As requested in another thread here is how to setup a B4XPages app to use PyBridge and Folium in a webview.
Download latest beta version of B4J with PyBridge.
Make sure PyBridge is selected in the Libraries Manager Tab
Add folium to Python (pip install folium in a command prompt window for ypur Python, or use the Open local Python shell line below if python not installed)
B4X Code (B4XMainPage)
The Python code (either in-line or in a file)
Note in the following code the line with 'an email address' - the lookup requires an email address
Download latest beta version of B4J with PyBridge.
Make sure PyBridge is selected in the Libraries Manager Tab
Add folium to Python (pip install folium in a command prompt window for ypur Python, or use the Open local Python shell line below if python not installed)
B4X Code (B4XMainPage)
B4X:
#CustomBuildAction: after packager, %WINDIR%\System32\robocopy.exe, Python temp\build\bin\python /E /XD __pycache__ Doc pip setuptools tests
'Export as zip: ide://run?File=%B4X%\Zipper.jar&Args=Project.zip
'Create a local Python runtime: ide://run?File=%WINDIR%\System32\Robocopy.exe&args=%B4X%\libraries\Python&args=Python&args=/E
'Open local Python shell: ide://run?File=%PROJECT%\Objects\Python\WinPython+Command+Prompt.exe
'Open global Python shell - make sure to set the path under Tools - Configure Paths. Do not update the internal package.
'ide://run?File=%B4J_PYTHON%\..\WinPython+Command+Prompt.exe
Sub Class_Globals
Private Root As B4XView
Private xui As XUI
Public Py As PyBridge
Private WebView1 As WebView
Private Button1 As Button
End Sub
Public Sub Initialize
End Sub
'This event will be called once, before the page becomes visible.
Private Sub B4XPage_Created (Root1 As B4XView)
Root = Root1
Root.LoadLayout("MainPage")
Py.Initialize(Me, "Py")
Dim opt As PyOptions = Py.CreateOptions("d:/python.3.12.8/python.exe") ' change to where your python is if required
Py.Start(opt)
Wait For Py_Connected (Success As Boolean)
If Success = False Then
LogError("Failed to start Python process.")
Return
End If
End Sub
Sub Button1_Click
folium_test
End Sub
Private Sub B4XPage_Background
Py.KillProcess
End Sub
Private Sub Py_Disconnected
Log("PyBridge disconnected")
End Sub
Sub folium_test
' I read from dir assets but the code could be a string in-line.
' change the Array to contain a string of where you want the map to open eg "London, UK" from "Toronto, CA"
wait for ((Py.RunCode("start",Array("Toronto, CA"),File.ReadString(File.DirAssets,"folium_test.py")).Fetch)) Complete (res As PyWrapper)
' load the produced html file into a webview (it is fully functional web page and will open in browser too if you want)
WebView1.LoadHtml(File.ReadString("../objects",res.value))
End SubThe Python code (either in-line or in a file)
Note in the following code the line with 'an email address' - the lookup requires an email address
B4X:
import folium
import requests
def get_lat_lon(place_name):
url = f"https://nominatim.openstreetmap.org/search?q={place_name}&format=json"
headers = {
'User-Agent': 'AddressLookup/1.0 (an email address)'
}
response = requests.get(url, headers=headers)
if response.status_code == 200:
try:
data = response.json()
if data:
lat = data[0]['lat']
lon = data[0]['lon']
return lat, lon
else:
print("No data found for the specified place name.")
return None
except ValueError:
print("Invalid JSON response.")
return None
else:
print(f"Error: {response.status_code}")
return
def start(place):
lat,lon = get_lat_lon(place)
# Create a map centered around Lat/Lon
map_london = folium.Map(location=[lat,lon], zoom_start=12)
# Add a marker for Home
folium.Marker(
location=[lat,lon],
popup="Marker",
icon=folium.Icon(icon="Marker")).add_to(map_london)
# Save the map to an HTML file -- change the name to what you want, it will be saved in /Objects folder
map_london.save("london_map.html")
# return the name of the file to B4J
return "london_map.html"
Last edited:
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