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Static functions

Source: R/static-funs.R
static_functions.Rd

These functions provide support to work with static catalogs.

  • stac_read(): open a STAC document from an URL.

  • read_items(): opens (statically) all items referred in links key entry of a given collection document (doc_collection).

  • links(): extracts and filters the links of any STAC document.

  • link_open(): opens (statically) the document referenced by the link. This function can resolve any relative URL.

Usage

read_stac(url, ...)

read_items(collection, ..., limit = 100, page = 1, progress = TRUE)

read_collections(catalog, ..., limit = 100, page = 1, progress = TRUE)

links(x, ...)

link_open(link, base_url = NULL)

Arguments

url

a character value with the URL to a valid STAC document.

...

additional arguments. See details.

collection

a doc_collection object to fetch all rel=="item" links.

limit

an integer with defining the page size of items to fetch.

page

an integer with the page number to fetch the items.

progress

a logical indicating if a progress bar must be shown or not. Defaults to TRUE.

catalog

a doc_catalog object to fetch all rel=="child" links.

x

any rstac document with 'links' key entry.

a doc_link object, usually an element of links key entry.

base_url

a character with the base URL to resolve relative links. If NULL (default) rstac will try resolve relative links using internal metadata.

Value

  • links(): a doc_links object containing a list of link entries.

  • link_open(): a recognizable rstac document.

Details

Ellipsis argument (...) may appears in different items functions and has distinct purposes:

  • stac_read(): ellipsis is used to pass any additional parameters to read_json function.

  • links(): ellipsis is used to pass logical expressions to be evaluated against a doc_link item as a filter criteria. See examples.

Examples

if (FALSE) { # \dontrun{
 x <- stac("https://brazildatacube.dpi.inpe.br/stac") %>%
     collections("CB4-16D-2") %>%
     get_request()

 link <- links(x, rel == "items")
 link_open(link[[1]])
} # }

if (FALSE) { # \dontrun{
 wv_url <- paste0(
   "https://s3.eu-central-1.wasabisys.com",
   "/stac/openlandmap/wv_mcd19a2v061.seasconv/collection.json"
 )
 wv <- read_stac(wv_url)
 stac_type(wv)  # Collection

 # reads the second page of 5 links
 wv_items <- read_items(wv, limit = 5, page = 2)

 # lists all links of the collection document that are not items
 links(wv, rel != "item")

 # lists all links of the items document
 links(wv_items)
} # }