snapshots: add navigation links (#50010)

tests/test_snapshots.py

@@ -339,6 +339,25 @@ def test_form_snapshot_browse(pub, formdef_with_history):
     resp = resp.click(href='%s/view/' % snapshot.id)
     assert 'This form is readonly' in resp.text
     assert '<p>%s</p>' % localstrftime(snapshot.timestamp) in resp.text
+
+    assert '<a class="button disabled" href="#">&Lt;</a>' in resp.text
+    assert '<a class="button disabled" href="#">&LT;</a>' in resp.text
+    assert '<a class="button" href="../../%s/view/">&GT;</a>' % (snapshot.id - 1) in resp.text
+    assert '<a class="button" href="../../%s/view/">&Gt;</a>' % (snapshot.id - 6) in resp.text
+
+    resp = resp.click(href='../../%s/view/' % (snapshot.id - 1))
+    assert '<a class="button" href="../../%s/view/">&Lt;</a>' % snapshot.id in resp.text
+    assert '<a class="button" href="../../%s/view/">&LT;</a>' % snapshot.id in resp.text
+    assert '<a class="button" href="../../%s/view/">&GT;</a>' % (snapshot.id - 2) in resp.text
+    assert '<a class="button" href="../../%s/view/">&Gt;</a>' % (snapshot.id - 6) in resp.text
+
+    resp = resp.click(href='../../%s/view/' % (snapshot.id - 6))
+    assert '<a class="button" href="../../%s/view/">&Lt;</a>' % snapshot.id in resp.text
+    assert '<a class="button" href="../../%s/view/">&LT;</a>' % (snapshot.id - 5) in resp.text
+    assert '<a class="button disabled" href="#">&GT;</a>' in resp.text
+    assert '<a class="button disabled" href="#">&Gt;</a>' in resp.text
+
+    resp = resp.click(href='../../%s/view/' % snapshot.id)
     resp = resp.click('Description')
     assert resp.form['description'].value == 'this is a description (5)'
     assert [x[0].name for x in resp.form.fields.values() if x[0].tag == 'button'] == ['cancel']

wcs/admin/utils.py

@@ -62,4 +62,21 @@ def snapshot_info_block(snapshot):
         parts.append(misc.localstrftime(snapshot.timestamp))
     r += htmltext('<br />').join(parts)
     r += htmltext('</p>')
+    if snapshot.previous or snapshot.next:
+        r += htmltext('<p class="snapshots-navigation">')
+        if snapshot.id != snapshot.first:
+            r += htmltext(' <a class="button" href="../../%s/view/">&Lt;</a>' % (snapshot.first))
+            r += htmltext(' <a class="button" href="../../%s/view/">&LT;</a>' % (snapshot.previous))
+        else:
+            # currently browsing the first snapshot, display links as disabled
+            r += htmltext(' <a class="button disabled" href="#">&Lt;</a>')
+            r += htmltext(' <a class="button disabled" href="#">&LT;</a>')
+        if snapshot.id != snapshot.last:
+            r += htmltext(' <a class="button" href="../../%s/view/">&GT;</a>' % (snapshot.next))
+            r += htmltext(' <a class="button" href="../../%s/view/">&Gt;</a>' % (snapshot.last))
+        else:
+            # currently browsing the last snapshot, display links as disabled
+            r += htmltext(' <a class="button disabled" href="#">&GT;</a>')
+            r += htmltext(' <a class="button disabled" href="#">&Gt;</a>')
+        r += htmltext('</p>')
     return r.getvalue()

wcs/qommon/static/css/dc2/admin.scss

@@ -1920,6 +1920,10 @@ ul.snapshots-list .new-day, ul.snapshots-list .has-label {
 	display: block;
 }
 
+p.snapshots-navigation {
+       text-align: center;
+}
+
 #sidebar-custom-views .as-data-source {
 	font-weight: normal;
 }

wcs/snapshots.py

@@ -102,6 +102,54 @@ class Snapshot:
                 self._user = UnknownUser()
         return self._user
 
+    def load_history(self):
+        if not self.instance:
+            self._history = []
+            return
+        history = get_publisher().snapshot_class.select_object_history(self.instance)
+        self._history = [s.id for s in history]
+
+    @property
+    def previous(self):
+        if not hasattr(self, '_history'):
+            self.load_history()
+
+        try:
+            idx = self._history.index(self.id)
+        except ValueError:
+            return None
+        if idx == 0:
+            return None
+        return self._history[idx - 1]
+
+    @property
+    def next(self):
+        if not hasattr(self, '_history'):
+            self.load_history()
+
+        try:
+            idx = self._history.index(self.id)
+        except ValueError:
+            return None
+        try:
+            return self._history[idx + 1]
+        except IndexError:
+            return None
+
+    @property
+    def first(self):
+        if not hasattr(self, '_history'):
+            self.load_history()
+
+        return self._history[0]
+
+    @property
+    def last(self):
+        if not hasattr(self, '_history'):
+            self.load_history()
+
+        return self._history[-1]
+
     def restore(self, as_new=True):
         instance = self.instance
         if as_new: