Initialization Control
The following static methods and properties help to set up the runtime environment for the library.
engineResourcePath
Specifies the path to find the engine(s). The property needs to be set before loadWasm. If not specified, the library will try to find the engine in the same location as the main JavaScript file (dbr.js).
static engineResourcePath: string
Code Snippet
Dynamsoft.DBR.BarcodeReader.engineResourcePath = "https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@9.6.42/dist/";
await Dynamsoft.DBR.BarcodeReader.loadWasm();
loadWasm
Downloads and compiles the engine to get it loaded/ready for a BarcodeReader
or BarcodeScanner
instance to be created. You can call this API to silently set the operating environment of the library as soon as the page is loaded, avoiding unnecessary waiting time when using the library later.
If this API is not called beforehand, it will be called automatically when creating an instance of BarcodeReader
or BarcodeScanner
.
static loadWasm(): Promise<void>
Return Value
A promise that resolves when the operation succeeds.
Code Snippet
window.addEventListener('DOMContentLoaded', (event) => {
Dynamsoft.DBR.BarcodeReader.loadWasm();
});
** Tips and Tricks **
isWasmLoaded
Returns whether the engine is loaded/ready.
static isWasmLoaded(): boolean
version
Returns the version of the library including the detailed version numbers of the engine and the main JavaScript code.
The engine version is only valid after loadWasm has been called.
readonly static version: string
Code Snippet
console.log(Dynamsoft.DBR.BarcodeReader.version);
// loading...(JS 8.8.3.20211011)
await Dynamsoft.DBR.BarcodeReader.loadWasm();
console.log("When loaded..." + Dynamsoft.DBR.BarcodeReader.version);
// 8.8.0.10403(JS 8.8.3.20211011)
detectEnvironment
Detects the current running environment and returns a report.
static detectEnvironment(): Promise<any>
Return value
A promise resolving to an object which contains some information of the current running environment.
Code Snippet
console.log(await Dynamsoft.DBR.BarcodeReader.detectEnvironment());
// {"wasm":true, "worker":true, "getUserMedia":true, "camera":true,
// "browser":"Chrome", "version":90, "OS":"Windows"}
onWarning
A callback which is triggered when the running environment is not ideal. In this version, it may get triggered in two scenarios:
- If the page is opened from the disk
- The page is hosted in a HTTP site without SSL
In both cases, the following warning is returned:
{
id: 2,
message: "Not connected via SSL (HTTPS), the SDK may not work correctly."
}
Code Snippet
Dynamsoft.DBR.BarcodeScanner.onWarning = warning => console.log(warning.message);
See Also