Preview 7 of DotVVM 5.0

Few weeks ago, we published Preview 7 of DotVVM 5.0 which contains a number of big features ready to be tested.

Some of them were present in the earlier preview, but there have been several months of work and plenty of bug fixes and further improvements, for example:

• Switch from Newtonsoft.Json to System.Text.Json – better support for collection population, fixed several issues when using custom JsonConverters, improved handling of Enums
• New DotVVM.Sitemap package – auto-generate sitemap.xml from route table
• Localizable routes – we made some changes to make the API more easy to use
• JsComponent support for Svelte – from now, you can host Svelte components in DotVVM pages similar to React ones

Performance improvements

We also made more performance tests to see how the transition from Newtonsoft.Json to System.Text.Json helped, and the results are pretty impressive:

In our first scenario, the InitialGet benchmark tries to serialize a complex viewmodel we borrowed from one real-world project (it has ~380 kB of JSON which is quite heavy) and serialize it.

The Postback benchmark receives the serialized viewmodel (the same 380kB one), populates the C# object with it, makes a trivial change to one value, and serializes the result back (that’s why it takes more time – it involves both deserialization and serialization).

As you can see, the InitialGet is 3x faster and allocates 3.5x less memory, and Postback is 6x faster while allocating 5.5x less memory.

The difference is not caused entirely by switching the libraries – we made a couple of further optimizations, and a lot of savings is likely thanks to working directly with UTF-8 stream without the need to expand it to string (which may take up to twice as much memory).

While you may expect breaking changes when upgrading to DotVVM 5 because of different behavior of the JSON libraries, we believe the benefits in terms of performance are interesting enough for the upgrade effort to be worthy.

Bootstrap, Business Pack, and DotVVM Contrib Packages

Along with DotVVM 5.0 Preview 7, we also released the Preview 7 version of all commercial packages (Bootstrap for DotVVM and Business Pack), and also the community-authored DotVVM Contrib components.

We encourage everyone to try DotVVM 5.0 Preview 7, and we’ll be happy for any feedback at DotVVM Forum.