Applet Resources

Often there are some JavaScripts and CSS styles necessary to be loaded for your Applet. It can be libraries like jQuery or even your whole application code. For these necessities offline API for saving, storing & loading files are ready.

Methods	Description	Supported since
addFile()	Add single file to Applet before starting it.	1.0.0
addFiles()	Add files to Applet before starting it.	1.0.0
addFilesSync()	Add files to Applet before starting it in the set order to prevent race condition.	1.0.0

File object

Every method above, accept single object or array of objects depending by type. Every object must have these keys.

Key	Type	Required	Description
uri	String	Yes	URL of file
uid	String	Yes	Unique ID in Applet for future manage
type	String	Yes	Type of file. Example: sos.offline.types.javascript, sos.offline.types.css, sos.offline.types.video
			^^
flags	Array	Yes	Special flag for file
headers	Array	No	Authorization headers

info

• The file URL must point to a file. If your URI leads to a 303 redirect (e.g. from http to https), the API will not work.
• There are some limitations for Emulator.

addFile()

Method addFile() will allow you to load single resource into applet. If you want to load more resource, use addFiles().

Javascript Example

const file = { // File that will be loaded into an applet
    "uri": "https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js",
    "uid": "jquery-2.2.4.min.js",
    "type": sos.offline.types.javascript,
    "flags": [sos.offline.flags.append(document.body)]
}

await sos.offline.addFile(file); // And finally load file

addFiles()

Method addFiles() will allow you to load array of your resources into Applet. Files are load in random order.

Javascript Example

const files = [ // Array of files
	{
		"uri": "https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js",
		"uid": "jquery-2.2.4.min.js",
		"type": sos.offline.types.javascript,
		"flags": [sos.offline.flags.append(document.body)]
	},
	{
		"uri": "https://signageostest.blob.core.windows.net/test/applet-examples/benchmark-styles.css?v=1.0.0",
		"uid": "benchmark-styles.css-v1.0.0",
		"type": sos.offline.types.css,
		"headers": { "Authorization": "Basic Zm9vOmJhcg==" },
		"flags": [sos.offline.flags.append(document.head)]
	}
];

await sos.offline.addFiles(files);

GitHub Example

Example of Applet that save files and load them in one file

addFilesSync()

Method addFilesSync() works same as method above, but all files are loaded in correct order. Otherwise, files are loaded in random order by file size.

Javascript example

const files = [
	{
		"uri": "https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js",
		"uid": "jquery-2.2.4.min.js",
		"type": sos.offline.types.javascript,
		"flags": [sos.offline.flags.append(document.body)]
	},
	{
		"uri": "https://signageostest.blob.core.windows.net/test/applet-examples/benchmark-styles.css?v=1.0.0",
		"uid": "benchmark-styles.css-v1.0.0",
		"type": sos.offline.types.css,
		"headers": { "Authorization": "Basic Zm9vOmJhcg==" },
		"flags": [sos.offline.flags.append(document.head)]
	}
];

sos.offline.addFilesSync(files).then(() => {
	console.log('Now you can use jQuery and CSS file');
	jQuery('#do').something();
});

Usage with Typescript

You can also use all these methods with signageOS TypeScript.

interface ISaveFile {
	uid: string;
	uri: string;
	type: string;
	headers?: { [key: string]: string };
	flags?: IFlag[];
}

addFile(files: ISaveFile[]): Promise<void>;
addFiles(files: ISaveFile[]): Promise<void>;
addFilesSync(files: ISaveFile[]): Promise<void>;

Flags that can be optionally passed to the file object are available in flags property.

interface IFlag {
	type: 'append';
	element: IElement;
}

Errors

Although we are doing our best, following errors may occur when working with the Applet Resources.

Code	Type	Message
40101	AppletResourcesError	File needs to be object
40102	AppletResourcesError	File UID needs to be defined
40103	AppletResourcesError	File flags needs to be Array
40104	AppletResourcesError	File flag needs to be object
40105	AppletResourcesError	Already loading file: FILE_NAME
^^	^^	Your code has probably multiple occurrences of addFile/s methods.
40106	AppletResourcesError	Already existing file: FILE_NAME
^^	^^	File is already loaded or exists in Applet
49901	FileNotFoundError	File FILE_ID was not found
^^	^^	Applet can not get file. URL is invalid.