Lotus Domino: View pagination on web - view

Question

I read on many forums about how to implement a solution for view pagionation, but I didn't solve it.
I created $$ViewTemplateDefault containing some personalized hotspotbuttons for Next, Previous and a text field $$ViewBody. ( or, alternatively, an embedded view ).
Any tips and help will be really appreciated.
I will explain in a couple words, just to be clear:
So, initially: the first 30 lines will appear => in a right corner: Page 1.
If Next is clicked => the next 30 lines => Page 2. and so on.

Answer 1

Here is a working solution for categorized views too. It calculates the current page number based on the previous page number and uses cookies.
Add to your form a Path-Thru HTML text <span id="pageNumber"></span > for the page number:
and add following code to form's onLoad event as Web/JavaScript:
function getURLParameter(parameter) {
return decodeURIComponent((new RegExp('[?|&]' + parameter + '=' + '([^&;]+?)(&|#|;|$)').exec(location.search) || [, ""])[1].replace(/\+/g, '%20')) || null;
}
function getCookie(cname) {
var name = cname + "=";
var ca = document.cookie.split(';');
for(var i=0; i<ca.length; i++) {
var c = ca[i].trim();
if (c.indexOf(name)==0) return c.substring(name.length,c.length);
}
return "";
}
function compareStart(start1, start2) {
var list1 = start1.split(".");
var list2 = start2.split(".");
for (i=0; i <100; i++) {
var value1 = list1[i];
var value2 = list2[i];
if (value1 == null) {
return value2 == null ? 0 : -1;
} else if (value2 == null) {
return 1;
}
value1 = Math.round(value1);
value2 = Math.round(value2);
if (value1 !== value2) {
return value1 < value2 ? -1 : 1;
}
}
}
var start = getURLParameter("Start");
var page = "1";
if (start == null || start === "1") {
window.name = Math.floor((Math.random()*10000)+1);
start = "1";
} else {
page = getCookie("page" + window.name);
var oldStart = getCookie("start" + window.name);
page = Math.round(page) + compareStart(start, oldStart);
}
document.getElementById('pageNumber').innerHTML = page;
document.cookie = "page" + window.name + "=" + page;
document.cookie = "start" + window.name + "=" + start;
How does it work?
The commands #DbCommand("Domino"; "ViewNextPage") and #DbCommand("Domino"; "ViewPreviousPage") return an URL with parameter "&Start=". This is the row number in view where the current page starts. For categorized views they return a hierarchical number like "&Start=1.2.4.2". That means that the view starts at the first main topic, subtopic 2, subsubtopic 4, document 2.
This parameter "&Start=" gives us the possibility to recognize if user pressed "prev" or "next": we just compare the URL "&Start=" parameter of current and former page.
For that, we have to remember the URL "&Start=" parameter and put it into a cookie "start".
We also need to save the current page number. We put it into a cookie "page".
At onload event we calculate the current page number based on previous page number:
if "&Start=" parameter is larger now then we add 1
if "&Start=" parameter is smaller now then we subtract 1
if "&Start=" parameter didn't change then we keep the former value
If "&Start=" parameter is empty we know we are on page 1.
Here is one other thing we have to deal with: cookies are saved per user session not per browser tab. That means, if we have two views open in browser same cookies "start" and "page" would be used. To avoid that, we have to add to cookie name something tab specific. I use for that a random four digit number and save it in window.name which is tab specific.

Answer 2

I understand your question that you have a working form $$ViewTemplateDefault and now looking for a possibility to show the current page number "Page nn" in that form.
I assume that you use #DbCommand("Domino"; "ViewNextPage") for getting next page and #DbCommand("Domino"; "ViewPreviousPage") for getting previous page.
Those next and prev functions working the way that always one document will "overlap". If you have 30 lines per page and click next, then last document will be first in next page and next 29 show up in addition. You can watch that in used URL parameter "&Start=": 1 ... 30 ... 59 ... 88 ...
Knowing this you can count the current page number this way:
_start := #ToNumber(#Replace(#UrlQueryString("start"); ""; "1"));
_count := #ToNumber(#Replace(#UrlQueryString("count"); ""; "30")) - 1;
#Integer((#ToNumber(_start) / _count) + 1)
Be aware that this will work for non-categorized and non-collapsible views only.
A more sophisticated solution you can find here. It has additional features like GoTo page and Documents per page.
If you have the chance for your project then use XPages instead. You can do pagination much easier as it is available "out of the box".
Update:
You won't find a reasonable solution for categorized views. If you don't want to use Domino Data/Access Services REST API you have to live with the Domino view URL parameters (look here for "OpenView"). You aren't able to tell from "&Start=" or any other parameter on which page you are currently on.
The easiest way to get a good working pagination is using XPages. Hope you are allowed to use it in your project...