From 4f3be018cfbeea21fc627edacfd72b199b6ee6a8 Mon Sep 17 00:00:00 2001
From: Melloware <mellowaredev@gmail.com>
Date: Mon, 19 Feb 2024 10:19:32 -0500
Subject: [PATCH] Fix #11452 - 13.0.6 DataTable: LazyDataModel.load gets
 invoked multiple times (#11461)

---
 .../component/datatable/DataTableRenderer.java | 18 ++++++++----------
 .../org/primefaces/model/LazyDataModel.java    | 10 +++++++++-
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/primefaces/src/main/java/org/primefaces/component/datatable/DataTableRenderer.java b/primefaces/src/main/java/org/primefaces/component/datatable/DataTableRenderer.java
index caf2c598d9..847e2a1059 100644
--- a/primefaces/src/main/java/org/primefaces/component/datatable/DataTableRenderer.java
+++ b/primefaces/src/main/java/org/primefaces/component/datatable/DataTableRenderer.java
@@ -1086,7 +1086,6 @@ protected void encodeRows(FacesContext context, DataTable table, int first, int
         String clientId = table.getClientId(context);
         List<SummaryRow> summaryRows = table.getSummaryRows();
         HeaderRow headerRow = table.getHeaderRow();
-        ELContext elContext = context.getELContext();
 
         SortMeta sort = table.getHighestPriorityActiveSortMeta();
         boolean encodeHeaderRow = headerRow != null && headerRow.isEnabled() && sort != null;
@@ -1102,7 +1101,7 @@ protected void encodeRows(FacesContext context, DataTable table, int first, int
 
             table.setRowIndex(i);
 
-            if (encodeHeaderRow && (i == first || !isInSameGroup(context, table, i, -1, sort.getSortBy(), elContext))) {
+            if (encodeHeaderRow && (i == first || !isInSameGroup(context, table, i, -1, sort.getSortBy(), false))) {
                 table.setRowIndex(i);
                 encodeHeaderRow(context, table, headerRow);
             }
@@ -1110,7 +1109,7 @@ protected void encodeRows(FacesContext context, DataTable table, int first, int
             table.setRowIndex(i);
             encodeRow(context, table, clientId, i, columnStart, columnEnd);
 
-            if (encodeSummaryRow && !isInSameGroup(context, table, i, 1, sort.getSortBy(), elContext)) {
+            if (encodeSummaryRow && !isInSameGroup(context, table, i, 1, sort.getSortBy(), i == last - 1)) {
                 table.setRowIndex(i);
                 encodeSummaryRow(context, summaryRows, sort);
             }
@@ -1598,8 +1597,8 @@ protected void encodeSubTable(FacesContext context, DataTable table, SubTable su
     }
 
     protected boolean isInSameGroup(FacesContext context, DataTable table, int currentRowIndex, int step, ValueExpression groupByVE,
-                                    ELContext elContext) {
-
+                                    boolean loadFirstRowOfNextPage) {
+        ELContext elContext = context.getELContext();
         table.setRowIndex(currentRowIndex);
         Object currentGroupByData = groupByVE.getValue(elContext);
 
@@ -1607,11 +1606,10 @@ protected boolean isInSameGroup(FacesContext context, DataTable table, int curre
 
         Object nextGroupByData;
 
-        // in case of a lazy DataTable, the LazyDataModel currently only loads rows inside the current page; we need a small hack here
-        // 1) get the rowData manually for the next row
-        // 2) put it into request-scope
-        // 3) invoke the groupBy ValueExpression
-        if (table.isLazy()) {
+        // An additional check is required to ensure summaryRow will be rendered in case
+        // number of rows of the current page is equals to the number of items in the current group (otherwise, it'll never be rendered)
+        // see #9077
+        if (loadFirstRowOfNextPage && table.isLazy()) {
             Object nextRowData = table.getLazyDataModel().getRowData(nextRowIndex, table.getActiveSortMeta(), table.getActiveFilterMeta());
             if (nextRowData == null) {
                 return false;
diff --git a/primefaces/src/main/java/org/primefaces/model/LazyDataModel.java b/primefaces/src/main/java/org/primefaces/model/LazyDataModel.java
index c172fa7508..612bf7701d 100644
--- a/primefaces/src/main/java/org/primefaces/model/LazyDataModel.java
+++ b/primefaces/src/main/java/org/primefaces/model/LazyDataModel.java
@@ -107,8 +107,16 @@ public T getRowData(String rowKey) {
                         + ", when basic rowKey algorithm is not used [component=%s,view=%s]."));
     }
 
+    /**
+     * Loads a single row for the rowIndex provided.
+     *
+     * @param rowIndex the row index to load
+     * @param sortBy a map with all sort information (only relevant for DataTable, not for eg DataView)
+     * @param filterBy a map with all filter information (only relevant for DataTable, not for eg DataView)
+     * @return the data
+     */
     public T getRowData(int rowIndex, Map<String, SortMeta> sortBy, Map<String, FilterMeta> filterBy) {
-        List<T> loaded = load(rowIndex, rowIndex + 1, sortBy, filterBy);
+        List<T> loaded = load(rowIndex, 1, sortBy, filterBy);
         if (loaded == null || loaded.isEmpty()) {
             return null;
         }