Import UI: add warning about tiddlers that already exist (#4956)

* Added message when tiddler being imported already exists

* Refactored some filters into a shared subfilter, optimized macro definitions

core/language/en-GB/Import.multids

@@ -15,8 +15,9 @@ Listing/Preview/Diff: Diff
 Listing/Preview/DiffFields: Diff (Fields)
 Listing/Rename/Tooltip: Rename tiddler before importing
 Listing/Rename/Prompt: Rename to:
-Listing/Rename/ConfirmRename : Rename tiddler
-Listing/Rename/CancelRename : Cancel
+Listing/Rename/ConfirmRename: Rename tiddler
+Listing/Rename/CancelRename: Cancel
+Listing/Rename/OverwriteWarning: A tiddler with this title already exists.
 Upgrader/Plugins/Suppressed/Incompatible: Blocked incompatible or obsolete plugin
 Upgrader/Plugins/Suppressed/Version: Blocked plugin (due to incoming <<incoming>> being older than existing <<existing>>)
 Upgrader/Plugins/Upgraded: Upgraded plugin from <<incoming>> to <<upgraded>>

core/ui/ImportListing.tid

@@ -2,27 +2,23 @@ title: $:/core/ui/ImportListing
 
 \define lingo-base() $:/language/Import/
 
-\define messageField()
-message-$(payloadTiddler)$
+\define messageField() message-$(payloadTiddler)$
+
+\define payloadTitleFilter() [<currentTiddler>get<renameField>minlength[1]else<payloadTiddler>]
+
+\define overWriteWarning()
+<$text text={{{[subfilter<payloadTitleFilter>!is[tiddler]then[]] ~[<lingo-base>addsuffix[Listing/Rename/OverwriteWarning]get[text]]}}}/>
 \end
 
-\define selectionField()
-selection-$(payloadTiddler)$
-\end
+\define selectionField() selection-$(payloadTiddler)$
 
-\define renameField()
-rename-$(payloadTiddler)$
-\end
+\define renameField() rename-$(payloadTiddler)$
 
 \define newImportTitleTiddler() $:/temp/NewImportTitle-$(payloadTiddler)$
 
-\define previewPopupState()
-$(currentTiddler)$!!popup-$(payloadTiddler)$
-\end
+\define previewPopupState() $(currentTiddler)$!!popup-$(payloadTiddler)$
 
-\define renameFieldState()
-$(currentTiddler)$!!state-rename-$(payloadTiddler)$
-\end
+\define renameFieldState() $(currentTiddler)$!!state-rename-$(payloadTiddler)$
 
 \define select-all-actions()
 <$list filter="[all[current]plugintiddlers[]sort[title]]" variable="payloadTiddler">
@@ -54,13 +50,13 @@ $(currentTiddler)$!!state-rename-$(payloadTiddler)$
 <$reveal type="nomatch" state=<<renameFieldState>> text="yes" tag="div">
 <$reveal type="nomatch" state=<<previewPopupState>> text="yes" tag="div" class="tc-flex">
 <$button class="tc-btn-invisible tc-btn-dropdown tc-flex-grow-1" set=<<previewPopupState>> setTo="yes">
-<span class="tc-small-gap-right">{{$:/core/images/right-arrow}}</span><$text text={{{[<currentTiddler>get<renameField>minlength[1]else<payloadTiddler>]}}}/>
+<span class="tc-small-gap-right">{{$:/core/images/right-arrow}}</span><$text text={{{[subfilter<payloadTitleFilter>]}}}/>
 </$button>
 <$button class="tc-btn-invisible tc-small-gap-left" set=<<renameFieldState>> setTo="yes" tooltip={{{[<lingo-base>addsuffix[Listing/Rename/Tooltip]get[text]]}}}>{{$:/core/images/edit-button}}</$button>
 </$reveal>
 <$reveal type="match" state=<<previewPopupState>> text="yes" tag="div">
 <$button class="tc-btn-invisible tc-btn-dropdown" set=<<previewPopupState>> setTo="no">
-<span class="tc-small-gap-right">{{$:/core/images/down-arrow}}</span><$text text={{{[<currentTiddler>get<renameField>minlength[1]else<payloadTiddler>]}}}/>
+<span class="tc-small-gap-right">{{$:/core/images/down-arrow}}</span><$text text={{{[subfilter<payloadTitleFilter>]}}}/>
 </$button>
 </$reveal>
 </$reveal>
@@ -70,12 +66,13 @@ $(currentTiddler)$!!state-rename-$(payloadTiddler)$
 </td>
 <td>
 <$view field=<<messageField>>/>
+<<overWriteWarning>>
 </td>
 </tr>
 <$reveal type="match" state=<<renameFieldState>> text="yes" tag="tr">
 <td colspan="3">
 <div class="tc-flex">
-<$edit-text tiddler=<<newImportTitleTiddler>>  default={{{[<currentTiddler>get<renameField>minlength[1]else<payloadTiddler>]}}} tag="input" class="tc-import-rename tc-flex-grow-1"/><span class="tc-small-gap-left"><$button  class="tc-btn-invisible" set=<<renameFieldState>> setTo="no" tooltip={{{[<lingo-base>addsuffix[Listing/Rename/CancelRename]get[text]]}}}>{{$:/core/images/close-button}}<$action-deletetiddler $tiddler=<<newImportTitleTiddler>>/></$button><span class="tc-small-gap-right"/></span><$button  class="tc-btn-invisible" set=<<renameFieldState>> setTo="no" tooltip={{{[<lingo-base>addsuffix[Listing/Rename/ConfirmRename]get[text]]}}}>{{$:/core/images/done-button}}<$action-setfield $field=<<renameField>> $value={{{[<newImportTitleTiddler>get[text]minlength[1]else<payloadTiddler>]}}} /><$action-deletetiddler $tiddler=<<newImportTitleTiddler>>/></$button>
+<$edit-text tiddler=<<newImportTitleTiddler>>  default={{{[subfilter<payloadTitleFilter>]}}} tag="input" class="tc-import-rename tc-flex-grow-1"/><span class="tc-small-gap-left"><$button  class="tc-btn-invisible" set=<<renameFieldState>> setTo="no" tooltip={{{[<lingo-base>addsuffix[Listing/Rename/CancelRename]get[text]]}}}>{{$:/core/images/close-button}}<$action-deletetiddler $tiddler=<<newImportTitleTiddler>>/></$button><span class="tc-small-gap-right"/></span><$button  class="tc-btn-invisible" set=<<renameFieldState>> setTo="no" tooltip={{{[<lingo-base>addsuffix[Listing/Rename/ConfirmRename]get[text]]}}}>{{$:/core/images/done-button}}<$action-setfield $field=<<renameField>> $value={{{[<newImportTitleTiddler>get[text]minlength[1]else<payloadTiddler>]}}} /><$action-deletetiddler $tiddler=<<newImportTitleTiddler>>/></$button>
 </div>
 </td>
 </$reveal>
@@ -91,4 +88,3 @@ $(currentTiddler)$!!state-rename-$(payloadTiddler)$
 </$list>
 </tbody>
 </table>
-