app.py

from flask import Flask, render_template, session, request
from guilayer.artistform import ArtistForm
from flask_bootstrap import Bootstrap
from applayer.artistlist import ArtistList
from bokeh.resources import INLINE
from applayer.artistgraph import ArtistGraph
from guilayer.render import render_graph


app = Flask(__name__)
app.config['SECRET_KEY'] = 'jerrygthesupremeleader'
bootstrap = Bootstrap(app)


@app.route('/', methods=['GET', 'POST'])
@app.route('/index.html', methods=['GET', 'POST'])
def main_page():
    """
    Sets up the page used to display the application; Uses a single form
    in a two-div structured page. The page is styled minimally using bootstrap
    :return: rendered page
    """
    # grab the static resources
    js_resources = INLINE.render_js()
    css_resources = INLINE.render_css()

    # render graph
    the_graph, script, div = None, None, None
    debug = False  # False displays graph

    if request.method == 'GET':
        session.clear()
    session['select'] = None
    if 'expansion_select' in session:
        choices = session['expansion_select']
    else:
        choices = []
    form = ArtistForm(choices=choices)

    artist_list = None

    if form.validate_on_submit():
        session['select'] = form.select.data
        # Use the selected data to build a graph by getting the list
        # of objects and passing them to an ArtistGraph object
        artist_list = ArtistList(session['select'])
        ag = ArtistGraph(artist_list, int(form.depth.data))
        if len(form.expanse_select.data) >= 1:
            ag.expand_graph(int(form.expanse_select.data[0]))
            ag = ArtistGraph(artist_list, int(form.depth.data) + 1)
        expansion_list: ArtistList = ag.get_expansion_list()
        session['expansion_select'] = expansion_list
        choices = expansion_list
        ag.compute_degree_centrality()
        ag.compute_closeness_centrality()
        ag.compute_betweenness_centrality()
        script, div = render_graph(ag.graph)
        form = ArtistForm(choices=choices)

    html = render_template('index.html', title='Home', formtitle='Artist Social Network',
                           form=form, plot_script=script, debug=debug,
                           plot_div=div, js_resources=js_resources, css_resources=css_resources)
    return html


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