Several changes:

 - Wt 4 specific:
   - objectName() no longer present in id():
     The data-object-name attribute is used instead
   - Changed interface of WAbstractItemDelegate to reflect ownership
     The old interface got a non-owning pointer as argument, and returned a
     maybe-owning pointer.
     Now it gets non-owning pointer (which can be made owning with
     removeFromParent()), and returns an owning pointer (which may be
     nullptr).
   - Added script to add .h to includes
   - Documentation:
     - Documented Wt::Dbo::Session::addNew and Wt::Dbo::make_ptr
     - Documented LayoutImplementation, renamed Classic to JavaScript
     - Removed some extra "CharEncoding::" substitutions
   - timeTo: use std::chrono::seconds
   - Removed unused fontRegistryMutex_
   - Wt::utf8 and Wt::WString::fromUTF8 have become unnecessary
     Updating the examples to clarify that it's not necessary, the default
     encoding is UTF-8 now (unless changed with WString::setDefaultEncoding)

Author: RockinRoel

doc/tutorial/wt.doc

@@ -464,7 +464,9 @@ adjustments. It is for this purpose that layout managers have been
 added to Wt. These layout managers use JavaScript to compute the width
 and/or height of widgets based on dimensions of other widgets.
 
-TODO(Roel): what about flexbox?
+Since Wt 4, some layouts use CSS and flexbox by default, which works
+in many cases, but in some situations, you may want to opt for the
+JavaScript implementation instead.
 ****
 
 The +LetterWidget+ exposes a signal that indicates that the user chose

examples/blog/asciidoc/asciidoc.C

@@ -83,9 +83,9 @@ Wt::WString asciidoc(const Wt::WString& src)
   Wt::WString result;
 
   if (ok) {
-    result = Wt::utf8(readFileToString(htmlFileName));
+    result = Wt::WString(readFileToString(htmlFileName));
   } else
-    result = Wt::utf8("<i>Could not execute asciidoc</i>");
+    result = Wt::WString("<i>Could not execute asciidoc</i>");
 
   unlink(srcFileName.c_str());
   unlink(htmlFileName.c_str());

examples/blog/model/BlogUserDatabase.C

@@ -127,7 +127,7 @@ Wt::WString BlogUserDatabase::identity(const Wt::Auth::User& user,
   if (provider == Wt::Auth::Identity::LoginName)
     return user_->name;
   else if (provider == user_->oAuthProvider)
-    return Wt::utf8(user_->oAuthId);
+    return Wt::WString(user_->oAuthId);
   else
     return Wt::WString::Empty;
 }

examples/blog/model/Comment.C

@@ -81,7 +81,7 @@ void Comment::setText(const Wt::WString& src)
   // <div class="vspace"></div>
   replace(html, "<br /><br />", "<div class=\"vspace\"></div>");
 
-  textHtml_ = Wt::utf8(html);
+  textHtml_ = Wt::WString(html);
 }
 
 void Comment::setDeleted()

examples/chart3D/CsvUtil.C

@@ -35,7 +35,7 @@ void readFromCsv(std::istream& f, Wt::WAbstractItemModel *model,
 			       col + 1 - model->columnCount());
 
 	if (firstLineIsHeaders && csvRow == 0)
-          model->setHeaderData(col, Wt::cpp17::any(Wt::utf8(*i)));
+          model->setHeaderData(col, Wt::cpp17::any(Wt::WString(*i)));
 	else {
 	  int dataRow = firstLineIsHeaders ? csvRow - 1 : csvRow;
 
@@ -58,7 +58,7 @@ void readFromCsv(std::istream& f, Wt::WAbstractItemModel *model,
 	    if (*endptr == 0)
               data = Wt::cpp17::any(d);
 	    else
-              data = Wt::cpp17::any(Wt::utf8(s));
+              data = Wt::cpp17::any(Wt::WString(s));
 	  }
 
 	  model->setData(dataRow, col, data);

examples/charts/CsvUtil.C

@@ -35,7 +35,7 @@ void readFromCsv(std::istream& f, Wt::WAbstractItemModel *model,
 			       col + 1 - model->columnCount());
 
 	if (firstLineIsHeaders && csvRow == 0)
-          model->setHeaderData(col, Wt::cpp17::any(Wt::utf8(*i)));
+          model->setHeaderData(col, Wt::cpp17::any(Wt::WString(*i)));
 	else {
 	  int dataRow = firstLineIsHeaders ? csvRow - 1 : csvRow;
 
@@ -58,7 +58,7 @@ void readFromCsv(std::istream& f, Wt::WAbstractItemModel *model,
 	    if (*endptr == 0)
               data = Wt::cpp17::any(d);
 	    else
-              data = Wt::cpp17::any(Wt::utf8(s));
+              data = Wt::cpp17::any(Wt::WString(s));
 	  }
 
 	  model->setData(dataRow, col, data);

examples/composer/AttachmentEdit.C

@@ -54,10 +54,10 @@ AttachmentEdit::UploadInfo::UploadInfo(const Http::UploadedFile& f)
       + U"kb";
 
   std::u32string fn = static_cast<std::u32string>
-    (escapeText(WString::fromUTF8(info_.clientFileName())));
+    (escapeText(WString(info_.clientFileName())));
 
   downloadLink_
-    = this->addWidget(cpp14::make_unique<WAnchor>("", fn + U" (<i>" + WString::fromUTF8(info_.contentType())
+    = this->addWidget(cpp14::make_unique<WAnchor>("", fn + U" (<i>" + WString(info_.contentType())
                   + U"</i>) " + size));
 
   auto res = std::make_shared<WFileResource>(info_.contentType(),info_.spoolFileName());
@@ -195,8 +195,8 @@ std::vector<Attachment> AttachmentEdit::attachments()
       Http::UploadedFile& f = uploadInfo_[i]->info_;
       f.stealSpoolFile();
       result.push_back(Attachment
-		       (WString::fromUTF8(f.clientFileName()),
-			WString::fromUTF8(f.contentType()),
+		       (WString(f.clientFileName()),
+			WString(f.contentType()),
 			f.spoolFileName()));
     }
   }

examples/feature/oidc/OAuthAuthorizationEndpoint.C

@@ -34,5 +34,5 @@ OAuthAuthorizationEndpoint::OAuthAuthorizationEndpoint(const Wt::WEnvironment& e
   if (process_->validRequest()) {
     root()->addWidget(std::move(authwidget));
   } else
-    root()->addWidget(Wt::cpp14::make_unique<Wt::WText>(Wt::utf8("The request was invalid.")));
+    root()->addWidget(Wt::cpp14::make_unique<Wt::WText>(Wt::WString("The request was invalid.")));
 }

examples/feature/oidc/Oidc.C

@@ -65,7 +65,7 @@ private:
   {
     root()->clear();
     root()->addWidget(Wt::cpp14::make_unique<Wt::WText>(
-          Wt::utf8("Welcome, {1}").arg(id.name()), Wt::TextFormat::Plain));
+          Wt::WString("Welcome, {1}").arg(id.name()), Wt::TextFormat::Plain));
   }
 };
 

examples/feature/socketnotifier/SocketNotifier.C

@@ -261,7 +261,7 @@ private:
     startButton_->setText("Again");
     startButton_->enable();
     rssText_->setText("<pre>" +
-        escapeText(WString::fromUTF8(inStream_.str())) + "</pre>");
+        escapeText(inStream_.str()) + "</pre>");
     addText("Finished!<br/>Run again?<br/>");
     inStream_.str("");
     wApp->enableUpdates(false);