R: Compute caching information for a response.

cache_info {httr} | R Documentation

## Compute caching information for a response.

### Description

`cache_info()` gives details of cacheability of a response, `rerequest()` re-performs the original request doing as little work as possible (if not expired, returns response as is, or performs revalidation if Etag or Last-Modified headers are present).

### Usage

    cache_info(r)

    rerequest(r)

### Arguments

`r` | A response

### Examples

    # Never cached, always causes redownload
    r1 <- GET("https://www.google.com")
    cache_info(r1)
    r1$date
    rerequest(r1)$date

    # Expires in a year
    r2 <- GET("https://www.google.com/images/srpr/logo11w.png")
    cache_info(r2)
    r2$date
    rerequest(r2)$date

    # Has last-modified and etag, so does revalidation
    r3 <- GET("http://httpbin.org/cache")
    cache_info(r3)
    r3$date
    rerequest(r3)$date

    # Expires after 5 seconds
    ## Not run:
    r4 <- GET("http://httpbin.org/cache/5")
    cache_info(r4)
    r4$date
    rerequest(r4)$date
    Sys.sleep(5)
    cache_info(r4)
    rerequest(r4)$date

    ## End(Not run)

[Package httr version 1.2.1 Index]