<p></p>
<p><b>@tomhughes</b> commented on this pull request.</p>

<hr>

<p>In <a href="https://github.com/openstreetmap/openstreetmap-website/pull/4239#discussion_r1320131860">app/controllers/diary_entries_controller.rb</a>:</p>
<pre style='color:#555'>> +  def get_page_items(items, includes)
+    id_column = "#{items.table_name}.id"
+    page_items = if params[:before]
+                   items.where("#{id_column} < ?", params[:before]).order(:id => :desc)
+                 elsif params[:after]
+                   items.where("#{id_column} > ?", params[:after]).order(:id => :asc)
+                 else
+                   items.order(:id => :desc)
+                 end
+
+    page_items = page_items.limit(20)
+    page_items = page_items.includes(includes)
+    page_items = page_items.sort.reverse
+
+    newer_items_id = page_items.count.positive? && items.exists?(["#{id_column} > ?", page_items.first.id]) && page_items.first.id
+    older_items_id = page_items.count.positive? && items.exists?(["#{id_column} < ?", page_items.last.id]) && page_items.last.id
</pre>
<p dir="auto">I think it would be better to write these as guarded assignments - it took me quite a while to figure out what you were doing. I suggest doing:</p>
<div class="highlight highlight-source-ruby" dir="auto"><pre class="notranslate"><span class="pl-s1">newer_items_id</span> <span class="pl-c1">=</span> <span class="pl-en">page_items</span><span class="pl-kos">.</span><span class="pl-en">first</span><span class="pl-kos">.</span><span class="pl-en">id</span> <span class="pl-k">if</span> <span class="pl-en">page_items</span><span class="pl-kos">.</span><span class="pl-en">count</span><span class="pl-kos">.</span><span class="pl-en">positive?</span> && <span class="pl-en">items</span><span class="pl-kos">.</span><span class="pl-en">exists?</span><span class="pl-kos">(</span><span class="pl-kos">[</span><span class="pl-s">"<span class="pl-s1"><span class="pl-kos">#{</span><span class="pl-en">id_column</span><span class="pl-kos">}</span></span> > ?"</span><span class="pl-kos">,</span> <span class="pl-en">page_items</span><span class="pl-kos">.</span><span class="pl-en">first</span><span class="pl-kos">.</span><span class="pl-en">id</span><span class="pl-kos">]</span><span class="pl-kos">)</span></pre></div>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />Reply to this email directly, <a href="https://github.com/openstreetmap/openstreetmap-website/pull/4239#pullrequestreview-1617922205">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/AAK2OLNPXHAF73DHNYGT5ZTXZNGHHANCNFSM6AAAAAA4P7QODY">unsubscribe</a>.<br />You are receiving this because you are subscribed to this thread.<img src="https://github.com/notifications/beacon/AAK2OLOKAG44ZCQMGGJOG3DXZNGHHA5CNFSM6AAAAAA4P7QOD2WGG33NNVSW45C7OR4XAZNRKB2WY3CSMVYXKZLTORJGK5TJMV32UY3PNVWWK3TUL5UWJTTAN6EJ2.gif" height="1" width="1" alt="" /><span style="color: transparent; font-size: 0; display: none; visibility: hidden; overflow: hidden; opacity: 0; width: 0; height: 0; max-width: 0; max-height: 0; mso-hide: all">Message ID: <span><openstreetmap/openstreetmap-website/pull/4239/review/1617922205</span><span>@</span><span>github</span><span>.</span><span>com></span></span></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/openstreetmap/openstreetmap-website/pull/4239#pullrequestreview-1617922205",
"url": "https://github.com/openstreetmap/openstreetmap-website/pull/4239#pullrequestreview-1617922205",
"name": "View Pull Request"
},
"description": "View this Pull Request on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>