A RECEIPT GENERATOR WEB APP

A web app which generates receipt. Made with the help of Chat-GPT.

Author: parz1val37

app.py

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+from shiny import App, ui, render, reactive
+import pandas as pd
+import datetime
+from reportlab.lib.pagesizes import letter
+from reportlab.platypus import SimpleDocTemplate, Table, TableStyle, Paragraph, Spacer
+from reportlab.lib import colors
+from reportlab.lib.styles import getSampleStyleSheet
+import tempfile, os
+
+# Reactive storage
+items = reactive.Value(pd.DataFrame(columns=["Product_Code", "Qty", "Category", "Price"]))
+edit_index = reactive.Value(None)
+
+app_ui = ui.page_sidebar(
+    ui.sidebar(
+        ui.input_text("code", "Product_Code", ""),
+        ui.input_select(
+            "desc", "Category",
+            {"Shirt": "Shirt", "Pants": "Pants", "T-Shirt": "T-Shirt", "Trouser": "Trouser"},
+        ),
+        ui.input_numeric("qty", "Quantity", 1, min=1),
+        ui.input_numeric("price", "Price", 0.0, min=0.0, step=0.01),
+        ui.input_slider("tax_rate", "Tax (%)", 0, 20, 8, step=1),
+        ui.layout_columns(
+            ui.input_action_button("add", "Add Item", class_="btn btn-primary btn-sm"),
+            ui.input_action_button("update", "Update Item", class_="btn btn-success btn-sm"),
+            ui.input_action_button("clear", "Clear All", class_="btn btn-danger btn-sm"),
+        ),
+        ui.download_button("download_pdf", "Download Receipt (PDF)", class_="btn btn-secondary btn-sm"),
+        open="always",
+    ),
+    ui.layout_columns(
+        ui.card(
+            ui.card_header("Items Added"),
+            ui.output_ui("items_table"),
+        ),
+        ui.card(
+            ui.card_header("Generated Receipt"),
+            ui.output_ui("receipt"),
+        ),
+    ),
+)
+
+def server(input, output, session):
+    # Same Add / Update / Clear / Edit / Delete code as before ----------------
+    @reactive.effect
+    @reactive.event(input.add)
+    def _add():
+        df = items.get().copy()
+        df = pd.concat(
+            [df, pd.DataFrame([{
+                "Product_Code": input.code(),
+                "Qty": input.qty(),
+                "Category": input.desc(),
+                "Price": input.price(),
+            }])],
+            ignore_index=True,
+        )
+        items.set(df)
+
+    @reactive.effect
+    @reactive.event(input.update)
+    def _update():
+        idx = edit_index.get()
+        if idx is not None:
+            df = items.get().copy()
+            if 0 <= idx < len(df):
+                df.loc[idx] = {
+                    "Product_Code": input.code(),
+                    "Qty": input.qty(),
+                    "Category": input.desc(),
+                    "Price": input.price(),
+                }
+                items.set(df)
+                edit_index.set(None)
+
+    @reactive.effect
+    @reactive.event(input.clear)
+    def _clear():
+        items.set(pd.DataFrame(columns=["Product_Code", "Qty", "Category", "Price"]))
+
+    @reactive.effect
+    @reactive.event(input.remove_index)
+    def _remove():
+        idx = int(input.remove_index())
+        df = items.get().copy()
+        if 0 <= idx < len(df):
+            items.set(df.drop(idx).reset_index(drop=True))
+
+    @reactive.effect
+    @reactive.event(input.edit_index)
+    def _edit():
+        idx = int(input.edit_index())
+        df = items.get().copy()
+        if 0 <= idx < len(df):
+            row = df.iloc[idx]
+            session.send_input_message("code", {"value": str(row["Product_Code"])})
+            session.send_input_message("desc", {"value": str(row["Category"])})
+            session.send_input_message("qty", {"value": float(row["Qty"])})
+            session.send_input_message("price", {"value": float(row["Price"])})
+            edit_index.set(idx)
+
+    @output
+    @render.ui
+    def items_table():
+        df = items.get()
+        if df.empty:
+            return ui.p("No items yet.")
+
+        rows_html = []
+        for i, r in df.iterrows():
+            rows_html.append(
+                f"""
+                <tr>
+                  <td style="white-space:nowrap;">
+                    <button class="btn btn-sm btn-warning"
+                      onclick="Shiny.setInputValue('edit_index', {i}, {{priority:'event'}})">✏️ Edit</button>
+                    <button class="btn btn-sm btn-danger"
+                      onclick="Shiny.setInputValue('remove_index', {i}, {{priority:'event'}})">❎ Delete</button>
+                  </td>
+                  <td>{r['Product_Code']}</td>
+                  <td>{r['Qty']}</td>
+                  <td>{r['Category']}</td>
+                  <td>{r['Price']:.2f}</td>
+                </tr>
+                """
+            )
+
+        return ui.HTML(
+            """
+            <table class="table table-sm" style="font-size:13px; border-collapse:collapse;">
+              <thead>
+                <tr><th style="width:140px;">Actions</th><th>Product_Code</th><th>Qty</th><th>Item</th><th>Price</th></tr>
+              </thead>
+              <tbody>
+            """ + "\n".join(rows_html) + """
+              </tbody>
+            </table>
+            """
+        )
+
+    @output
+    @render.ui
+    def receipt():
+        df = items.get()
+        if df.empty:
+            return ui.p("No items yet.")
+
+        subtotal = float((df["Qty"] * df["Price"]).sum())
+        tax_rate = input.tax_rate() / 100.0
+        tax = round(subtotal * tax_rate, 2)
+        total = round(subtotal + tax, 2)
+        now = datetime.datetime.now()
+
+        lines = "".join(
+            f"<tr><td>{row.Product_Code}</td><td>{row.Qty}</td><td>{row.Category}</td><td>{row.Price:.2f}</td></tr>"
+            for row in df.itertuples()
+        )
+
+        return ui.HTML(f"""
+        <div style="border:1px solid #000; padding:10px; width:280px; font-family:monospace; font-size:13px">
+          <h4 style="text-align:center; margin:0;">RECEIPT 🧾</h4>
+          <p style="margin:2px 0;">Nr.: 69 </p>
+          <hr style="margin:4px 0;">
+          <table style="width:100%; font-size:12px; border-collapse:collapse;">
+            <tr><th>Product_Code</th><th>Qty</th><th>Item</th><th>Price</th></tr>
+            {lines}
+          </table>
+          <hr style="margin:4px 0;">
+          <p style="margin:2px 0;">Subtotal: {subtotal:.2f}</p>
+          <p style="margin:2px 0;">Tax ({input.tax_rate()}%): {tax:.2f}</p>
+          <p style="margin:2px 0;"><b>Total: {total:.2f}</b></p>
+          <hr style="margin:4px 0;">
+          <p style="margin:2px 0;">Date: {now.strftime('%d/%m/%Y')}</p>
+          <p style="margin:2px 0;">Time: {now.strftime('%I:%M %p')}</p>
+        </div>
+        """)
+
+    # PDF Download (receipt-style narrow width)
+    @render.download(filename=lambda: f"receipt_{datetime.datetime.now().strftime('%Y%m%d_%H%M%S')}.pdf")
+    def download_pdf():
+        df = items.get()
+        if df.empty:
+            yield b""
+            return
+
+        subtotal = float((df["Qty"] * df["Price"]).sum())
+        tax_rate = input.tax_rate() / 100.0
+        tax = round(subtotal * tax_rate, 2)
+        total = round(subtotal + tax, 2)
+        now = datetime.datetime.now()
+
+        from io import BytesIO
+        buffer = BytesIO()
+
+        # --- custom page size like thermal roll ---
+        RECEIPT_WIDTH = 220  # ~80mm
+        RECEIPT_HEIGHT = 600
+        receipt_page = (RECEIPT_WIDTH, RECEIPT_HEIGHT)
+
+        doc = SimpleDocTemplate(
+            buffer,
+            pagesize=receipt_page,
+            leftMargin=10, rightMargin=10, topMargin=10, bottomMargin=10
+        )
+        styles = getSampleStyleSheet()
+        elements = []
+
+        # ---- Shop name / Header ----
+        elements.append(Paragraph("<b>PARZi GLOBAL</b>", styles["Title"]))
+        elements.append(Paragraph(f"Nr.: {now.strftime('%Y%m%d%H%M%S')}", styles["Normal"]))
+        elements.append(Spacer(1, 8))
+
+        # Items Table
+        data = [["Product_Code", "Qty", "Item", "Price"]]
+        for row in df.itertuples():
+            data.append([row.Product_Code, row.Qty, row.Category, f"{row.Price:.2f}"])
+        table = Table(data, colWidths=[40, 30, 70, 50])
+        table.setStyle(TableStyle([
+            ("GRID", (0, 0), (-1, -1), 0.5, colors.black),
+            ("FONTNAME", (0, 0), (-1, -1), "Courier"),
+            ("FONTSIZE", (0, 0), (-1, -1), 8),
+            ("ALIGN", (1, 1), (-1, -1), "CENTER"),
+            ("BACKGROUND", (0, 0), (-1, 0), colors.lightgrey),
+        ]))
+        elements.append(table)
+        elements.append(Spacer(1, 8))
+
+        # Totals
+        elements.append(Paragraph(f"Subtotal: {subtotal:.2f}", styles["Normal"]))
+        elements.append(Paragraph(f"Tax ({input.tax_rate()}%): {tax:.2f}", styles["Normal"]))
+        elements.append(Paragraph(f"<b>Total: {total:.2f}</b>", styles["Normal"]))
+        elements.append(Spacer(1, 8))
+
+        # Date/Time
+        elements.append(Paragraph(f"Date: {now.strftime('%d/%m/%Y')}", styles["Normal"]))
+        elements.append(Paragraph(f"Time: {now.strftime('%I:%M %p')}", styles["Normal"]))
+
+        doc.build(elements)
+
+        buffer.seek(0)
+        yield buffer.read()
+
+app = App(app_ui, server)