`oa_request` makes a request and downloads bibliographic records from
OpenAlex database https://openalex.org/.
The function oa_request queries OpenAlex database using a query
formulated through the function oa_query.
Arguments
- query_url
Character string. A search query formulated using the OpenAlex API language and can be generated with
oa_query.- per_page
Numeric. Number of items to download per page. The per-page argument can assume any number between 1 and 200. Defaults to 200.
- paging
Character. Either "cursor" for cursor paging or "page" for basic paging. When used with `options$sample` and or `pages`, paging is also automatically set to basic paging: `paging = "page"` to avoid duplicates and get the right page. See https://docs.openalex.org/how-to-use-the-api/get-lists-of-entities/paging.
- pages
Integer vector. The range of pages to return. If NULL, return all pages.
- count_only
Logical. If TRUE, the function returns only the number of item matching the query. Defaults to FALSE.
- mailto
Character string. Gives OpenAlex an email to enter the polite pool.
- api_key
Character string. Your OpenAlex Premium API key, if available.
- verbose
Logical. If TRUE, print information about the querying process. Defaults to TRUE.
Value
a data.frame or a list of bibliographic records.
For more extensive information about OpenAlex API, please visit: <https://docs.openalex.org>
Examples
if (FALSE) {
### EXAMPLE 1: Full record about an entity.
# Query to obtain all information about a particular work/author/institution/etc.:
# The following paper is associated to the OpenAlex-id W2755950973.
# Aria, M., & Cuccurullo, C. (2017). bibliometrix:
# An R-tool for comprehensive science mapping analysis.
# Journal of informetrics, 11(4), 959-975.
res <- oa_request(query_url = "https://api.openalex.org/works/W2755950973")
# The author Massimo Aria is associated to the OpenAlex-id A5069892096.
query_author <- oa_query(
identifier = "A5069892096",
entity = "authors"
)
query_author
res <- oa_request(
query_url = query_author,
count_only = FALSE,
verbose = FALSE
)
### EXAMPLE 2: all works citing a particular work.
# Query to search all works citing the article:
# Aria, M., & Cuccurullo, C. (2017). bibliometrix:
# An R-tool for comprehensive science mapping analysis.
# Journal of informetrics, 11(4), 959-975.
# published in 2021.
# The paper is associated to the OpenAlex id W2755950973.
# Results have to be sorted by relevance score in a descending order.
query2 <- oa_query(
identifier = NULL,
entity = "works",
cites = "W2755950973",
from_publication_date = "2021-12-01",
to_publication_date = "2021-12-31",
search = NULL,
endpoint = "https://api.openalex.org"
)
res2 <- oa_request(
query_url = query2,
count_only = FALSE,
verbose = FALSE
)
### EXAMPLE 3: All works matching a string in their title
# Query to search all works containing the exact string
# "bibliometric analysis" OR "science mapping" in the title, published in 2020 or 2021.
# Results have to be sorted by relevance score in a descending order.
query3 <- oa_query(
entity = "works",
title.search = c("bibliometric analysis", "science mapping"),
from_publication_date = "2021-12-01",
to_publication_date = "2021-12-31"
)
res3 <- oa_request(
query_url = query3,
count_only = FALSE,
verbose = FALSE
)
### EXAMPLE 4: How to check how many works match a query
# Query to search all works containing the exact string
# "bibliometric analysis" OR "science mapping" in the title, published in 2020 or 2021.
# Query only to know how many works could be retrieved (count_only=TRUE)
query4 <- oa_query(
entity = "works",
title.search = c("bibliometric analysis", "science mapping"),
from_publication_date = "2020-01-01",
to_publication_date = "2021-12-31"
)
res4 <- oa_request(
query_url = query4,
count_only = TRUE,
verbose = FALSE
)
res4$count # number of items retrieved by our query
}