req_template: Set request method/path from a template

In r-lib/httr2: Perform HTTP Requests and Process the Responses

Set request method/path from a template

Description

Many APIs document their methods with a lightweight template mechanism that looks like GET /user/{user} or ⁠POST /organisation/:org⁠. This function makes it easy to copy and paste such snippets and retrieve template variables either from function arguments or the current environment.

req_template() will append to the existing path so that you can set a base url in the initial request(). This means that you'll generally want to avoid multiple req_template() calls on the same request.

Usage

req_template(req, template, ..., .env = parent.frame())

Arguments

req	A httr2 request object.
template	A template string which consists of a optional HTTP method and a path containing variables labelled like either ⁠:foo⁠ or {foo}.
...	Template variables.
.env	Environment in which to look for template variables not found in .... Expert use only.

Value

A modified HTTP request.

Examples

httpbin <- request(example_url())

# You can supply template parameters in `...`
httpbin |> req_template("GET /bytes/{n}", n = 100)

# or you retrieve from the current environment
n <- 200
httpbin |> req_template("GET /bytes/{n}")

# Existing path is preserved:
httpbin_test <- request(example_url()) |> req_url_path("/test")
name <- "id"
value <- "a3fWa"
httpbin_test |> req_template("GET /set/{name}/{value}")

r-lib/httr2 documentation built on Jan. 11, 2025, 10:21 a.m.