[FIXED] How to Get ID and How to Bind Kivymd Input Field without Kivy file

Issue

Good day guys,

Please am new to python and I have a little project am working on. The project generates input field base on barcode scanned, and each input field has a unique id. Now my challenge is how can I bind or pass the instance of a particular input field to a function or get the ID of the input field currently been modified secondly when you click on the remove product I want the product attach to the button to be removed

from kivy.lang import Builder
from kivy.factory import Factory

from kivymd.app import MDApp

from kivy.uix.screenmanager import Screen

from kivymd.uix.textfield import MDTextField
from kivymd.uix.button import MDRectangleFlatButton
import weakref

from kivy.properties import DictProperty
from kivy.properties import ObjectProperty

Builder.load_string(
    """
<Windows>:
    ScrollView:
        MDBoxLayout:
            orientation: 'vertical'
            padding: '48dp'
            spacing: '15dp'
            size_hint_y: None
            height: self.minimum_height
            id: data_layout
            
            MDRaisedButton:
                text: "open_window 2"
                on_release: root.opener()
"""
)
    
class Windows(Screen):
    got_txt = ObjectProperty()
    dynamic_ids = DictProperty({})
    
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

    
    def opener(self):
        #print(window_id)
        #self.layout = GridLayout(cols = 5, row_force_default=True, row_default_height=40)
        #window_id.open()
        #self.table()
        self.read_barcodes()
        
    def build(self):
        self.root = Factory.Windows()
    
    def read_barcodes(self):
        
        barcode = ['sfdfdf','fdfdfdfd','sdfdfd']
        
        for barcode_info in barcode:
            #d =str( str(len(self.tables_data) + 1) + '',''+barcode_info)
            #self.tables_data.append('('+barcode_info+')')
            product_code_id = barcode_info + "_product_code"
            product_name_id = barcode_info + "_product_name"
            product_qty_id = barcode_info + "_product_qty"
            product_price_id = barcode_info + "_product_price"
            product_amount_id = barcode_info + "_product_amount"
            
            
            product_code = MDTextField(mode= "rectangle", text=str(barcode_info), readonly=True, opacity=0)
            self.ids.data_layout.add_widget(product_code)
            # We'll use a weak ref to add our dynamic id 
            self.ids[product_code_id] = weakref.ref(product_code)
            self.dynamic_ids[id] = product_code_id
            
            product_name = MDTextField(hint_text="Product Name",mode= "rectangle", text=str(barcode_info), readonly=True)
            #product_name.bind(on_focus=self.focusedInpute())
            self.ids.data_layout.add_widget(product_name)
            # We'll use a weak ref to add our dynamic id 
            self.ids[product_name_id] = weakref.ref(product_name)
            self.dynamic_ids[id] = product_name_id
            
            
            product_qty = MDTextField(hint_text="qty",mode= "rectangle", text=str(1))
            self.ids.data_layout.add_widget(product_qty)
            # We'll use a weak ref to add our dynamic id 
            self.ids[product_qty_id] = weakref.ref(product_qty)
            self.dynamic_ids[id] = product_qty_id
            
            product_price = MDTextField(hint_text="U.Price",mode= "rectangle",text=str(200))
            self.ids.data_layout.add_widget(product_price)
            # We'll use a weak ref to add our dynamic id 
            self.ids[product_price_id] = weakref.ref(product_price)
            self.dynamic_ids[id] = product_price_id
            
            product_amount = MDTextField(hint_text="Amount",mode= "rectangle", text=str(200))
            self.ids.data_layout.add_widget(product_amount)
            # We'll use a weak ref to add our dynamic id 
            self.ids[product_amount_id] = weakref.ref(product_amount)
            
            self.ids.data_layout.add_widget(MDRectangleFlatButton(text ="Remove Product"))
            
            #self.ids.data_layout.add_widget(layout) , on_release=self.Remove_line(barcode_info)
            
            #self.Reload_Table()
            
            print("The id is " + str(self.ids[product_code_id]))
            
            #print("The text is " + str(self.ids[product_code_id].text))
            
            self.scaned = barcode_info
            
            print(self.dynamic_ids)
            
    def Remove_line(self, widgets):
        print('hi')
        #self.ids.data_layout.remove_widget(widgets)
        #self.ids.data_layout.remove_widget(self.ids[widgets + "_product_code"])
        #self.ids.data_layoutr.emove_widget(self.ids[widgets + "_product_name"])
        #self.ids.data_layout.remove_widget(self.ids[widgets + "_product_qty"])
        #self.ids.data_layoutr.remove_widget(self.ids[widgets + "_product_price"])
        #self.ids.data_layoutr.remove_widget(self.ids[widgets + "_product_amount"])
        #remove_widget()
        
        
        
    def focusedInpute(self,insatnce, value):
        #print(self)
       # print(value)
        if not value:   # defocused
            print(value)

class MainApp(MDApp):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)


    def build(self):
        self.root = Factory.Windows()
    


if __name__ == "__main__":
    MainApp().run()

Solution

Here is a modified version of your code that allows you to delete the product and gets the id string of the input field and uses that to access the text:

from kivy.lang import Builder
from kivy.factory import Factory
from kivy.uix.boxlayout import BoxLayout
from kivymd.app import MDApp
from kivy.uix.screenmanager import Screen
from kivy.properties import DictProperty, StringProperty
from kivy.properties import ObjectProperty

Builder.load_string(
"""
<Windows>:
    ScrollView:
        MDBoxLayout:
            orientation: 'vertical'
            size_hint_y: None
            height: self.minimum_height
            id: data_layout

            MDRaisedButton:
                text: "open_window 2"
                pos_hint: {'center_x':0.5}
                on_release: root.opener()
                
<ProductLayout>:
    orientation: 'vertical'
    padding: '48dp'
    spacing: '15dp'
    size_hint_y: None
    height: self.minimum_height
    MDTextField:
        id: product_code
        mode: "rectangle"
        text: root.barcode_info
        readonly: True
        size_hint_y: None
        height: 0
        opacity: 0
    MDTextField:
        id: product_name
        hint_text: "Product Name"
        mode: "rectangle"
        text: root.barcode_info
        readonly: True
    MDTextField:
        sid: root.barcode_info + '_product_qty'
        id: product_qty
        hint_text: "qty"
        mode: "rectangle"
        text: str(1)
        on_text: root.text_changed(product_qty)
        on_focus: root.focus_changed(product_qty)
    MDTextField:
        sid: root.barcode_info + '_product_price'
        id: product_price
        hint_text: "U.Price"
        mode: "rectangle"
        text: str(200)
        on_text: root.text_changed(product_price)
        on_focus: root.focus_changed(product_price)
    MDTextField:
        sid: root.barcode_info + '_product_amount'
        id: product_amount
        hint_text: "Amount"
        mode: "rectangle"
        text: str(200)
        on_text: root.text_changed(product_amount)
        on_focus: root.focus_changed(product_amount)
    MDRectangleFlatButton:
        text: "Remove Product"
        on_release: root.parent.remove_widget(root)
"""
)


class ProductLayout(BoxLayout):
    barcode_info = StringProperty('')

    def text_changed(self, mdtf):
        # this gets called on every text change
        print('text changed for', self.barcode_info, ':')
        print('\t', mdtf.sid)
        print('\t', MDApp.get_running_app().root.ids[mdtf.sid].text)

    def focus_changed(self, mdtf):
        if not mdtf.focus:
            # this is run only when the text field loses focus
            print('focus changed to', mdtf.focus)
            print('\t', mdtf.sid)
            print('\t', MDApp.get_running_app().root.ids[mdtf.sid].text)


class Windows(Screen):
    got_txt = ObjectProperty()
    dynamic_ids = DictProperty({})

    def __init__(self, **kwargs):
        super().__init__(**kwargs)

    def opener(self):
        # print(window_id)
        # self.layout = GridLayout(cols = 5, row_force_default=True, row_default_height=40)
        # window_id.open()
        # self.table()
        self.read_barcodes()

    def build(self):
        self.root = Factory.Windows()

    def read_barcodes(self):

        barcode = ['sfdfdf', 'fdfdfdfd', 'sdfdfd']

        for barcode_info in barcode:
            # d =str( str(len(self.tables_data) + 1) + '',''+barcode_info)
            # self.tables_data.append('('+barcode_info+')')
            product_code_id = barcode_info + "_product_code"
            product_name_id = barcode_info + "_product_name"
            product_qty_id = barcode_info + "_product_qty"
            product_price_id = barcode_info + "_product_price"
            product_amount_id = barcode_info + "_product_amount"

            product_layout = ProductLayout(barcode_info=barcode_info)
            self.ids.data_layout.add_widget(product_layout)

            self.ids[product_code_id] = product_layout.ids.product_code
            self.dynamic_ids[id] = product_code_id

            self.ids[product_name_id] = product_layout.ids.product_name
            self.dynamic_ids[id] = product_name_id

            self.ids[product_qty_id] = product_layout.ids.product_qty
            self.dynamic_ids[id] = product_qty_id

            self.ids[product_price_id] = product_layout.ids.product_price
            self.dynamic_ids[id] = product_price_id

            self.ids[product_amount_id] = product_layout.ids.product_amount

            self.scaned = barcode_info

        print('dynamic ids:\n', self.dynamic_ids)
        print('ids:\n', self.ids)

    def Remove_line(self, widgets):
        print('hi')
        # self.ids.data_layout.remove_widget(widgets)
        # self.ids.data_layout.remove_widget(self.ids[widgets + "_product_code"])
        # self.ids.data_layoutr.emove_widget(self.ids[widgets + "_product_name"])
        # self.ids.data_layout.remove_widget(self.ids[widgets + "_product_qty"])
        # self.ids.data_layoutr.remove_widget(self.ids[widgets + "_product_price"])
        # self.ids.data_layoutr.remove_widget(self.ids[widgets + "_product_amount"])
        # remove_widget()

    def focusedInpute(self, insatnce, value):
        # print(self)
        # print(value)
        if not value:  # defocused
            print(value)


class MainApp(MDApp):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

    def build(self):
        return Windows()


if __name__ == "__main__":
    MainApp().run()

I have added a ProductLayout class that contains all the widgets for a product. That allows easy removal. And when each instance of ProductLayout is created, the ids are added to the ids dictionary of the Windows Screen. The on_text() or on_focus() methods can be used to access the text fields and their contained text.

Still don't understand the purpose of the dynamic_ids, but I left that code in.

Answered By - John Anderson