Implementation:MarketSquare Robotframework browser Browser Init

Property	Value
Implementation Name	Browser Init
Type	API Doc
Domains	Test_Automation, Configuration
Workflow	Browser_Test_Authoring
Repository	MarketSquare/robotframework-browser

Overview

Concrete tool for configuring the Browser library at import time provided by robotframework-browser.

Description

The Browser.__init__ method is the constructor of the Browser library class. When Robot Framework processes a Library Browser statement in a suite's Settings section, it instantiates the Browser class and passes any keyword arguments to this constructor. The constructor accepts keyword-only arguments (no positional arguments are allowed) that establish global defaults for the entire test execution session.

Key responsibilities of the constructor:

Initializes internal component libraries (PlaywrightState, Control, Interaction, Getters, Promises, Waiter, etc.)
Creates a SettingsStack for each configurable parameter (timeout, retry_assertions_for, strict_mode, run_on_failure, selector_prefix, etc.)
Configures Playwright debug logging behavior
Loads optional JavaScript extensions and Python plugins
Sets up the presenter mode for visual debugging
Registers the library as its own Robot Framework listener for lifecycle events

Usage

Use this API when importing the Browser library in a Robot Framework suite file. All parameters are optional and have sensible defaults. Configuration is typically done once per project in a resource file or suite initialization file.

Code Reference

Source Location

Repository: robotframework-browser
File: Browser/browser.py (Lines 796-939)

Signature

def __init__(
    self,
    *_,
    auto_closing_level: AutoClosingLevel = AutoClosingLevel.TEST,
    auto_delete_passed_tracing: bool = False,
    enable_playwright_debug: PlaywrightLogTypes | bool = PlaywrightLogTypes.library,
    enable_presenter_mode: HighLightElement | bool = False,
    external_browser_executable: dict[SupportedBrowsers, str] | None = None,
    highlight_on_failure: bool = False,
    jsextension: list[str] | str | None = None,
    language: str | None = None,
    playwright_process_host: str | None = None,
    playwright_process_port: int | None = None,
    plugins: list[str] | str | None = None,
    retry_assertions_for: timedelta = timedelta(seconds=1),
    run_on_failure: str = "Take Screenshot  fail-screenshot-{index}",
    selector_prefix: str | None = None,
    show_keyword_call_banner: bool | None = None,
    strict: bool = True,
    timeout: timedelta = timedelta(seconds=10),
    tracing_group_mode: TracingGroupMode = TracingGroupMode.Full,
) -> None

Import

# Python import
from Browser import Browser

# Robot Framework import (in *** Settings ***)
# Library    Browser

I/O Contract

Parameter	Type	Default	Description
`auto_closing_level`	AutoClosingLevel	TEST	Configure automatic closing of contexts and pages. Options: TEST, SUITE, MANUAL.
`auto_delete_passed_tracing`	bool	False	If True, traces of passed tests are not saved when auto_closing_level is SUITE or TEST.
`enable_playwright_debug`	PlaywrightLogTypes or bool	PlaywrightLogTypes.library	Enable low-level Playwright debug logging. True enables playwright-level logs; False uses library-level only.
`enable_presenter_mode`	HighLightElement or bool	False	Highlights interacted elements with configurable duration, width, style, and color.
`external_browser_executable`	dict or None	None	Maps browser type to custom executable path (currently only chromium supported).
`highlight_on_failure`	bool	False	If True, highlights the failing element in failure screenshots.
`jsextension`	list[str] or str or None	None	Path(s) to CommonJS modules exposed as extra keywords.
`language`	str or None	None	Language code for translating keyword names and documentation.
`plugins`	list[str] or str or None	None	External Python classes that extend the Browser library.
`retry_assertions_for`	timedelta	1 second	How long assertion keywords retry polling after the first failure.
`run_on_failure`	str	"Take Screenshot fail-screenshot-{index}"	Keyword to execute automatically when any Browser keyword fails.
`selector_prefix`	str or None	None	Prefix prepended to all selectors (useful for iframe-prefixed selectors).
`show_keyword_call_banner`	bool or None	None	Show a banner with keyword name at page bottom. None means only with presenter mode.
`strict`	bool	True	If True, selectors matching multiple elements cause keyword failure.
`timeout`	timedelta	10 seconds	Default timeout for element-based keyword operations.
`tracing_group_mode`	TracingGroupMode	Full	How Robot Framework keyword calls are logged in Playwright trace. Options: Full, Stack.

Returns	Description
None	The constructor does not return a value. The library instance is registered with Robot Framework.

Usage Examples

*** Settings ***
Library    Browser    timeout=30s    retry_assertions_for=5s    strict=True

*** Test Cases ***
Example With Default Config
    New Page    https://example.com
    Get Title    ==    Example Domain

*** Settings ***
# Full configuration example
Library    Browser
...    timeout=15s
...    retry_assertions_for=3s
...    strict=True
...    auto_closing_level=TEST
...    run_on_failure=Take Screenshot  failure-{index}  fullPage=True
...    enable_presenter_mode=False
...    highlight_on_failure=True

*** Settings ***
# Headless CI configuration with minimal timeout
Library    Browser    timeout=5s    run_on_failure=NONE

*** Settings ***
# Using plugins and JavaScript extensions
Library    Browser
...    plugins=my_plugin.MyPlugin
...    jsextension=my_custom_keywords.js

Related Pages

Implements Principle

Principle:MarketSquare_Robotframework_browser_Library_Import_and_Configuration

Requires Environment

Uses Heuristic

Heuristic:MarketSquare_Robotframework_browser_Shared_Node_Process_For_Parallel

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Implementation

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