geojson

Bahan ajar pengenalan geojson https://bukped.github.io/geojson/

Chapter 1

Adding your Desktop SSH Key to Github

1. Make sure you read this section https://github.com/awangga/nopanel/blob/master/git.md
2. Fork this repo
3. Clone into your desktop using git clone ssh
4. Set upstream first
5. Working in your task
6. Pull request after fetch upstream

Task

1. Select a place in Bandung City (Public Place, Government Place, Edu Place)
2. Create 10 poligon type in that place store in bandung folder, save it ad geojson format and rename it to placename.json
3. Insert it into mongo db provided by lecturer using mongo compass https://www.mongodb.com/products/compass
4. Pull Request Subject : 8-KELAS-NPM-NAMA
5. Go home

Chapter 2 : Fixing Invalid Geometry Data

Source Data

1. http://download.geofabrik.de/asia/indonesia.html
2. https://openstreetmap.or.id/en/data-openstreetmap-indonesia/
3. https://www.arrayiterator.com/kodepos-geocoding-json-seluruh-indonesia-sesuai-bps
4. https://ibnux.github.io/data-indonesia/
5. https://github.com/superpikar/indonesia-geojson
6. https://github.com/pararawendy/border-desa-indonesia-geojson use string replace

For pararawendy/border-desa-indonesia-geojson data, to change into GeoJSON standar format :

replace : "border":[[[
with : "border":[[

AND

replace : ]]]}
with : ]]}

THEN

replace : "border":[
with : "border":{"type":"Polygon","coordinates": [[

AND

replace : ]}
with : ]]}}

Mongo basic for Geojson

Query with current coordinat

{
  border: {
     $geoIntersects: {
        $geometry: {
           type: "Point" ,
           coordinates: [ 107.575902278736,-6.8732786951873255 ]
        }
     }
  }
}

Task

1. You might Using google colab to download data and mongo db tools it into your google drive.

import os
from google.colab import drive
drive.mount('/content/drive')
folder = '/content/drive/My Drive/Download/dl' 

savedir=folder
os.chdir(savedir)  #change dir
!pwd
!ls
!pip install pygeos
!pip install pyrosm
!wget https://fastdl.mongodb.org/tools/db/mongodb-database-tools-ubuntu1804-x86_64-100.6.1.deb
!sudo apt install ./mongodb-database-tools-ubuntu1804-x86_64-100.6.1.deb
!curl http://ip-api.com/json
!wget https://github.com/pararawendy/border-desa-indonesia-geojson/raw/master/indonesia_villages_border.geojson.zip
!unzip indonesia_villages_border.geojson.zip

to manipulate the data you might use this script

# Read in the file
with open('indonesia_villages_border.geojson', 'r') as file :
  filedata = file.read()

# Replace the target string
filedata = filedata.replace('"border":[[[', '"border":[[')
filedata = filedata.replace(']]]}', ']]}')
filedata = filedata.replace('"border":[', '"border":{"type":"Polygon","coordinates": [[')
filedata = filedata.replace(']}', ']]}}')

# Write the file out again
with open('village.geojson', 'w') as file:
  file.write(filedata)

2. Cree free tier database from mongodb.com connect it with your mongo compass. Add query IP Address from step 1. and create db, collection and index with colab.Choose one city/residence, make sure city different from other insert the city data into your mongodb using colab or compass. Import to notvalid collection first.

!mongoimport --uri="mongodb+srv://awangga:rollyganteng@serverlessinstance0.wginu.mongodb.net/location" --collection=notvalid village.geojson --jsonArray

3. Make sure you have set index for border field in 2d geosphere.

import pymongo

mongostring="mongodb+srv://user:pass@dbname.host.mongodb.net/"
myclient = pymongo.MongoClient(mongostring)
mydb = myclient["location"]
mycol = mydb["villages"]
mycol.drop()
mydb = myclient["location"]
mycol = mydb["villages"]
mycol.create_index( [("border" , pymongo.GEOSPHERE )] )
!mongoimport --uri="mongodb+srv://user:pass@dbname.host.mongodb.net/location" --collection=villages village.geojson --jsonArray

4. Solving Edge or geometri invalid format. You might using pygeos, geojson.io or other visualization tools.
5. Export it and convert to geojson format like in https://leafletjs.com/examples/geojson/ put in in data folder with city name.json (example: ulbi.json)

    {
      "type": "Feature",
      "properties": {
        "name": "ALUE BULOH"
      },
      "province": "ACEH",
      "district": "ACEH TIMUR",
      "sub_district": "BIREM BAYEUN",
      "village": "ALUE BULOH",
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              97.9666,
              4.4451
            ],
            [
              97.9665,
              4.4451
            ],
             [
              97.9665,
              4.4451
            ],
            [
              97.9666,
              4.4451
            ]
          ]
        ]
      }
    }

6. Pull Request Subject : 9-KELAS-NPM-NAMA ,
7. Description : please include your screenshoot of indexes and mongo compass access
8. After Approved you are done

Chapter 3 : Javascript preparation

Here

Chapter 4 : Geojson Webservice

Here