# page, and use the last item on this page as a filter for
# retrieving the next page. Ideally the API would do this for
# us, but it doesn't (yet).
- nextpage_operator = /\bdesc$/i =~ @order[0] ? '<' : '>'
+
+ # To avoid losing items that have the same created_at as the
+ # last item on this page, we retrieve an overlapping page with a
+ # "created_at <= last_created_at" filter, then remove duplicates
+ # with a "uuid not in [...]" filter (see below).
+ nextpage_operator = /\bdesc$/i =~ @order[0] ? '<=' : '>='
+
@objects = []
@name_link_for = {}
kind_filters.each do |attr,op,val|
end
end
@objects = @objects.to_a.sort_by(&:created_at)
- @objects.reverse! if nextpage_operator == '<'
+ @objects.reverse! if nextpage_operator == '<='
@objects = @objects[0..@limit-1]
@next_page_filters = @filters.reject do |attr,op,val|
- attr == 'created_at' and op == nextpage_operator
- end
-
- # We are using created_at time slightly greater/lower than the last object created_at (see next block comment).
- # This would mean that the server would now return the previous last item(s) with matching created_at again.
- # Hence, we need to remove the previous last_uuids from results before displaying the rest of the results
- # to prevent "infinite" infinite scrolling.
- if params['last_uuids'] and @objects.any?
- last_uuids = JSON.parse params['last_uuids']
- @objects.reject! do |obj|
- last_uuids.include? obj.uuid
- end
+ (attr == 'created_at' and op == nextpage_operator) or
+ (attr == 'uuid' and op == 'not in')
end
if @objects.any?
last_created_at = @objects.last.created_at
- last_uuids = [] if (last_created_at != params[:last_created_at])
+ last_uuids = []
@objects.each do |obj|
last_uuids << obj.uuid if obj.created_at.eql?(last_created_at)
end
- # In order to prevent losing item(s) that have the same created_at time as the current page last item,
- # next page should look for objects with created_at time slightly greater/lower than the current last,
- # and remove them if they are part of previous page's last_uuids (see the previous block)
- if nextpage_operator == '<'
- last_created_at += 1
- else
- last_created_at -= 1
- end
-
@next_page_filters += [['created_at',
nextpage_operator,
last_created_at]]
+ @next_page_filters += [['uuid', 'not in', last_uuids]]
@next_page_href = url_for(partial: :contents_rows,
- last_uuids: last_uuids.to_json,
- last_created_at: @objects.last.created_at,
limit: @limit,
filters: @next_page_filters.to_json)
else
include_linked: true,
filters: @filters,
offset: @offset)
- @next_page_href = next_page_href(partial: :contents_rows, filters: @filters.to_json)
+ @next_page_href = next_page_href(partial: :contents_rows,
+ filters: @filters.to_json,
+ order: @order.to_json)
end
preload_links_for_objects(@objects.to_a)
projects / arvados.git / blobdiff