Convert GeoJSON to TopoJSON. GeoJSON is an open standard format designed for representing simple geographical features, along with their non-spatial attributes, based on JavaScript Object Notation. The need of conversion is to reduce the size of data, so that rendering of data on browser can be made faster. TopoJSON (topological geospatial data) is an extension of GeoJSON that encodes topology. Here we have explored two methods for conversion of GeoJSON to TopoJSON (i.e. online and offline).
You can directly convert GeoJSON to TopoJSON with the help of topojoson-server node package manager. For using this package you need to first install node js in your system (can be installed in windows, linux based operating system or Mac).
NPM (Node Package Manager) is a command-line utility that aids in package installation, version management, and dependency management or can be considered npm as a tool that helps to install another tools like topojson-server.
For this method you need to download node.js which is available https://nodejs.org/en/ here. After successful installation you need to check npm availability using command
npm –check.
If not available use
npm install -g npm-check
convert geojson to topojson
After this you need to install topojson-server for conversion of data that can be done by using
npm install -g topojson-server
Now all setup is ready
Use geo2topo command to convert geojson data to topojson data
geo2topo –o geo.json topo.json
Where geo.json is the geojson file i.e input file and topo.json is the file we are creating with the name topo as topo.json file i.e output file.
Here –o is output. If command doesn’t run and gives error as no such file or directory. Then specify full path for file for both input and output. It is recommended that you run this command from the same directory where geo.json file is stored.
If you don’t have any input files ready or any geojson or shapefile then you can download free GIS data fromat for testing this article.
Online method: Convert GeoJson to TopoJson
This is the simple and fast method. For the conversion you just need to drag the geojson file in http://mapshaper.org/ site. Then use export option to convert this data into topojson format. Map shaper website render and convert the file in the browser itself, but it you might face problem while converting a big geojson file.
I hope that this methods listed above to convert geojson to topojson would have helped you in achieving result. If you find any problem or know any other method to perform this operation and want to share with us, then do let us know by commenting below, in the box provided.
Are you looking to create a map interactive application to locate markers with points, or to highlight an area by polygon or to draw or show a river or roads line with polyline? With Leafletjs library and GeoJSON as GIS data, we can easily create a map which we are looking for and render the output in browser. Leaflet js is an opensource small library to create interactive map. GeoJSON is one of the GIS data structure which stores geographic data in JSON format. GeoJSON supports point, line, polygon, multipolyline, multipolygon and Geometry collection which can represent a geometry, feature or a collection of features. A detailed structure of GeoJSON would be written in separate article.
Add or Load GeoJSON file
This Article would let you know how to render and load geoJSON file with the help of leaflet js library. Also you would also get an idea by this article to implement a click event over a GeoJSON file and fetch information associated with the feature of GeoJOSN data loaded as map.
Above script would output and render an osm base map. Now lets start adding different features on map one by one with GeoJSON file.
Add or Load GeoJSON file – Load Polygon with leaflet on Map:
Add following script, and replace the ‘usa_adm.geojson’ to the file you are want to render.
// loading GeoJSON file - Here my html and usa_adm.geojson file resides in same folder
$.getJSON("usa_adm.geojson",function(data){
// L.geoJson function is used to parse geojson file and load on to map
L.geoJson(data).addTo(newMap);
});
After adding the polygon layer you may want to view or load the map area covered or extended by the polygon GeoJSON file. i.e On Map load you want to zoom and pan according to the extent or to fit layer bounds. For this, Leafletjs provided a function to calculate the bounding box of the geojson file or layer i.e layer.getBounds(). And also with leaflet map fitBounds function i.e map.fitBounds(“bounding coordinates”). Here is the line which you needs to add to script:
newMap.fitBounds(datalayer.getBounds());
Finally, we are left only adding a click event to get the features data. With the help of Leaflet L.geoJson optional object parameter with key “onEachFeature“, we can add and define click event on every feature of the layer.
Here we would be fetching the attribute data of the feature clicked on Polygon GeoJOSN file. So before writing any script, we need to list out the feature properties list. You can get those properties key name easily if you are familiar with JSON files and structure.
So lets define a function named as onEachFeature and replace the ‘key’ keyword with your actual feature properties key of GeoJSON file:
So your final leaflet geojson code combines as i.e For adding polygon GeoJSON file on map, with click event and fit to extent functionality.
$.getJSON("usa_adm.geojson",function(data){
// add GeoJSON layer to the map once the file is loaded
var datalayer = L.geoJson(data ,{
onEachFeature: function(feature, featureLayer) {
featureLayer.bindPopup(feature.properties.NAME_1);
}
}).addTo(newMap);
newMap.fitBounds(datalayer.getBounds());
});
As I have loaded a US administrative polygon GeoJSON here, we can see following output as :
Add or Load GeoJSON file – polygon
Add or Load GeoJSON file – polyline on Leaflet Map:
Adding polyline Geojson with leaflet library is same as adding polygon file. So the above code would work for loading polyline GeoJSON file. Just you need to replace the file name with your polyline GeoJSON file and features properties key have to replaced by the actual key name, of which you want to retrive information.
Add or Load GeoJSON file – polyline
Add or Load GeoJSON file – point with Leaflet js on Map:
Adding Point GeoJSON file is same as loading Polygon GeoJSON file. Here is the output you can see for the famous world Cities.
Add or Load GeoJSON file – point
If you find any difficulty in adding or loading GeoJSON file on map with leaflet library, do comment below with your queries.
Convert Shapefile to GeoJSON. Shapefile, ESRI made a standard vector file format which is largely adopted in the field of GIS by programmers and geographers . While GeoJSON is also an open standard format designed for Web which largely supported with GIS JavaScript API, other programming API and with GIS (Geographic Information System) software tools too, for easily rendering. GeoJSON is based on JavaScript Object Notation. Here we will explore different methods to convert the files online, or offline or with the help of API which programmers can make use of.
You may be interested to refer following articles:
The simplest and fast way to access the internet is through the online method, as you don’t need to install and configure any tool on your PC. Just drag the Shapefile files, one click on button and convert to GeoJSON. There are many website which provides the tool to convert the files by browsing them to server side and convert and also some client side conversion too. Lets explore the list, which is only client side as client side conversion will secure your file and doesn’t take your data pack for uploading the file:
If you are already registered then login otherwise sign up.
Once get register tap on Converter Button Shown in figure.
Upload the Shapefile from data set or Google Drive or Drop Box or already added in drive then choose the file. Lets we want to convert already uploaded file from My Drive then select the file.
Tap the file and new window will appear shown below.
Select the desired Output in our case choose Geojson. You can also change CRS. Now tap on Convert file button.
It will so the table in the next step. You can directly download the converted file or you can check it through clicking on publish button.
Below is the screen of published Geojson file.
Whole process is same from new uploaded file from data set or from google drive or from drop box. If you face any problem ping us at website.
You might be interested in Query on Geojson data file then try our tool IGIS Map tool.
This is presented by Engineer Philosophy pvt. ltd, working in GIS Sector an IT company. What you need to do is to just Register, login and upload only .shp and .dbf file and then export the uploaded layer to GeoJSONfile by just selecting the option which appear at upper right corner in Navigation bar. You can also explore the attribute table from the website directly and filter the same which no other online tool provides.
different ways to convert Shapefile to Geojson – Online or Offline or API
Not only this, but you can classify the Map according to the shapefile dbf attributes and automatically classify and color it. The classified map can be exported as Scalable Vector Graphics i.e svg file.
Disclaimer: The above project is handled by me and my team and the project is in beta phase while you can definetly convert the shapefile to GeoJSON at client side securing your shapefile data. I would welcome your suggestion to improve the tool by commenting below or contacting me.
Map Shapper is the best tool which we should refer first. It is the best online tool which also handles large shapefiles and renders it quickly. Its an open source project and is licensed under MPL 2.0. Just drag the shapefile or zipped shapefile which will render the shapefile on map and can be further exported as geojson file with the option provided in tool itself.
With No doubt Map Shaper is much more better than any other tool for now, while the only reason why I placed this tool in second place just because the first tool was my own tool which provides more option for classifying the map, see all attributes in the data table and also exported as svg file.
2.) Offline Method – Convert Shapefile to GeoJSON in QGIS:
1.) Open QGIS Desktop and Select Layer -> Add Layer -> Add Vector Layer or click on Add Vector layer icon appears at the upper left in the application.
different ways to convert Shapefile to Geojson – Online or Offline or API
2.) Select the zipped shapefile or any of file i.e .shp or .dbf or .shx by browing the folder. Note, that all the three files i.e .shp, .dbf and .shx file should be present in the same foder with same name.
3.) Once uploaded, the map will be rendered and showed in QGIS application. Now navigate to Layer menu and select Save As option or just from the layers panel select the layer and right click from it to select Save As option.
4.) A window pop up will opne up. From the window just select the GeoJSON format and provide the name of the file in the input box as shown in the image provided below. Save the file. It will export the file in GeoJSON format.
3.) Offline Method – Convert Shapefile to GeoJSON with command line ogr2ogr tool:
Firstly you need to install an ogr2ogr tool of GDAL which is a GIS utlitly command line tool so as to convert one file to another. Now if the ogr2ogr is installed globally check by simple tying the ogr2ogr in command line if it is working or not. Or if it residing in some file system you need to navigate to ogr2ogr file and type in the same in command line. Now Just type in the following:
To get more option list and format you may see this gdal org link.
This tool will be helpful if you want to convert bulk files from shapefile to geojson. You can refer the .sh script found at github.
4.) Convert Shapefile to GeoJSON -API or library:
Shapefile is a binary file and cannot be viewed directly in notepad or textpad as like with GeoJSON file. So if you want to create your own API, to convert Shapefile to GeoJSON you should first have a knowledge of how to read the binary shapefile. You may refer to some of the articles which I have written some post which would help you to get the basic knowledge to know the format of files and read.
https://github.com/gipong/shp2geojson.js : This library is also MIT Licensed and is inspired by the above wavded library which uploads zipped file of shapefile. The library provided an example to use with leaflet js.
https://github.com/mbloch/mapshaper : Map Shaper as desricbed above is licensed under MPL 2.0 and can be very useful if you want to convert to GeoJSON as well as TopoJSON.
Hope this article helped you. If are facing some problem in converting the shapefile to geojson do comment below with the problem statement. We will definitely look over that. Also you can provide your valuable comment below if you are using any other library or tool to cover the same.
