Count matching elements

pz_get_count() returns the number of elements matching target, counted inside the current scope. Unlike the other getters it doesn't wait for a match: 0 is a valid answer, so it resolves once and returns immediately. One exception: on a scope whose pinned elements have left the page it raises paparazzi_error_detached instead of returning 0, because the pinned set promises a live set and is never silently re-queried.

Usage

pz_get_count(ctx, target = NULL, ...)

Arguments

ctx

A paparazzi context.

target

A CSS selector string, a pz_loc() spec, or a list of specs and strings (a union matching any of them). NULL means the current context: the pinned set at a scoped context, whose count comes back without a re-query, or the page body at the root.

...

Checked empty; reserved for future use.

Value

An integer.

Examples

page <- pz_open(pz_example("tasks"))
pz_get_count(page, target = ".task")
#> [1] 7

# Zero is an answer, so pz_get_count() never waits
pz_get_count(page, target = ".error-message")
#> [1] 0

# Counts are relative to the current scope
page |>
  pz_find(".task-list") |>
  pz_get_count(target = ".task.done")
#> [1] 1
pz_close(page)