( numPages: number, activePage: number, )
| 27 | * into a UI-friendly list. |
| 28 | */ |
| 29 | export const buildPagedList = ( |
| 30 | numPages: number, |
| 31 | activePage: number, |
| 32 | ): ("left" | "right" | number)[] => { |
| 33 | if (numPages <= TOTAL_PAGE_BLOCKS) { |
| 34 | return range(1, numPages); |
| 35 | } |
| 36 | |
| 37 | const isInvalidActivePage = activePage > numPages || activePage < 1; |
| 38 | const pageBeforeLast = numPages - 1; |
| 39 | const startPage = isInvalidActivePage |
| 40 | ? 1 + PAGE_NEIGHBORS |
| 41 | : Math.max(activePage - PAGE_NEIGHBORS, 2); |
| 42 | const endPage = isInvalidActivePage |
| 43 | ? numPages - PAGE_NEIGHBORS |
| 44 | : Math.min(activePage + PAGE_NEIGHBORS, pageBeforeLast); |
| 45 | |
| 46 | let pages: ReturnType<typeof buildPagedList> = range(startPage, endPage); |
| 47 | |
| 48 | const singleSpillOffset = PAGES_TO_DISPLAY - pages.length - 1; |
| 49 | const hasLeftOverflow = startPage > 2; |
| 50 | const hasRightOverflow = endPage < pageBeforeLast; |
| 51 | |
| 52 | if (hasLeftOverflow && !hasRightOverflow) { |
| 53 | const extraPages = range(startPage - singleSpillOffset, startPage - 1); |
| 54 | pages = ["left", ...extraPages, ...pages]; |
| 55 | } else if (!hasLeftOverflow && hasRightOverflow) { |
| 56 | const extraPages = range(endPage + 1, endPage + singleSpillOffset); |
| 57 | pages = [...pages, ...extraPages, "right"]; |
| 58 | } else if (hasLeftOverflow && hasRightOverflow) { |
| 59 | pages = ["left", ...pages, "right"]; |
| 60 | } |
| 61 | |
| 62 | return [1, ...pages, numPages]; |
| 63 | }; |
| 64 | |
| 65 | /** |
| 66 | * Calculates the current offset from the start of a paginated dataset |
no test coverage detected