Register a document extractor

Register a document extractor

Usage

gr_register_extractor(name, extensions, fn, description = "")

Arguments

name

Short name for the extractor.

extensions

Character vector of file extensions it claims.

fn

Function of (path, opts) returning a data frame with columns text, and optionally page, section, kind. Pages it could not turn into text can be listed in attr(result, "gr_unread_pages"); an answer drawn from the document is then marked partial, as it is for a PDF page that needed OCR and did not get it.

description

One-line description shown by gr_extractors().

Value

Invisibly, name.

See also

gr_extractors(), gr_ingest(), gr_register_cleaner()

Other ingest functions: gr_clean(), gr_cleaners(), gr_document, gr_extractors(), gr_ingest(), gr_ingest_spec(), gr_register_cleaner()

Examples

# A minimal extractor for tab-separated files: one block per row.
gr_register_extractor("tsv", "tsv", description = "TSV, one block per row",
  fn = function(path, opts) {
    d <- utils::read.delim(path, stringsAsFactors = FALSE)
    data.frame(text = apply(d, 1, paste, collapse = " | "), kind = "table")
  })
subset(gr_extractors(), name == "tsv")
#>     name extensions            description needs available
#> tsv  tsv        tsv TSV, one block per row            TRUE