inventree-phomemo-plugin/inventree_phomemo/phomemo_label.py

# django
from django.utils.translation import gettext_lazy as _
from django.core.validators import MinValueValidator
from django.core.validators import MaxValueValidator
from django.http import JsonResponse

# printer support
import requests

# barcode helpers
from InvenTree.helpers_model import getModelsWithMixin
from InvenTree.models import InvenTreeBarcodeMixin

# InvenTree plugin libs
from plugin import InvenTreePlugin
from plugin.mixins import LabelPrintingMixin, SettingsMixin, BarcodeMixin
from label.models import LabelTemplate

from inventree_phomemo.version import PHOMEMO_PLUGIN_VERSION

class PhomemoLabelPlugin(LabelPrintingMixin, BarcodeMixin, SettingsMixin, InvenTreePlugin):
    AUTHOR = "Sergal.engineering"
    DESCRIPTION = "Label printing plugin for Phomemo printers"
    VERSION = PHOMEMO_PLUGIN_VERSION
    NAME = "Phomemo"
    SLUG = "phomemo"
    TITLE = "Phomemo Label Printer"

    SETTINGS = {
        'URL': {
            'name': _('URL'),
            'description': _('URL of the print endpoint'),
            'default': 'http://localhost:8080/print',
        },
    }

    def get_fields(self, label_instance):
        object_to_print = label_instance.object_to_print

        match label_instance.SUBDIR:
            case 'part':
                tpart = object_to_print
                barcode = '1' + str(object_to_print.pk)
            case 'stockitem':
                tpart = object_to_print.part
                barcode = '2' + str(object_to_print.pk)
            case 'stocklocation':
                tpart = object_to_print
                barcode = '3' + str(object_to_print.pk)
            case 'build':
                tpart = object_to_print
                barcode = '4' + str(object_to_print.pk)
            case _:
                tpart = object_to_print
                barcode = '0' + str(object_to_print.pk)
                print(f"!! Unsupported item type: {label_instance.SUBDIR}")
        
        fields = {
            'name': tpart.name,
            'description': tpart.description,
            'pk': tpart.pk,
            'params': tpart.parameters_map() if hasattr(tpart, 'parameters_map') else None,
            'category': tpart.category.name if hasattr(tpart, 'category') else None,
            'category_path': tpart.category.pathstring if hasattr(tpart, 'category') else None,
            'barcode': barcode,
            'type': label_instance.SUBDIR,
            'width': label_instance.width,
            'height': label_instance.height
        }

        return fields

    def print_labels(self, label: LabelTemplate, items: list, request, **kwargs):
        outputs = []

        # Get label content for every label
        for item in items:
            label.object_to_print = item
            outputs.append(self.get_fields(label))

        # Read settings
        url = self.get_setting('URL')

        # Send the label to the printer
        r = requests.post(url, json=outputs)
        r.raise_for_status()
        
        return JsonResponse({
            'success': True,
            'message': f'{len(items)} labels printed',
        })


    @staticmethod
    def get_supported_barcode_models():
        """Returns a list of database models which support barcode functionality."""
        return getModelsWithMixin(InvenTreeBarcodeMixin)

    def format_matched_response(self, label, model, instance):
        """Format a response for the scanned data."""
        return {label: instance.format_matched_response()}
    
    def scan(self, barcode_data):
        # Our barcode should be a string
        if type(barcode_data) is not str:
            barcode_data = str(barcode_data)
        
        # Our barcodes are at least two symbols long
        if len(barcode_data) < 2:
            return
        
        match barcode_data[0]:
            case '1':
                model_type = 'part'
            case '2':
                model_type = 'stockitem'
            case '3':
                model_type = 'stocklocation'
            case '4':
                model_type = 'build'

        supported_models = self.get_supported_barcode_models()

        for model in supported_models:
            label = model.barcode_model_type()

            if label == model_type:
                try:
                    pk = int(barcode_data[1:])
                    instance = model.objects.get(pk=pk)
                    return self.format_matched_response(label, model, instance)
                except (ValueError, model.DoesNotExist):
                    pass