PureBasic WebGadget — Domains

Overview

The Chromium Framework currently integrates 11 domains, covering 196 commands from the Chrome DevTools Protocol (CDP). While only a subset of the full protocol is implemented, developers can invoke any domain or method by calling the following alternative Procedure:

Cr_WebSocket_Command(Connection, EventID, Method.s, Params.s = #Null$)

Each command requires a Connection, an Event ID, and a Method. The Parameters argument is optional and defaults to #Null$ if omitted.

• Event ID — any user-defined number (predefined constants are also available).
• Method — composed of the domain name followed by a period and the command name.
• Parameters — specified as a JSON string, allowing a mix of data types.

Example Code:

Params$ = #DQUOTE$ + "features" + #DQUOTE$ + ":[{" +
          #DQUOTE$ + "name" + #DQUOTE$ + ":" + #DQUOTE$ + "prefers-color-scheme" + #DQUOTE$ + "," +
          #DQUOTE$ + "value" + #DQUOTE$ + ":" + #DQUOTE$ + "light" + #DQUOTE$ +
          "}]"
Cr_WebSocket_Command(Connection, 123456, "Emulation.setEmulatedMedia", Params$)

Browser Domain (12)

Commands for interacting with browser-level features such as permissions, windows, and downloads.

CSS Domain (38)

Read and write CSS stylesheets, rules, and styles, and track computed style updates.

DOM Domain (27)

Access and manipulate the document structure of a webpage.

Emulation Domain (19)

Simulate device and environmental conditions such as screen size and geolocation.

Fetch Domain (8)

Manage network requests, authentication challenges, and response handling.

Input Domain (7)

Simulate user input such as keyboard events, mouse interactions, and text entry.

Network Domain (14)

Control caching, cookies, headers, and user-agent behavior.

Overlay Domain (24)

Highlight, display, or hide elements on a web page for debugging and visual inspection.

Page Domain (26)

Comprehensive commands for page lifecycle, rendering, navigation, and scripting operations.

Runtime Domain (17)

Execute and manage JavaScript code, bindings, and scripts within the target environment.

Target Domain (12)

Attach to, manage, or control different browser targets such as tabs or extensions.

Command Usage

Executing a command from a specific domain is generally simpler than using the Cr_WebSocket_Command() procedure directly. Each command mirrors the method name, with the domain and command separated by an underscore.

• Commands include required parameters entered using the actual data types.
• Optional parameters can be defined using a structured List in PureBasic.

Without Optional Parameters:

Page_CaptureScreenshot(Connection, #UE_Page_CaptureScreenshot)

With Optional Parameters:

NewList params_data.PARAMS_DATA()
AddElement(params_data())
params_data()\Name = "clip"
params_data()\Type = #Cr_DataType_Object
params_data()\Input = "{" +
                       #DQUOTE$ + "x" + #DQUOTE$ + ":0," +
                       #DQUOTE$ + "y" + #DQUOTE$ + ":0," +
                       #DQUOTE$ + "width" + #DQUOTE$ + ":" + Str(Width) + "," +
                       #DQUOTE$ + "height" + #DQUOTE$ + ":" + Str(Height) + "," +
                       #DQUOTE$ + "scale" + #DQUOTE$ + ":" + StrF(Scale, 2) +
                       "}"
AddElement(params_data())
params_data()\Name = "captureBeyondViewport"
params_data()\Type = #Cr_DataType_Boolean
params_data()\Input = "true"
Page_CaptureScreenshot(Connection, #UE_Page_CaptureScreenshot, params_data())