decode('ascii')


    return render_template('index.html',
    image_base64 = figdata_png,
    matrix = str(nx.to_numpy_array(graph)).replace('.',',').replace('\n',','),
    graph = graph,
    data = json.dumps(nx.node_link_data(graph)) ) 

# add and remove node
@app.route("/addnode")
def addnode():

    updateSessionGraph(g.add)

    return redirect(url_for('graphInterfaceView'))

@app.route("/removenode")
def removenode():

    updateSessionGraph(g.remove, node=int(request.args.get('label')))

    return redirect(url_for('graphInterfaceView'))

# add and remove edge 
@app.route("/addedge")
def addedge():
    updateSessionGraph(lambda graph: graph.add_edge(request.args.get('label1'),request.args.get('label2')))

    return redirect(url_for('graphInterfaceView'))

@app.route("/toggleedge")
def toggleedge():
    updateSessionGraph(g.toggle,edge=[int(n) for n in request.args.get('label').split('_')])

    return redirect(url_for('graphInterfaceView'))

# complement graph
@app.route("/complement")
def complementgraph():

    graph = getSessionGraph()
    setSessionGraph(nx.complement(graph))

    return redirect(url_for('graphInterfaceView'))

# complement edges for single node
@app.route("/complementnode")
def complementnode():
    updateSessionGraph(g.complement,node=int(request.args.get('label')))

    return redirect(url_for('graphInterfaceView'))

# clear edges 
@app.route("/clearedges")
def clearedges():

    updateSessionGraph(lambda graph: graph.remove_edges_from(graph.edges()))

    return redirect(url_for('graphInterfaceView'))

# clear graph
@app.route("/clear")
def cleargraph():

    updateSessionGraph(lambda graph: graph.clear())

    return redirect(url_for('graphInterfaceView'))


if __name__ == '__main__':
  app.run()