[backend] Pagination in search results does not work

[ptahchiev]

• search for any entity
• a table with search results and pagination appears
• click on the next page or previous page - doesn't work
• change number of shown entities - doesn't work.
• go to last/first page - doesn't work.

[ovitanov]

The paging problem is fixed, but I noticed some other possible issues:

1. In search results for product the 29th item is huge, causing the request to timeout and not update the grid (the request for loading the first 10 items is about 30KB, and the request for items 21-30 is over 10MB by the time it times out)
2. The sorting is local, so it is based only on the items in the current page

[ptahchiev]

I believe what's happening is probably EXTJS is loading ALL the data (from page1 to page 20) and it probably manually trims only the last page to be shown. So loading all the data is slow and stupid. We should do all pagination and sorting on the server. You can pass parameters ?page ?size ?sort so that this happens on the server, and not on the clientside.

[ptahchiev]

I also see that when you change the page-size to 1000 the results shown are still 10. This needs to be fixed and we also need a selenium test for it.

[ovitanov]

Default request timeout in the extjs proxy class is 30s, which means that any request, lasting more than 30s is going to be terminated and as a result the grid will not be updated. If you like I can increase the timeout.
In the case of Product results grid the 29th item is taking ages to load, therefore any page size > 28 (50, 100, 1000) times out