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Remove total count comparison for next and previous page check #158

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5 changes: 5 additions & 0 deletions CHANGELOG.md
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,11 @@ These are the latest changes on the project's `master` branch that have not yet
Follow the same format as previous releases by categorizing your feature into "Added", "Changed", "Deprecated", "Removed", "Fixed", or "Security".
--->

## [0.5.0] - 2025-05-02

### Changed
- Removed a redundant check for the total amount of items in order to determine if there is a next or previous page. This gets rid of two `select count(*)` queries that were being executed, speeding up the pagination process.

## [0.4.0] - 2023-10-06

### Changed
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17 changes: 8 additions & 9 deletions lib/rails_cursor_pagination/paginator.rb
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Expand Up @@ -216,11 +216,10 @@ def custom_order_field?
# @return [TrueClass, FalseClass]
def previous_page?
if paginate_forward?
# When paginating forward, we can only have a previous page if we were
# provided with a cursor and there were records discarded after applying
# this filter. These records would have to be on previous pages.
@cursor.present? &&
filtered_and_sorted_relation.reorder('').size < total
# When paginating forward, if a cursor is present it must mean we have
# come from a previous page that has provided us a cursor. Therefore, we
# can assume that there is a previous page.
@cursor.present?
else
# When paginating backwards, if we managed to load one more record than
# requested, this record will be available on the previous page.
Expand All @@ -237,10 +236,10 @@ def next_page?
# requested, this record will be available on the next page.
records_plus_one.size > @page_size
else
# When paginating backward, if applying our cursor reduced the number
# records returned, we know that the missing records will be on
# subsequent pages.
filtered_and_sorted_relation.reorder('').size < total
# When paginating backward, if a cursor is present it must mean we have
# come from a next page that has provided us a cursor. Therefore, we
# can assume that there is a next page.
@cursor.present?
end
end

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