Simulate a session in web browser

This set of functions allows you to simulate a user interacting with a website, using forms and navigating from page to page.

• Create a session with session(url)

• Navigate to a specified url with session_jump_to(), or follow a link on the page with session_follow_link().

• Submit an html_form with session_submit().

• View the history with session_history() and navigate back and forward with session_back() and session_forward().

• Extract page contents with html_element() and html_elements(), or get the complete HTML document with read_html().

• Inspect the HTTP response with httr::cookies(), httr::headers(), and httr::status_code().

session() works with the static HTML returned by the server, so it is fast and has no external dependencies. Use read_html_live() instead if the page is dynamically generated with javascript, or if you need interactions that a real browser provides, like clicking buttons that run javascript or scrolling to load more content.

Usage

session(url, ...)

is.session(x)

session_jump_to(x, url, ...)

session_follow_link(x, i, css, xpath, ...)

session_back(x)

session_forward(x)

session_history(x)

session_submit(x, form, submit = NULL, ...)

Arguments

url

A URL, either relative or absolute, to navigate to.

...

Any additional httr config to use throughout the session.

x

A session.

i

A integer to select the ith link or a string to match the first link containing that text (case sensitive).

css, xpath

Elements to select. Supply one of css or xpath depending on whether you want to use a CSS selector or XPath 1.0 expression.

form

An html_form to submit

submit

Which button should be used to submit the form?

• NULL, the default, uses the first button.

• A string selects a button by its name.

• A number selects a button using its relative position.

• FALSE submits the form without any button. This is useful for forms that are submitted by JavaScript when a field changes.

Examples

s <- session("http://hadley.nz")
s |>
  session_jump_to("hadley.jpg") |>
  session_jump_to("/") |>
  session_history()
#>   https://hadley.nz/
#>   https://hadley.nz/hadley.jpg
#> - https://hadley.nz/

s |>
  session_jump_to("hadley.jpg") |>
  session_back() |>
  session_history()
#> - https://hadley.nz/
#>   https://hadley.nz/hadley.jpg

# \donttest{
s |>
  session_follow_link(css = "p a") |>
  html_elements("p")
#> Navigating to <https://posit.co>.
#> {xml_nodeset (14)}
#>  [1] <p class="mb-4 eyebrow dark:!text-white">Trusted by about 1 in  ...
#>  [2] <p>The enterprise platform for the AI era, giving data teams sp ...
#>  [3] <p>Generative AI makes it easy to produce a plausible-looking a ...
#>  [4] <p>Move from question to insight to analysis, model or applicat ...
#>  [5] <p>Introducing an entirely new way to work with data. Posit AI  ...
#>  [6] <p class="eyebrow mb-6">\n            <span>Results</span>\n\n  ...
#>  [7] <p>From faster insights to reduced risk, Posit customers achiev ...
#>  [8] <p dir="ltr"><span>Faster "what-if" analysis delivery at NASA</ ...
#>  [9] <p><span>Reduction in recordable incident rate at Suffolk Const ...
#> [10] <p>Savings on cloud infrastructure costs at TruDiagnostic<br> </p>
#> [11] <p class="eyebrow text-center mb-4 text-blue-300 dark:text-whit ...
#> [12] <p class="eyebrow !text-white mb-18">\n\t\t\t\t\t<span>Our miss ...
#> [13] <p>As a Public Benefit Corporation, we're committed to open sou ...
#> [14] <p class="address" translate="no"><span class="address-line1">2 ...
# }