add_stock.py

from main import app
from flask import Flask,redirect,url_for,render_template,abort,request,abort,make_response,session,flash
import sqlite3
from werkzeug.utils import secure_filename
import os

UPLOAD_FOLDER = '/home/codio/workspace/bookshop/static/images'
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER 
ALLOWED_EXTENSIONS = ['png', 'jpg', 'jpeg', 'gif']

@app.route('/stock_level') 
def stock_level(): 
    con = sqlite3.connect("prime.db") 
    con.row_factory = sqlite3.Row 
    cur = con.cursor() 
    cur.execute("SELECT * from stock") 
    rows = cur.fetchall(); 
    return render_template("stock_level.html",rows = rows) 

@app.route('/add_stock', methods=['GET', 'POST'])
def add_stock():
    '''this is a page with a form where we can add or update a book in our stock'''
    if request.method == 'POST':
        if request.form['Submit'] == 'SUBMIT':
            file = request.files["file"] #here is the code that let me upload an image into files https://stackoverflow.com/questions/19898283/folder-and-files-upload-with-flask
            if file: # if the user had given us a file
                if allowed_extension(file.filename): # we check if it has one of the allowed extensions
                    # code for removing non ascii characters https://www.kite.com/python/answers/how-to-remove-non-ascii-characters-in-python
                    filename = secure_filename(file.filename) #we check if a filename is secure
                    encoded_filename = filename.encode("ascii", "ignore") # we replace all of the non-ascii characters with ascii ones by encoding a string
                    decoded_filename = encoded_filename.decode() #and later decode it
                    filename = decoded_filename
                    filename = filename.replace(" ","_") #in the name of the file we replace spaces with underscore
                    file.save(os.path.join(app.config['UPLOAD_FOLDER'],filename)) # we save it to our folder for images
                    con = sqlite3.connect('prime.db')
                    con.row_factory = lambda cursor, row: row[0]
                    cur = con.cursor()
                    cur.execute("SELECT ISBN FROM stock WHERE ISBN=?",(request.form['ISBN'],)) #we check if there is already an entry in our db with the same isbn13 number to know if we have to add an entry or update one
                    row = cur.fetchall()
                    if len(row) != 0: #if this is true it means that the fetchall function did found a record with same isbn13 number, and will replace the current record with the new one
                        cur.execute("DELETE FROM stock WHERE ISBN=?",(request.form['ISBN'],)) # it updates an entry by deleting the older one
                    # we add values that we provided in a form into our database 
                    cur.execute("INSERT INTO stock VALUES(?,?,?,?,?,?,?,?,?)",(request.form['name'],request.form['author'],request.form['date'],request.form['ISBN'],request.form['description'],filename,request.form['tradep'],request.form['retailp'],request.form['quantity'])) 
                    con.commit()
                    con.close()
                    return redirect(url_for('stock_level'))
        elif request.form['Submit'] == 'GO BACK':
            return redirect(url_for('stock_levels'))

    else:
        return render_template('add_stock.html')
    
def allowed_extension(filename):
    '''the code below checks if file extension is valid -- based on https://flask.palletsprojects.com/en/2.0.x/patterns/fileuploads/'''
    if '.' not in filename: #if there is no dot in our filename
        return False
    if filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS: #if text after the dot is in ALLOWED_EXTENSIONS
        return True
    return False