In order to improve the loading speed of Spreadsheet (Extjs+JAVA), all page signatures and first page data are loaded for the first time when entering the table. Next, click on the tabs one by one and request the backend (JAVA) to load the data of the selected tab again.
To request the backend data and load it for the selected tab you can use onAfterSheetShow event which shows the currently opened sheet. In its event handler you can make a data request for the currently selected sheet.
Please take a look at the example: Code Snippet
