fetch_ogc_api_mml: Fetch Data from OGC API (Internal)

In geofi: Access Finnish Geospatial Data

Fetch Data from OGC API (Internal)

Description

This internal function retrieves spatial data from an OGC API endpoint with pagination support. It handles both limited and unlimited requests, automatically paginating through results when no limit is specified. It includes basic error handling and rate limit handling.

Usage

fetch_ogc_api_mml(api_url, limitti = NULL, max_pages = 100)

Arguments

api_url	Character. The base URL of the OGC API endpoint.
limitti	Numeric or NULL. The maximum number of features to retrieve per request. If NULL, the function first attempts to fetch all available features without pagination (limit=-1) for speed, falling back to pagination with a default limit of 10,000 per request if the no-paging request fails.
max_pages	Numeric. The maximum number of pages to fetch during pagination when limitti is NULL. Defaults to 100. Increase this value for very large datasets, but be cautious of long runtimes.

Details

This function is intended for internal use within the package. It uses the httr2 package to make HTTP requests and sf to parse GeoJSON responses into spatial data. When limitti is NULL, it first attempts to fetch all features in a single request (limit=-1). If this fails (e.g., due to R's character string size limit), it falls back to paginating through features by following the "next" links in the API response. It includes basic rate limit handling for status code 429.

Value

An sf object containing the retrieved spatial features.

Note

This function is not exported and should only be called by other functions within the package.

geofi documentation built on June 8, 2025, 9:32 p.m.