Germany Meetups: November 29th Frankfurt, November 30th Munich

After our initial kick-off meetup in Utrecht, The Netherlands on November 27th, John and I will be in Frankfurt at the 29th of November.

Frankfurt Meetup

We will be hosting our second meetup in the Ambassador Club on the 7th floor of Fleming’s Selection Hotel at the Eschenheimer Tor 2 in Frankfurt-City.

You will be informed on the latest features of our v17.2 release, and you’ll be able to discuss them with me or other DevExpress customers. The drinks and snacks are on us and we’re looking forward meeting you.

If you want to join this meetup, make sure to register you seat by clicking here.


Munich Meetup

On November 30, John and I will be in Munich for our 3rd Meetup. We’ll host this one in the Augustiner Keller und Biergarten, and while we go over the awesome new features of v17.2, you’ll be paying attention while having a beer and some snacks.

I’d love to talk with all of you and hear your comments and feedback, and maybe even some suggestions for our next major release.

If you want to join this meetup, make sure to register you seat by clicking here.

If you can't make it to any of these locations, let me know so we can investigate possible other locations for additional meetups.

I hope to see you in Frankfurt or Munich!

DevExtreme: New TypeScript declarations and improved Angular typings (v17.2)

One of the things we support from the very first release of DevExtreme is TypeScript.


As many of you know, TypeScript and its tooling allow us to use compile-time type checks and it offers support for classes and interfaces. Because of these features, one is able to build large scale JavaScript applications. In fact Google is using TypeScript for developing Angular.

With our v17.2 release we have improved our TypeScript declarations for the DevExtreme widgets API as well as the Angular integration layer.

What does this mean?

In the previous releases, most of the classes in the DevExtreme API had weakly typed properties (of type ‘any’). This means that compile time type checking always resulted in a successful build even if you try to bind a string value to a property which needs a number.

With v17.2 we have made the DevExtreme API strongly typed which results in improved code editor hints:


One of the cool features of TypeScript is the use of union types (‘|’ sign). This allows us to specify a number of types to be used like shown in the following table:

  v17.1 v17.2
dxDateBoxOptions value? : any value? : Date | number | string
All widgets dataSource? : any dataSource? : Array | DataSource | DataSourceOptions | string;

To make the DevExtreme API more fluent, we’ve also introduced the use of ‘type’ declarations like:

     export type format = string | ((value: number | Date) => string) | {        
        type?: string,
        precision?: number,
        currency?: string,
        formatter?: ((value: number | Date) => string),
        parser?: ((value: string) => number | Date)
     // in dxDateBoxOptions
     displayFormat?: format;


While we were working on these developer improvements, we worked on the IntelliSense support as well. All the information you normally look up on our documentation site will now show up in the Quick Info tooltip and it is used in the code-completion to increase your productivity.


What about Angular?

Because Angular is written in TypeScript, all these developer sweetness works for Angular as well!

We have strongly typed the Angular Component properties which results in less runtime errors because the build process of an Angular application will do the type-checking for us.


And while coding, we are now able to give you short descriptions through the Quick Info panel in IntelliSense as well.


Try it now?

So ready for a test-drive?

These new features are included in the v17.2 pre-beta that is available through npm right now. Please note that this pre-beta may contain some bugs and is not intended to be used in production: 

npm install devextreme@17.2.1-pre-beta

Learn more about DevExtreme's pre-releases in this blog post.

Like it?

Let me know by replying to this post if you like the features outlined in this post.

DevExtreme with and without jQuery (v17.2)

When we started developing DevExtreme back in 2012, jQuery was the de-facto library everybody used. It gave us the possibility to create a set of feature-rich widgets such as the DataGrid, TreeList, Scheduler and more in a short time-frame.


If we take a look at today’s front-end development landscape, there are a number of really popular JavaScript frameworks like Angular and React and new ones appear every day.

When using one of those frameworks, jQuery seems to become less important which is understandable since jQuery serves a different purpose.

jQuery’s primary purpose is DOM-manipulation while those frameworks allow you to follow several design patterns (MVVM/MVC) and support things like client-side model-binding and unit testing.

Some of those frameworks have some really cool features e.g. Angular’s server-side rendering.
(Yes, we’re working on that)
If we want to support server-side rendering, jQuery is preventing us from doing so.

At the same time we know that jQuery is still a very popular library which is used in a huge number of projects, but we also want you to be able to use everything that your framework of choice has to offer.

For these reasons we decided to remove the jQuery dependency in DevExtreme v17.2, and have a jQuery integration module like we have for Angular.

What does this mean?

If you want to use jQuery with DevExtreme, please do so. The DevExtreme widgets will just work. If you don’t want to use jQuery, then don’t! The widgets will still work.

If you’re using something like Angular and don’t need to include jQuery, it will reduce the download time of your application. Another nice ‘side-effect’ is that there is a performance improvement of our widgets up to 30% in some scenarios!

The chart below shows the performance improvements on the jQuery-free widgets vs. the jQuery-included widgets.  


Server-Side rendering

As I mentioned before, one of the really cool things for Angular we’re working on is Server-Side rendering (SSR). Without SSR, your web-page will only contain a DOM element like a <DIV> which will be dynamically filled with the UI of your app during page load. As a result, your initial page-load takes a bit longer and because of your ‘empty’ page, indexation by search engines is very difficult because of the client-side rendering. (Search engine spiders only execute some basic  JavaScript)

With Server-Side rendering, the page with the initial view of your app is fully rendered at the server. Angular makes this possible by executing the same JavaScript on a NodeJS server process.

For your end-user, it means that they don’t need to look at an ‘empty’ page, but they have the initial view immediately in their browser.

Making jQuery optional is a first step towards SSR.

Search Engine Optimization

SSR will also have a very positive effect on search engine spiders since no client-side JavaScript needs to be executed before your initial view is shown. The spider is able to crawl all the links in the initial view, and will nicely follow and index all of them.

Your entire Angular app will be index properly!

Other benefits

As a result of removing the jQuery dependency, DevExtreme can now work with jQuery.Deferred as well as ES6 Native Promises for asynchronous operations.

For all of you using DevExtreme in other frameworks like Aurelia, React, VueJS and others, you don’t need to include jQuery anymore and you can skip the jQuery API for creating, updating, event-binding and destroying DevExtreme Widgets.

Try it now?

So have we whet your appetite and you want to give it a test-drive?

These new features are included in the v17.2 pre-release that is available via npm right now. Please note that this pre-release may contain some bugs and is not intended to be used in production: 

npm install devextreme@17.2.2-pre-beta

Learn more about DevExtreme's pre-releases in this blog post.

Like it?

Let me know by replying to this post if you like this improvement.

DevExtreme: A new set of themes and palettes (v17.2)

Since the first DevExtreme release, we shipped the product with a generic theme in both light and dark color schemes. We wanted to avoid color accents so the widgets would fit in any design.

For us this meant that we needed to customize quite a bit in our demos like the DevAV and GolfClub projects to give them their own unique visual appearance.

As a result, we occasionally got questions from you about customizing the generic theme, or use one of those demo themes.

Because we value your feedback, with v17.2 we will give you 5 totally new themes that you can use in your DevExtreme projects:

Soft Blue, Carmine, Green Mist, Dark Moon and Dark Violet.


Customizing your entire application

Each new theme makes every single widget, from Button to Data Grid look vivid and shiny. The only thing you need to do is include the desired theme’s css file in your page and optionally add your own customizations to it.

All the new themes will be available as separate css files e.g. dx.generic.carmine.css. They are included in the installation package and on the DevExtreme CDN which hosts the new release.

Not enough?

Ok, so for our visualization widgets, we’ve taken things a bit further; besides the themes, we have added a new palette with every theme for these widgets to make them stand out. 


A palette is basically a set of colors for each series, range or area in widgets like the Chart, Pie Chart, Polar Chart, Circular Gauge, Linear Gauge, Vector Map, Tree Map and Funnel.

You can apply an individual palette to one control or to all the controls without including different css files.

If you want to use a palette for a single widget, you can use the palette property like:

var chartOptions = {
    palette: 'Dark Moon', // or 'Carmine', 'Dark Violet', 'Soft Blue', 'Green Fog'


If you want to change the palette for all widgets, you can call the changePalette method at the start of your application:

DevExpress.viz.currentPalette('Dark Moon'); // or 'Carmine', 'Dark Violet', 'Soft Blue', 'Green Fog'


Play around with the demos

Once we have officially released our v17.2 version, the DevExtreme web-site will be updated as well so you can have a look how those new themes look by selecting one in the dropdown of the DevExtreme Gallery.


The ThemeBuilder

One of the things I love about the new themes is that we have created them with our own DevExtreme ThemeBuilder. And now that we have those themes, the ThemeBuilder itself will be updated with the official v17.2 release to include these themes as well.

This means that you can use one of the themes as a starting point to create your own!

Can’t wait for the official release?

You can start with the Soft Blue, Carmine, Green Mist, Dark Moon and Dark Violet themes today by getting the pre-beta version of DevExtreme through npm or bower by using the following command in your project folder:

npm install devextreme@17.2.2-pre-beta

Let me know what you think of these new themes!

Chart enhancements on WinForms (v17.2)

In v17.2 of our WinForms Charts, we’ve added some useful features that both of you, the developer, and your end-users might appreciate.

Criteria Based Filtering

The Chart control already supported filtering on series, but in this release we have replaced the DataFilter property with the FilterCriteria and FilterString properties. This makes filtering more powerful and is also inline with several other controls like the Grid, Reporting and XPO. It allows you to use the DevExpress Criteria Language to filter series.

It also allows you to use the FilterControl or the Filtering UI Context to select the data which is used by the Chart control without writing any code.


Because of this change, you can use one filter control which manages the data for a Grid as well as a Chart!


Bind a Chart to Grid data

In the previous releases you always needed to bind the data to a DataSource like a collection of objects or a DataReader. In scenarios which involve a grid and a chart, these DataSources where used by both controls. With custom unbound grid columns, grouping and filtering  you always needed to code some additional mechanism to get that data in the chart as well.

With v17.2, we have added a ControlRowSource component which allows you to bind the chart directly to the Grid control. With this feature, the chart doesn’t use the same DataSource as the grid, but it will actually use the rows and columns available in the grid as its DataSource. It will make use of things like Grouping, Sorting, Filtering which might have been set in the Grid when supplying data to the Chart.

This also works in combination with the Treelist, Listbox and VerticalGrid controls.

Grid Data In Chart

Use a Chart as Grid Cell Editor

With v17.2 we implemented a long requested feature; Use a chart as Grid Cell Editor!

This gives you the possibility to design beautiful master-detail data visualizations as you can see:

Cell Chart

This functionality is based on the RepositoryItemAnyControl class and is now possible because we have implemented the IAnyControlEdit interface on the Chart control.


With this release we’ve taken a big step in letting different controls make use of each others functionality. For you this means writing less code and better performance. This will result in an even better experience for your end-users.

Talking about performance and user experience; have you seen Julian’s blog post about that we’ve done with the XtraGrid in v17.2?

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