/en/vaadin-tree-grid-lazy-loading-filtering-sorting/

[mlopezFC]

https://www.flowingcode.com/en/vaadin-tree-grid-lazy-loading-filtering-sorting/

[mlopezFC]

Frank wrote on 2021-10-05 (comment migrated from the previous website):

Hi Paola, great example! The code is very well written and instructive. Thank you very much for sharing! Just one question: The TreeGrid is scrollable (which is great) but just uses about half of my screen (notebook with 1920 x 1080). The lower part is empty. Where could I adapt the height of the TreeGrid?

[mlopezFC]

Paola De Bartolo wrote on 2021-10-06 (comment migrated from the previous website):

Hi Frank, thanks for the feedback, it’s much appreciated! Regarding your question, you can set height of TreeGrid by using setHeight method (for e.g. treeGrid.setHeight("500px"); ). But you also need to take in consideration the parent layout. In my example, the parent layout is a VerticalLayout, then by setting the height to full to this layout will make the tree take all the possible space. Regards.

[mlopezFC]

Artur wrote on 2022-05-18 (comment migrated from the previous website):

Hi Paola, thank you very much for your example!! I was just trying to figure out how to make lazy loading with tree grid, now I also have to make a filter but I don’t really get what flattenElement() method does. I tried to write my own filter just like you did but came across one problem: as my dataProvider has like 1000000 elements and I have to filter the data really quick I deleted flattenElement() method as it is too time consuming and heavy but now I get error each time I reload the page, like that: Assertion error: No child node found with id 27 Can you please tell me what is the flattenElement() method needed for or maybe some other way to make filter with dataProvider work, I don’t really have an idea why my page crushes on reload, thank ypu in advance, looking forward to hearing from you, Best regards, Artur.

[mlopezFC]

Paola De Bartolo wrote on 2022-05-20 (comment migrated from the previous website):

Hello Artur. Please keep in mind that the DepartmentService class is just a mock of a service . The flattenElement method is only a method that helps to simulate a database or rest API call searching for the results. What you need to do is write your own implementation of the filtering having in consideration your backed service.

[mlopezFC]

Berk Ott wrote on 2023-08-18 (comment migrated from the previous website):

Thank you for this Paola! Can you provide what the actual query string looks like? Is there where clause or is it just select Dept , Manager. I have yet to find a complete example for reading data from a database. Much appreciated!

[mlopezFC]

Berk Ott wrote on 2023-08-23 (comment migrated from the previous website):

Oops I just saw the link to GitHub! Thank you!