jhvrequest

jhvrequest is a javascript package for sending SAMP requests to JHelioviewer

Usage

Install the package with npm

npm i jhvrequest

Import and make requests.

import { JhvRequestBuilder } from "jhvrequest";

// Load AIA 304 between 2023-01-1 and 2023-01-02 every hour.
let requestBuilder = new JhvRequestBuilder();
requestBuilder
  .SetTimeRange("2023-01-01 00:00:00", "2023-01-02 00:00:00")
  .SetCadence(3600)
  .AddSource("SDO", "AIA 304")
  .Build()
  .Send();

You can add multiple sources to the request:

let requestBuilder = new JhvRequestBuilder();
requestBuilder.SetTimeRange('2023-01-01 00:00:00', '2023-01-02 00:00:00')
    .SetCadence(3600)e
    .AddSource("SDO", "AIA 304")
    .AddSource("SOHO", "LASCO C2")
    .AddSource("SOHO", "LASCO C3")
    .Build().Send();

You can check if JHelioviewer is alive before making any requests

import { IsJhvRunning } from "jhvrequest";

// IsJhvRunning returns true/false
let isJhvRunning = await IsJhvRunning();
if (isJhvRunning) {
  // Send request
} else {
  // Jhv is not running
}

Nodejs vs Browser environments

The dependency sampjs currently only supports a browser environment because it depends on xmlhttprequest and parsing xml via the DOM. But you can get this to work in a nodejs environment with the xmlhttprequest and xmldom package by adding XMLHttpRequest to the the global variable and hooking the xmldom.DOMParser into XMLHttpRequest.prototype.responseXML.

See test/jhvrequest.test.ts as an example.

IsJhvRunning

async function checks if JHelioviewer is running and returns a boolean.

import { IsJhvRunning } from "jhvrequest";
// result is a true/false
let result = await IsJhvRunning();

JhvRequestBuilder

| Method | Description | | -------------------------------------------------- | -------------------------------------------------------------------------------------------- | | SetName(appName) | Sets the application name. This is the name which appears in the JHelioviewer request popup. | | SetTimeRange(start, end) | Set the time range to query. Start and end are strings to remove ambiguity with js dates | | SetCadence(seconds) | Set the time step to use between start and end. in seconds. | | AddSource(observatory, dataset, (Optional) server) | Add an image layer to the request. | | Build() | Construct a JhvRequest from the builder |

JhvRequest

| Method | Description | | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------- | | Send() | Send the request to JHelioviewer. This is an async operation and will complete after the user accepts or declines the request in JHelioviewer. |