htmlwidget

13 min

The htmlwidget object allows you to instantiate additional HTML browsers.

htmlwidget IDL

interface HtmlWidgetEvent {
    attribute String type;
    [optional] attribute String url;
};

callback HtmlWidgetEventCallback = void (HtmlWidgetEvent event);
[
    Constructor(HtmlWidgetParams params)
] interface HtmlWidget {
    void postMessage(Object data);
    void close();
    void raise();
    void lower();
    void addEventListener(String type, HtmlWidgetEventCallback callback);
    void removeEventListener(String type, HtmlWidgetEventCallback callback);
};
  
interface HtmlWidgetParams {
    attribute HtmlWidgetRect rect;
    attribute String url;
    [optional] attribute NodeParams node;
    [optional] attribute JavascriptInjection javascriptInjection;
    [optional] attribute bool bsObjects;
    [optional] attribute Storage storage;
    [optional] attribute String inspectorServer;
    [optional] attribute bool inputEnabled;
    [optional] attribute Security security;
    [optional] attribute String transform;
    [optional] attribute String hwzDefault;
    [optional] attribute bool interceptReloads;
};
  
interface HtmlWidgetRect {
    attribute long x;
    attribute long y;
    attribute long w;
    attribute long h;
};
  
interface NodeParams {
    attribute bool enabled;
    [optional] attribute Array<String> arguments;
};
  
interface JavascriptInjection {
    [optional] attribute JavascriptInjectionDetailList documentCreation;
    [optional] attribute JavascriptInjectionDetailList documentReady;
    [optional] attribute JavascriptInjectionDetailList deferred;
};
  
interface JavascriptInjectionDetail {
    [optional] attribute String world;
    [optional] attribute String source;
    [optional] attribute String uri;
    [optional] attribute String code;
};
  
interface Storage {
    attribute String path;
    attribute long quota;
    attribute bool forceSharedStorage;
    attribute bool forceUnsharedStorage;
};
  
interface Security {
    [optional] attribute bool insecureOriginEnabled;
    [optional] attribute bool cameraEnabled;
    [optional] attribute bool desktopCaptureEnabled;
    [optional] attribute bool audioCaptureEnabled;
    [optional] attribute bool insecureHttpsEnabled;
    [optional] attribute bool trustedIframesEnabled;
};

Object Creation

To create a htmlwidget object first load the brightsign/htmlwidget module using the require() method. Then create an instance of the htmlwidget class.

var HtmlWidgetClass = require("@brightsign/htmlwidget");
var htmlwidget = new HtmlWidgetClass({ rect:{x: 0, y:0, w: 640, h: 480 }, url: "https://brightsign.biz" });

HtmlWidgetEvent

Available as of BOS 9.0.168. See JavaScript Event HandlingJavaScript Event Handling

The cause of the event can be one of the following:

"load-started": The HTML widget has started loading a page.

"load-finished": The HTML widget completed loading a page.

"load-error": The HTML widget failed to load a page. Use the url key to identify the failing resource and the message key to retrieve some explanatory text.

HtmlWidget

postMessage()

void postMessage(Object data)

Sends an asynchronous message to the child browser process. If the child process has an @brightsign/messageport object open, this message will generate a "bsmessage" event on that object. The payload can be any JavaScript object but must be only one level deep (that is, it cannot include other nested objects).

close()

void close()

Shuts down the child browser process. This is equivalent to calling window.close() from inside the child browser. Node.js® parent processes won't exit automatically and the HTML widget can't be garbage collected until the widget is closed.

raise()

void raise()

Changes the stacking order of HTML widgets

lower()

void lower()

Changes the stacking order of HTML widgets

HtmlWidgetParams

This interface contains the HTML widget parameters.

rect HtmlWidgetRect: Contains the set parameters of the size and positioning of the widget.

url String: The URL to use for display.

node NodeParams optional: Contains the parameters used to specify added Node.js functionality.

javascriptInjection JavascriptInjection optional: Contains the parameters that specify JavaScript code to inject at different initialization points.

bsObjects bool optional: Enables or disables BrightScript-JavaScript Objects. This value is disabled by default.

storage Storage optional: Used to configure HTML storage.

inspectorServer String optional: Enables the Chromium Inspector, which allows you to debug JavaScript applications while a webpage is running. Starting in BOS 8.5.31 you will need to also set the enable_web_inspector registry key (in the "html" section) to enable the JavaScript console.

To access the console, navigate to the player IP address at the specified port number. See this page for documentation relating to the JavaScript console.

In “enable_web_inspector”, "1" will allow the inspector and "0" or not present will disable it. A reboot will be needed for these changes to take effect (if you enable/disable this through the LDWS UI, it may trigger a reboot to apply the change)

For security reasons, enable_web_inspector should only be used in non-production presentations. Make sure to disable JavaScript console before publishing to a production environment. In the Chromium version found in BOS 8.5.31 and beyond, the JavaScript console will log information in memory even when you are not connected to the inspector. This will consume memory until the player runs out, which will result in a crash.

inputEnabled bool optional: Enables mouse/touchscreen events. This value is false by default.

security Security optional: Override Chromium security checks.

transform String optional: Sets the screen orientation of content in the widget (note that the coordinates and dimensions of the roRectangle containing the widget are not affected by rotation). The following values are accepted:

"identity": There is no transform (i.e. the widget content is oriented as landscape). This is the default setting.

"rot90": The widget content is rotated to portrait at 90 degrees (clockwise).

"rot180": The widget content is rotated to portrait at 180 degrees (clockwise).

"rot270": The widget content is rotated to portrait at 270 degrees (clockwise).

hwzDefault String optional: Specifies the default HWZ Video behavior. This value is off by default. To enable it, set it to on.

interceptReloads bool optional: Prevents window.location.reload() or similar constructs from taking effect in the browser. Instead the parent will receive a reloadRequested event.

HtmlWidgetRect

This interface allows you to set the size and positioning of the widget rectangle.

x long: Specifies the x coordinate for the widget.

y long: Specifies the y coordinate for the widget.

w long: Sets the width of the widget in pixels.

h long: Sets the height of the widget in pixels.

NodeParams

This interface allows you to enable Node.js and define the parameters of the Node.js command-line arguments.

enabled bool: Enables Node.js on the widget. The value is false by default.

arguments Array optional: An array specifying command-line arguments.

JavascriptInjection

Use this interface to inject user scripts into the JavaScript engine.

documentCreation JavascriptInjectionDetailList optional: The script will run as soon as the document is created. This behavior is not suitable for any DOM operation.

documentReady JavascriptInjectionDetailList optional: The script will run as soon as the DOM is ready. This behavior is equivalent to the DOMContentLoaded event firing in JavaScript.

deferred JavascriptInjectionDetailList optional: The script will run when the page load finishes.

JavascriptInjectionDetail

This interface defines the user scripts that are used by the JavascriptInjection interface. Exactly one of the source, uri, or code fields must be defined.

world String optional: Isolates user scripts into different worlds. This string can be assigned one of the following values: application, user, or main (see this page for more details); if the world parameter is not included in the array, "application" is selected by default.

source String optional: Deprecated. Use uri or code instead.

uri String optional: If defined, this must contain either a "file" URI, or a "data" URI with one of the following supported formats:

"data:text/javascript;charset=utf-8;"

"data:text/javascript;charset=utf-8;base64,"

"data:text/javascript;charset=us-ascii;"

"data:text/javascript;charset=us-ascii;base64,"

code String optional: If defined, the content will be executed as JavaScript code.

Storage

This interface allows you to define the following HTML storage parameters:

path String: The folder used by local storage applications such as the JavaScript storage class.

quota long: The size (in bytes) allotted to all local storage applications (including IndexedDB). If the storage path is specified without a storage quota, Chromium defaults to reserving 1GB plus 10% of the total size of the storage device.

forceSharedStorage bool: Allows HTTP/HTTPS loaded URLs to share local storage if they are loaded from the same domain.

forceUnsharedStorage bool: Prevents file loaded URLs from sharing storage.

Data can be corrupted if two HTML widgets access the database at the same time, but some applications rely on this type of access. Use the force_unshared_storage flag to avoid sharing on local URLs if you experience data problems, or use the force_shared_storage flag to allow sharing on HTTP/HTTPS sites. (If both flags are set, file storage is separated and HTTP storage is not.)

Security

Overrides Chromium security checks for these parameters:

insecureOriginEnabled bool optional: Ignore insecure origins and treat them as enabled.

cameraEnabled bool optional: Enables webpage access to USB cameras connected to the player (access is disabled by default). This allows support for WebRTC applications.

desktopCaptureEnabled bool optional: Enables desktop capture.

audioCaptureEnabled bool optional: Enables audio capture.

insecureHttpsEnabled bool optional: Ignore security errors when connecting to insecure HTTPS hosts (insecure HTTPS is disabled by default). Enabling this feature makes the player insecure; it is not suitable for production environments and should only be used for testing.

trustedIframesEnabled bool optional: Controls if content loaded in iframes is permitted access to Node.js and BrightSign-JavaScript objects. This flag will be available for BOS versions 9.1.75.3 and later. It will result as a failure to load HTML widget if used in earlier versions.

To enable Node in iframes, initialize enabled and trustedIframesEnabled to be true.

To enable BrightSign-JavaScript objects in iframes, initialize bsObjects and trustedIframesEnabled to be true.

With BOS 8.2 and later (Chromium69 and later), several new CORS checks have been added. security_params.websecurity or enableSecurity(false) do not disable all these checks. Use the following registry setting instead:

registry write html disable-web-security 1

This flag will take effect on all htmlwidget instances, as opposed to previous flags which are only effective on the instance they are called on.

To write this to the registry using roRegistrySectionroRegistrySection:

RegHtml = CreateObject("roRegistrySection", "html")
RegHtml.Write("disable-web-security", "1")
RegHtml.Flush()