How <rich:dataScroller> calculate how many page link ?

[askkuber]

<rich:dataScroller>

How it calculate page link? What is the logic behind it?

[michpetrov]

I don't understand the question. The scroller knows that table has 60 rows and that it's supposed to display 15 rows at the time so it generates links for 4 pages.

[askkuber]

What if the pagination is server side then how it will calculate because its dynamic ?  I have server side pagination so i changed walk method like this

public void walk(FacesContext context, DataVisitor visitor, Range range, Object argument) {

    boolean reload = false;

    if (null != context && context.getCurrentPhaseId().equals(PhaseId.RENDER_RESPONSE)) {

      reload = true;

    }

    wrappedKeys = new ArrayList<BigInteger>();

    SequenceRange sr = (SequenceRange) range;

    int currentRow = sr.getFirstRow();

    rows = sr.getRows();

    if (currentRow == 0) {

      pageNo = 1;

    } else

      pageNo = (currentRow / rows) + 1;

    totalRecord= createSelectWebSeriveQuery(reload);

    MyBean.setDiscrepenciesResultListLoaded(totalRecord);

    if (!totalRecord.isEmpty()) {

      for (SomeObj item : totalRecord) {

        wrappedKeys.add(item.getId());

        wrappedData.put(item.getId(), item);

        // Once data populated to wrappedKeys and wrappedData call the

        // process method using visitor parameter

        visitor.process(context, item.getId(), argument);

      }

    }

  }

Now issue is that I have 15982 total number of record So total Pages 160

Total Number of record  = 15982

rows = 100

and sr.getFirstRow(); always give FirstRow So this will be like this

if sr.getFirstRow() = 0 then PageNumber=1;

if sr.getFirstRow() = 100 then PageNumber=2;

if sr.getFirstRow() = 200 then PageNumber=3;

........................................................

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if sr.getFirstRow() = 15700 then PageNumber=158;

if sr.getFirstRow() = 15800 then PageNumber=159;

But in last case also sr.getFirstRow() will give 15882(Every time 100 less)

if sr.getFirstRow() = 15882 then PageNumber=159; (While it should be 160 in this case)

   This creating a issue Can you tell me what is wrong the logic ?

[michpetrov]

As far as I recall if you're fetching records lazily then you need to implement your own datamodel. As for the page number 15882 should return 159 (but I don't get why that would ever be the first row).

[askkuber]

Do you mean logic in walk method is wrong as this method change by me for server side pagination.

[michpetrov]

I'm not sure you're referring to. You've said you got 15982 rows (nine hundred) but then you show 15882 (eight hundred) as the number you have an issue with. But no matter what the number is it is the last row, so your getFirstRow() method should never return that number.