Query and download attachments — query_layer

Get metadata about attachments associated with features in a layer. Query attachment information using query_layer_attachments() and download attachments using download_attachments().

Usage

query_layer_attachments(
  x,
  definition_expression = "1=1",
  attachments_definition_expression = NULL,
  object_ids = NULL,
  global_ids = NULL,
  attachment_types = NULL,
  keywords = NULL,
  ...,
  token = arc_token()
)

download_attachments(
  attachments,
  out_dir,
  ...,
  overwrite = FALSE,
  .progress = TRUE,
  token = arc_token()
)

Arguments

x: an object of class FeatureLayer, Table, or ImageServer.
definition_expression: default 1 = 1. A SQL where clause that is applied to the layer. Only those records that conform to this expression will be returned. This parameter is required if neither object_ids or global_ids have been defined.
attachments_definition_expression: default NULL. A SQL where calsue that is applied to the attachment metadata. only attachments that conform to this expression will be returned.
object_ids: mutually exclusive with definition_expression and global_ids. The object IDs of the features to query attachments of.
global_ids: mutally exclusive with definition_expression and object_ids. The global IDs of the features to query attachments of.
attachment_types: default NULL. A character vector of attachment types to filter on.
keywords: default NULL. A character vector of the keywords to filter on.
...: unused
token: your authorization token.
attachments: a data.frame created by query_layer_attachments(). Must contain the columns name, url, and contentType.
out_dir: the path to the folder to download the file
overwrite: default FALSE. A
.progress: default TRUE. Whether a progress bar should be provided.

Value

query_layer_attachments() returns a data.frame.

download_attachments() returns a list. If an error occurs, the condition is captured and returned in the list. Otherwise the path to the file that was downloaded is returned.

References

ArcGIS REST API Documentation

Examples

if (FALSE) {
# create a url path that isn't too wide for CRAN
furl <- paste(
  c(
    "https://services1.arcgis.com/hLJbHVT9ZrDIzK0I",
    "arcgis/rest/services/v8_Wide_Area_Search_Form_Feature_Layer___a2fe9c",
    "FeatureServer/0"
  ),
  collapse = "/"
)
# connect to the layer
layer <- arc_open(furl)

# get the attachment info
att <- query_layer_attachments(layer)

# download them to a path
download_attachments(att, "layer_attachments")
}