Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Table's (page) emits twice per click on a page of the pagination/pager when implemented as shown in the virtual server scrolling example

See original GitHub issue

I’m submitting a …

[x] bug report => search github for a similar issue or PR before submitting
[ ] feature request
[ ] support request => Please do not submit support request here, post on Stackoverflow or Gitter

Current behavior

When using the pager/pagination of a datatable configured for virtual server-side paging as seen here http://swimlane.github.io/ngx-datatable/#virtual-paging https://github.com/swimlane/ngx-datatable/blob/master/demo/paging/paging-virtual.component.ts the (page) emits twice per click. Following the simplified stacktraces:

call DataTableBodyComponent.onFooterPage:6005 DatatableComponent.html:67 DataTableFooterComponent.html:32 DataTablePagerComponent.selectPage:6707 DataTablePagerComponent.html:23
call DataTableBodyComponent.onBodyPage:5977 DatatableComponent.html:47 DataTableBodyComponent.updatePage:4381 DataTableBodyComponent.onBodyScroll:4362 ScrollerComponent.updateOffset:4862 DataTableBodyComponent.html:21

It could be that the second call is provoked by the modification of the bound page object in setPage in line 54,55 of paging-virtual.component.ts

Expected behavior

Either (page) emits only once during one roundtrip or the example (paging-virtual.component.ts) should be adapted either to contain a note concerning the second call or code that prevents this call to query the service again - this might be similar to the cache, but could rely on the (previously) passed pageinfo object to guard against duplicate calls

Reproduction of the problem See here for the issue - the calls of ‘setPage’ are being logged into the console. http://plnkr.co/edit/hcmOYgExj01h0xKtMqXy?p=preview

What is the motivation / use case for changing the behavior? Activating virtual server side scrolling resulting in twice as many calls to the server by default could by problematic.