B4J Code Snippet Two geodesic features on a web page using B4J+Python (with sources)

MichalK73

Active Member
Licensed User
Hello.

I haven't seen the available B4X libraries for geodetic conversion, and rewriting them is very complicated computationally. Since at work, I often uses the transformation between coordinate systems, i decided to make it easier for myself and my colleagues at work. I used ABMaterial and Python for this. ABMaterial is responsible for the web page, python is responsible for converting between coordinate systems. Additionally, the function of searching for the coordinates of the specified address is added. The site operates in Polish language and are included coordinate systems that are most often used in my country. Python scripts I wrote myself and work with b4x code. The python script is over shell with parameters.

B4J function to search coordinates with a Shell call.:
Public Sub find(adres As String)As ResumableSub
    Log(adres)
    Dim shl As Shell
    #if release
    shl.Initialize("shl", "python3", _
     Array As String("adres.py", adres))
    #else
    shl.Initialize("shl", "python", _
     Array As String("adres.py", adres))
    #end if
    shl.WorkingDirectory = File.DirApp
    shl.Run(10000) 'set a timeout of 10 seconds
    Wait For shl_ProcessCompleted (Success As Boolean, ExitCode As Int, StdOut As String, StdErr As String)

    Dim j As JSONParser
    j.Initialize(StdOut)
    Dim m As Map
    m.Initialize
    m = j.NextObject
    Dim out As StringBuilder
    out.Initialize

    out.Append("Adres: "&m.Get("adres")).Append(CRLF).Append(CRLF)
    m.Remove("adres")
  
    For i=0 To m.Size-1

        Dim m1 As Map = m.GetValueAt(i)

        out.Append("{B}"&m.GetKeyAt(i)&"{/B}").Append(" :     ").Append(m1.GetValueAt(0)).Append(" , ").Append(m1.GetValueAt(1)).Append(CRLF)
    Next
    Dim jj As JSONGenerator
    jj.Initialize(m)
    If StdErr <> "" Then
        Return StdErr
    Else
        Return out.ToString
      
    End If
End Sub
B4J function to convert coordinates with a Shell call.:
'src- uklad z ktorego jest konwersja
'out - uklad na ktory ma byc dokonana zamiana
'zamiana - zamiana X z Y
public Sub convertData(value As String, src As String, out As String, zamiana As String) As ResumableSub
    Dim nazwa As String = Rnd(10000,50000)
    File.WriteString(File.DirApp, nazwa,value)
    Dim shl As Shell
  
    Dim paramerty As String = """"& nazwa & "," & src & "," & out & "," &zamiana &""""

    #if release
    shl.Initialize("shl", "python3", _
     Array As String("convert.py", paramerty))
    #else
    shl.Initialize("shl", "python", Array As String("convert.py", paramerty ))
'    shl.Initialize("shl", "python", Array As String("convert.py", paramerty))
    #end if
    shl.WorkingDirectory = File.DirApp
    shl.Run(10000) 'set a timeout of 10 seconds
    Wait For shl_ProcessCompleted (Success As Boolean, ExitCode As Int, StdOut As String, StdErr As String)

'  
    Return StdOut

End Sub

Call coordinate conversions from data from a web page.:
    Dim rs As ResumableSub = ap.convertData(dane.Text, inp.GetActiveItemId, out.GetActiveItemId, z)
    Wait For(rs) Complete (Result As String)
    Dim lab As ABMLabel = page.Component("out")
    lab.Text = Result
    lab.Refresh
Call coordinate scans from the specified address.:
    page.ShowToast("ok", "", "Szukam ...", 2000, False)
    Dim rs As ResumableSub = ap.find(value)
    Wait For(rs) Complete (Result As String)
    Dim lab As ABMLabel = page.Component("out")
    lab.Text = Result
    lab.Refresh
Python convert address to coordinates.:
#!/usr/bin/env python
# coding: utf-8



##Układ współrzędnych 1965 (strefa I) – EPSG:3120
##Układ współrzędnych 1965 (strefa II) – EPSG:2172
##Układ współrzędnych 1965 (strefa III) – EPSG:2173
##Układ współrzędnych 1965 (strefa IV) – EPSG:2174
##Układ współrzędnych 1965 (strefa V) – EPSG:2175
##
##Układ 1992 EPSG:2180
##
##Układ współrzędnych 2000 (strefa V) – EPSG:2176
##Układ współrzędnych 2000 (strefa VI) – EPSG2177
##Układ współrzędnych 2000 (strefa VII) – EPSG:2178
##Układ współrzędnych 2000 (strefa VIII) – EPSG:2179


from geopy.geocoders import ArcGIS
from pyproj import Transformer
import sys
import json
import re


nom =ArcGIS()

WEJSCIE =''
WYJSCIE =''


def trans(adres):
    uklad = {
                '65/1':'3120',
              '65/2' : '2172',
              '65/3' : '2173',
              '65/4' : '2174',
              '65/5' : '2175',
              '1992' : '2180',
              '2000/5' : '2176',
              '2000/6' : '2177',
              '2000/7' : '2178',
              '2000/8' : '2179'
              }

    result = nom.geocode(adres)
    adress = result[0]
    ws = result[1]
    x1 = ws[0]
    y1 = ws[1]

    out={}
    out['adres'] = adress
    for k,v in uklad.items():
        transformer = Transformer.from_crs("epsg:4326", "epsg:"+v)
        x0,y0 = transformer.transform(x1, y1)
        x0 = ('%.2f' %x0)
        y0 = ('%.2f' %y0)
        out[k]= {'x':x0, 'y':y0}

    j = json.dumps(out)
    print(j)

if __name__ == '__main__':

    par  = sys.argv[1]
    trans(par)
Python converts from one layout to the other coordinates.:
#!/usr/bin/env python
# coding: utf-8



##Układ współrzędnych 1965 (strefa I) – EPSG:3120
##Układ współrzędnych 1965 (strefa II) – EPSG:2172
##Układ współrzędnych 1965 (strefa III) – EPSG:2173
##Układ współrzędnych 1965 (strefa IV) – EPSG:2174
##Układ współrzędnych 1965 (strefa V) – EPSG:2175
##
##Układ 1992 EPSG:2180
##
##Układ współrzędnych 2000 (strefa V) – EPSG:2176
##Układ współrzędnych 2000 (strefa VI) – EPSG2177
##Układ współrzędnych 2000 (strefa VII) – EPSG:2178
##Układ współrzędnych 2000 (strefa VIII) – EPSG:2179


from geopy.geocoders import ArcGIS
from pyproj import Transformer
import sys, os
import json
import re


nom =ArcGIS()

WEJSCIE =''
WYJSCIE =''


def trans(adres):
    uklad = {
                '65/1':'3120',
              '65/2' : '2172',
              '65/3' : '2173',
              '65/4' : '2174',
              '65/5' : '2175',
              '1992' : '2180',
              '2000 V' : '2176',
              '2000 VI' : '2177',
              '2000 VII' : '2178',
              '2000 VIII' : '2179'
               }

    result = nom.geocode(adres)
    adress = result[0]
    ws = result[1]
    x1 = ws[0]
    y1 = ws[1]

    out={}
    out['adres'] = adress
    for k,v in uklad.items():
        transformer = Transformer.from_crs("epsg:4326", "epsg:"+v)
        x0,y0 = transformer.transform(x1, y1)
        x0 =int(x0)
        y0 = int(y0)
        out[k]= {'x':x0, 'y':y0}

    j = json.dumps(out)
    print(j)

def setUklad(wejscie, wyjscie):
    global WEJSCIE, WYJSCIE
    if wejscie == 'WGS84':
        WEJSCIE = 'epsg:4326'
    elif wejscie == '65/1':
        WEJSCIE = 'epsg:3120'
    elif wejscie == '2000/5':
        WEJSCIE = 'epsg:2176'
    elif wejscie == '2000/6':
        WEJSCIE = 'epsg:2177'
    elif wejscie == '2000/7':
        WEJSCIE = 'epsg:2178'
    elif wejscie == '2000/8':
        WEJSCIE = 'epsg:2179'
    elif wejscie == '1992':
        WEJSCIE = 'epsg:2180'

    if wyjscie == 'WGS84':
        WYJSCIE = 'epsg:4326'
    elif wyjscie == '65/1':
        WYJSCIE = 'epsg:3120'
    elif wyjscie == '65/2':
        WYJSCIE = 'epsg:2172'
    elif wyjscie == '65/3':
        WYJSCIE = 'epsg:2173'
    elif wyjscie == '65/4':
        WYJSCIE = 'epsg:2174'
    elif wyjscie == '65/5':
        WYJSCIE = 'epsg:2175'
    elif wyjscie == '1992':
        WYJSCIE = 'epsg:2180'
    return

def oneTransorm(x, y):
    global WEJSCIE, WYJSCIE
    transformer = Transformer.from_crs(WEJSCIE, WYJSCIE)
    x0,y0 = transformer.transform(x,y)
    out=[]
    out.append(x0)
    out.append(y0)
    return out

def convertData(value):
    lista = value.split(",")
    setUklad(lista[1], lista[2])
    zamiana = lista[3]
    out =''
    value = open(lista[0] , 'r').read()
##    value.close()
    os.remove(lista[0])
    lista = value.split('\n')
    for line in lista:
        if len(line) > 10:
            line = line.split(',')
            if str(zamiana) == 'true':
                y = line[1]
                x = line[2]
            else:
                x = line[1]
                y = line[2]
            result = oneTransorm(x,y)
            x0 = ('%.2f' %result[0])
            y0 = ('%.2f' %result[1])
            out = out+('%s,%s,%s,1' %(line[0],x0,y0))+'\n'

    print(out)

par  = sys.argv[1]
convertData(par)
You can recalculate one point or multiple point rows.
Input structure:
sequence number,x position,y position, height
(height is not relevant here).
Eg. (2000/7 input)
1,56800629.93,7404869.63,1
1.png 2.png

To fully compile, you need to upload the contents of the 'www' package from ABMaterial to the Objects folder.
The address of the working page described as an example of a B4X connection to Python.
Everyone can see how this works with b4x with python in the attached sources.

The address of the working page. Working Page
 

Attachments

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