Package 'hdar'

Title: 'REST' API Client for Accessing Data on 'WEkEO HDA V2'
Description: Provides seamless access to the WEkEO Harmonised Data Access (HDA) API, enabling users to query, download, and process data efficiently from the HDA platform. With 'hdar', researchers and data scientists can integrate the extensive HDA datasets into their R workflows, enhancing their data analysis capabilities. Comprehensive information on the API functionality and usage is available at <https://gateway.prod.wekeo2.eu/hda-broker/docs>.
Authors: Matteo Mattiuzzi [aut, cre]
Maintainer: Matteo Mattiuzzi <[email protected]>
License: EUPL (>= 1.2)
Version: 1.0.4
Built: 2025-03-13 13:48:20 UTC
Source: https://github.com/eea/hdar

Help Index

Auth Class

Description

Authorization

Methods

Public methods

Method new()

This function initializes a new instance of the 'Auth' class with the specified parameters.

Usage
Auth$new(user = NULL, password = NULL)
Arguments
user

A character string representing the username for authentication.

password

A character string representing the password for authentication.

Returns

An instance of the 'Auth' class.

Method token()

This function retrieves a previously generated token.

Usage
Auth$token()
Returns

A character string representing the retrieved token.

Method get_token()

This function generates a unique token for authentication or other purposes.

Usage
Auth$get_token()
Returns

A character string representing the generated token.

Method clone()

The objects of this class are cloneable with this method.

Usage
Auth$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

Client Class

Description

The Client is the central gateway for interfacing with the HDA Service. It provides a comprehensive suite of methods to perform operations and retrieve data from the service efficiently.

Public fields

apiUrl

API endpoint

Methods

Public methods

Method new()

Constructor for the 'Client' class. Initializes a new instance with authentication credentials.

Usage
Client$new(user, password, save_credentials = FALSE)
Arguments
user

Character string representing the username for authentication.

password

Character string representing the password for authentication.

save_credentials

A logical value indicating whether to save the credentials to a configuration file. Default is FALSE.

Returns

An instance of the 'Client' class.

Method token()

Retrieves the current authentication token.

Usage
Client$token()
Returns

Character string representing the authentication token.

Method get_token()

Generates a new authentication token.

Usage
Client$get_token()
Returns

Character string representing the newly generated token.

Method send_request()

Sends a specified request to the server and returns the response.

Usage
Client$send_request(req, raw_response = FALSE)
Arguments
req

A request object or list representing the HTTP request.

raw_response

Optional logical value indicating whether the raw response should be returned instead of the parsed body.

Returns

A response object containing the server's response.

Method show_terms()

This function displays the terms and conditions for the services.

Usage
Client$show_terms()
Returns

An HTML document containing the terms and conditions in a collapsible format.

Method terms_and_conditions()

Function to retrieve and accept terms and conditions. Accepting T&C is permanent, it is enough to run this function one. To read T&C see show_terms.

Usage
Client$terms_and_conditions(term_id, reject = FALSE)
Arguments
term_id

A character vector of term_ids that you wish to accept. If missing current status is returned. Use "all" if you want to accept all terms at once.

reject

Logical, default 'FALSE'. If TRUE it inverts the operation and the provided term_id's are rejected/revoked.

Returns

A data frame reflecting the actual acceptance status for each term.

Method datasets()

Lists datasets available on WEkEO, optionally filtered by a text pattern.

Usage
Client$datasets(pattern = NULL)
Arguments
pattern

Optional character string to filter dataset names by matching text.

Returns

List containing datasets and associated information.

Method search()

This function performs a search based on a specified query and returns an instance of SearchResults.

Usage
Client$search(json_query, limit = NULL)
Arguments
json_query

Character string representing the search query.

limit

Optional; a number specifying the maximum number of results to return.

Returns

An instance of the SearchResults class containing the search results.

Method get_querytemplate()

Retrieves the raw query metadata for a specified datasetId.

Usage
Client$get_querytemplate(datasetId, to_json = FALSE)
Arguments
datasetId

Character, representing the dataset's identifier.

to_json

Logical; if 'TRUE', returns the data in JSON format.

Returns

List or JSON file containing the raw query options.

Method generate_query_template()

This function generates a query template based on a specified datasetId.

Usage
Client$generate_query_template(datasetId)
Arguments
datasetId

A numeric or character ID representing the dataset.

Returns

A JSON representing the generated query template.

Method clone()

The objects of this class are cloneable with this method.

Usage
Client$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

Note

There are some inconsistencies between the return of 'GET querymetadata' and what must be submitted to the HDA. Use generate_query_template to resolve these inconsistencies.

See Also

show_terms to read the Terms and conditions.

SearchResults for details on the returned object.

SearchResults Class

Description

This class handles the storage and manipulation of search results including downloading resources based on a search query.

SearchResults

Public fields

results

Stores the search results data.

total_count

Stores the total count of results' element.

total_size

Stores the total size of results

Methods

Public methods

Method new()

Initializes a new SearchResults object with the specified client, results, and dataset identifier.

Usage
SearchResults$new(client, results, dataset_id)
Arguments
client

An object containing the API client used to interact with the dataset.

results

List containing search results.

dataset_id

The identifier for the dataset being queried.

Returns

SearchResult instance

Method download()

Downloads resources based on stored results or selected indices of results.

Usage
SearchResults$download(
  output_dir,
  selected_indexes,
  stop_at_failure = TRUE,
  force = FALSE
)
Arguments
output_dir

A string specifying the directory where downloaded files will be saved.

selected_indexes

Optional; indices of the specific results to download.

stop_at_failure

Optional; controls whether the download process of multiple files should immediately stop upon encountering the first failure.

force

Optional; forces the download even if the file already exists in the specified output directory.

Returns

Nothing returned but downloaded files are saved at the specified location.

Method clone()

The objects of this class are cloneable with this method.

Usage
SearchResults$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.