Resolve URLs through composed redirects and canonicals

Resolves URL vectors with the same composed 3xx redirect plus declared `rel=canonical` fold-map engine used by [pagerank()] and [build_fold_map()]. This helper performs signal folding only; it does not perform URL syntax canonicalization.

Usage

resolve_folded_urls(
  urls,
  redirects_df = NULL,
  canonicals_df = NULL,
  redirect_from_col = "from",
  redirect_to_col = "to",
  canonical_from_col = "from",
  canonical_to_col = "to",
  duplicate_from_policy = c("strict", "first_wins", "last_wins", "most_frequent",
    "prune_source", "resolve_if_consistent"),
  loop_handling = c("error", "prune_loop", "break_arrow"),
  canonical_duplicate_from_policy = c("strict", "first_wins", "last_wins",
    "most_frequent", "prune_source", "resolve_if_consistent"),
  canonical_loop_handling = c("error", "prune_loop", "break_arrow"),
  canonical_conflict_policy = c("redirect_wins", "error", "canonical_wins")
)

Arguments

urls

Character vector of URLs to resolve.

redirects_df

Optional data frame of redirect rules, or `NULL`.

canonicals_df

Optional data frame of declared canonical links, or `NULL`.

redirect_from_col, redirect_to_col

From/to columns in `redirects_df`. Default `"from"` / `"to"`.

canonical_from_col, canonical_to_col

From/to columns in `canonicals_df`. Default `"from"` / `"to"`.

duplicate_from_policy

How to handle a redirect source with multiple distinct targets. See [resolve_redirects()]. Default `"strict"`.

loop_handling

How to handle redirect cycles. See [resolve_redirects()]. Default `"error"`. Also governs cross-signal cycles in the composed graph.

canonical_duplicate_from_policy

How to handle a canonical source with multiple distinct declared canonicals. Reuses the `duplicate_from_policy` enum. Default `"strict"`.

canonical_loop_handling

How to handle cycles among declared canonicals. Reuses the `loop_handling` enum. Default `"error"`.

canonical_conflict_policy

How to resolve a redirect-vs-canonical disagreement on the **same source** URL. One of:

`"redirect_wins"`

(Default) The 3xx redirect wins; a canonical declared on a URL that itself redirects is ignored and flagged, never transferred onto the redirect target.

`"error"`

Error when a redirect and a canonical disagree on the same source (after audit context is computed). Sources where the two signals agree do not error.

`"canonical_wins"`

The declared canonical wins for that source; still flagged in the audit. The explicit exception to the default ignored-canonical-on-redirecting-source rule.

Value

A data frame with `original`, `resolved`, `changed`, and `signal` columns. The exported fold map is attached as attribute `"fold_map"` and cross-signal audit tables are attached as `"conflicts"` and `"ignored_canonicals"`.

Examples

redirects <- data.frame(from = "B", to = "C")
canonicals <- data.frame(from = "A", to = "B")
resolve_folded_urls(c("A", "B", "X"), redirects, canonicals)
#>   original resolved changed    signal
#> 1        A        C    TRUE canonical
#> 2        B        C    TRUE  redirect
#> 3        X        X   FALSE      <NA>