Data Pagination - List Page size depending on the device height

[simeatan]

Hi all.
I have a list with quite a few records and data pagination is almost a must for me, speed-wise. It works great. Using NavigationButtons as Pagination Method. Width=100% takes care of the horizontal. A few search boxes and buttons, drop-list on the panel.

How would someone implement a different Page Size value in case of a Data Pagination in List? For example, I'd like to set Page Size = 15 for iphone5, and Page Size = 40 for Nexus10. Could throw in the orientation factor too, but portrait will do it fine. Is there a way to set that value (page size) dynamically, and more important without passing parameters from viewport, bootstrap or something similar. Tried Height=100%, "Control container prevent float=.T." (can't fill the container), with no luck.

Is there a simple solution? I'm getting lost in the responsive design here.
Thanks!
Sime

PS latest patches of AA

[peteconway]

Re: Data Pagination - List Page size depending on the device height

All you are really doing with the Paginate method is to limit the records each call to a reasonable number from the server, the overflow simply scrolls the list to that point off screen, until scrolled into view, as long as you panel card is re sizing OK, then just be a little liberal with the lines per record and it will be fine.

[Davidk]

Re: Data Pagination - List Page size depending on the device height

Do you really want to make a call to the server each time you want a page of data? For an iPhone that a call per 15 rows.

If you were to render your full List... how many rows would it be?

I understand not wanting to render all rows. That would potentially blow up the DOM. Instead you can manage List memory usage and use List Virtualization to render a page... or a few pages... at a time... show as many rows as you like. With this method you can alter the number of rows rendered depending on device and orientation.

Using both Data Pagination and List Virtualization, you can control the number of rows retrieved from the server... and then also control the number of rows rendered. You'd do this if you have a very large number of rows required from the server and also wanted to ensure you managed your DOM successfully.

[simeatan]

Re: Data Pagination - List Page size depending on the device height

Thanks Peter and David! Sorry for the delayed reply - out of town, with no internet on hand.

I think, as Peter pointed out, resizing the panel is where I haven't solved the issue. Haven't gotten into the bootstrap or any other technique to wrap the a5 with. David, combining the data pagination with list virtualization sounds cool but it might be overkill for what I'm doing, especially with my limited knowledge of AA. I had to go with the pagination - there're cca 40,000 records, with many fields to work with.

One new problem I have with the pagination is that I can't seem to be able to move the record pointer together with the page navigation. I use navigation buttons (first, prev next, last) and they work great. I'm able to move back and forth through the pages very quickly. OnSelect a row in the list it shows the right details (from a same table) in the next panel. But if I go to the next page (say 10 rows per page and the selected row jumps from row#13 to row#23) and I do swipe the Detail panel still shows #13's details? Again, the Select works fine. The table is DBF, indexed, but I just want to implement skip +10, using javascript. _listFetchMore needs the list to use FetchMore, not NavButtons. Why doesn't the record pointer/cursor move together with the new page of records, thus not corresponding to the selected row?
I believe something like "skip 10" in Next, "skip -10" in Prev button (maybe I could use _listGetElement somehow?) would help me, short of using xbasic.
Or, even simpler, to programmatically click on the selected row on the list. I'm not aware of any syntax for list. highlighted. select() . I'm making up words here now.
I'm using a DBF, if that matters.