app\main\views(4).py

#...
from flask import current_app, render_template, flash, redirect, url_for
from .forms import EditProfileForm, EditProfileAdminForm, CollectionForm
from .. import db
from ..models import User, Role, Collection, Permission
import stream
#...

@main.route('/collection/<int:id>', methods=['GET'])
def get_collection(id):
    collection = Collection.query.get_or_404(id)
    return render_template('collection.html', collection=collection)


@main.route('/new-collection/', methods=['GET', 'POST'])
@login_required
def new_collection():
    form = CollectionForm()
    if current_user.can(Permission.WRITE) and form.validate_on_submit():
        collection = Collection(name=form.name.data,
                                description=form.description.data,
                                author=current_user._get_current_object())
        db.session.add(collection)
        if collection.add_to_stream():
            db.session.commit()
            flash("You have created a new Collection!")
            return redirect(url_for('.get_collection', id=collection.id))
        else:
            db.session.delete(collection)
            db.session.commit()
            flash("An error occurred, please try again")
            return redirect(url_for('.new_collection'))
    return render_template('new_collection.html', form=form)