geospatial-services-framework
GSF JavaScript Client SDK
About the SDK
The GSF JavaScript Client SDK provides a client-side JavaScript library for interacting with GSF. The SDK may be used in the browser as well as Node.js. For detailed information visit our full developer documentation page.
- This repository contains pre-built distributable files located in the
/dist/directory./dist/GSF-node.js- The Node.js bundle./dist/GSF-node.js.map- The Node.js bundle source map./dist/GSF.js- The non-minified web bundle./dist/GSF.js.map- The non-minified web bundle source map file./dist/GSF.min.js- The minified web bundle./dist/GSF.min.js.map- The minified web bundle source map file.
Installation
The SDK can be installed using npm.
$ npm install gsf-js-client-sdk --saveImporting the SDK
Using ECMAScript 2015
Import everything with GSF namespace:
import * as GSF from 'gsf-js-client-sdk';Import specific classes:
import { Job, Task } from 'gsf-js-client-sdk';
Using Node.js
Require the SDK:
const GSF = require('gsf-js-client-sdk/dist/GSF-node');
Including the SDK with a Script Tag
Include the GSF JavaScript Client SDK file in your project. The example below assumes the SDK file is located next to your html file.
<script src="GSF.min.js"></script>Access the SDK using the global GSF object.
<script>console.log(GSF);</script>
Basic Example
- Below is a simple example of running a job and retrieving the results. You will need to update the server address and port below to reflect the server that you are using.
const myAddress = 'MyServer';
const myPort = 9191;
// GSF Client
const client = GSF.client({
address: myAddress,
port: myPort
});
// Create a service object.
const service = client.service('ENVI');
// Create a task object.
const task = service.task('SpectralIndex');
const NDVIParameters = {
inputParameters: {
INPUT_RASTER: {
FACTORY: 'URLRaster',
URL: 'http://' + myAddress + ':' + myPort + '/ese/data/qb_boulder_msi'
},
INDEX: 'Normalized Difference Vegetation Index'
}
};
// Submit a job.
task.submitAndWait(NDVIParameters).then((results) => {
// Do something with results.
AddToMap(results.OUTPUT_RASTER.best);
}).catch((err) => {
// Display error.
});TypeScript Example
Below is an example of submitting a job using typescript.
import * as GSF from 'gsf-js-client-sdk';
// Get a task.
const clientOpts: GSF.ClientOptions = {
address: 'MyServer',
port: '9191'
};
const client: GSF.Client = GSF.client(clientOpts);
const ENVIService: GSF.Service = client.service('ENVI');
const myTask: GSF.Task = ENVIService.task('SpectralIndex');
const taskParameters: GSF.SubmitOptions = {
inputParameters: {
INPUT_RASTER: {
FACTORY: 'URLRaster',
URL: 'http://MyServer:9191/ese/data/qb_boulder_msi'
},
INDEX: 'Normalized Difference Vegetation Index'
}
};
// Submit a job.
task.submitAndWait(taskParameters)
.then((results: GSF.JobResults) => {
// Do something with results.
// This function is an example and is not provided by the SDK.
AddToMap(results.OUTPUT_RASTER.best);
}).catch((jobErrorMessage) => {
// Display error.
});This is just a sample of what can be done with the SDK. See our full developer documentation to learn more.
Requirements
Server Sent Events
The GSF JavaScript Client SDK relies on server-sent events for communication with the server. Developers who wish to build apps that run on browsers lacking EventSource support will want to use a polyfill. This is not necessary when using the SDK in Node.js.
To view a list of the browsers that support EventSource go here: https://caniuse.com/#search=eventsource
There are several polyfills available that provide implementations of the EventSource API. One such polyfill that is available from the npm and Bower package managers is called 'eventsource-polyfill'. For information on installation and usage, see https://github.com/amvtek/EventSource.
Developer Documentation
Visit our full developer documentation page for more information.