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Diffstat (limited to 'src/content/util/getChronologyRelations.js')
-rw-r--r-- | src/content/util/getChronologyRelations.js | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/content/util/getChronologyRelations.js b/src/content/util/getChronologyRelations.js new file mode 100644 index 00000000..11281e75 --- /dev/null +++ b/src/content/util/getChronologyRelations.js @@ -0,0 +1,42 @@ +export default function getChronologyRelations(thing, { + contributions, + linkArtist, + linkThing, + getThings, +}) { + // One call to getChronologyRelations is considered "lumping" together all + // contributions as carrying equivalent meaning (for example, "artist" + // contributions and "contributor" contributions are bunched together in + // one call to getChronologyRelations, while "cover artist" contributions + // are a separate call). getChronologyRelations prevents duplicates that + // carry the same meaning by only using the first instance of each artist + // in the contributions array passed to it. It's expected that the string + // identifying which kind of contribution ("track" or "cover art") is + // shared and applied to all contributions, as providing them together + // in one call to getChronologyRelations implies they carry the same + // meaning. + + const artistsSoFar = new Set(); + + contributions = contributions.filter(({who}) => { + if (artistsSoFar.has(who)) { + return false; + } else { + artistsSoFar.add(who); + return true; + } + }); + + return contributions.map(({who}) => { + const things = Array.from(new Set(getThings(who))); + const index = things.indexOf(thing); + const previous = things[index - 1]; + const next = things[index + 1]; + return { + index: index + 1, + artistLink: linkArtist(who), + previousLink: previous ? linkThing(previous) : null, + nextLink: next ? linkThing(next) : null, + }; + }); +} |