Recipes
*******

Common patterns for using pyStrich in real applications.

For one-off generation from a shell, see Command-line interface.


Serving barcodes from a web request
===================================

Every encoder has a "get_imagedata()" method that returns the PNG as a
"bytes" object, suitable for streaming straight back to a client
without touching the filesystem.

With Flask:

   from flask import Flask, Response
   from pystrich.code39 import Code39Encoder

   app = Flask(__name__)

   @app.route("/barcode/<text>")
   def barcode(text):
       encoder = Code39Encoder(text)
       return Response(encoder.get_imagedata(), mimetype="image/png")

The same pattern applies to FastAPI, Django, or any other framework --
the encoder produces raw PNG bytes that can be returned with the
"image/png" content type.


Generating barcodes in bulk
===========================

Each encoder constructs a fresh symbol; there is no shared state to
reset between calls. To generate many barcodes, loop over your inputs:

   from pathlib import Path
   from pystrich.code128 import Code128Encoder

   out = Path("labels")
   out.mkdir(exist_ok=True)

   for sku in ["A1266470501", "A1268206342", "A0001513255"]:
       Code128Encoder(sku).save(out / f"{sku}.png")


Loading the output into PIL for further processing
==================================================

To composite a barcode onto a label template, call "get_pilimage()" to
obtain a "PIL.Image.Image" directly:

   from PIL import Image
   from pystrich.datamatrix import DataMatrixData, DataMatrixEncoder

   payload = DataMatrixData("EMMETT", encoding="ascii")
   barcode = DataMatrixEncoder(payload).get_pilimage(cellsize=8)

   label = Image.new("RGB", (400, 200), "white")
   label.paste(barcode, (20, 20))
   label.save("label.png")


In-memory output
================

Every encoder has both raster and vector in-memory methods.
"get_imagedata()" returns PNG bytes (the in-memory equivalent of
"save()"); "get_svg()" returns an SVG string (the in-memory equivalent
of "save_svg()").

   from pystrich.qrcode import QRCodeEncoder

   encoder = QRCodeEncoder('{"institution": "New York University", "major": "Philosophy"}')

   png_data = encoder.get_imagedata()   # bytes -- attach to an email, store in a database
   svg_markup = encoder.get_svg()       # str  -- embed directly in an HTML response