Merge pull request #21 from uktrade/feature/pagination

chore:enhance pagination handling for search results

orp/orp_search/public_gateway.py

@@ -1,12 +1,16 @@
 import logging
 
+from typing import Tuple
+
 import pandas as pd
 import requests  # type: ignore
 
 from jinja2 import Template
 from orp_search.config import SearchDocumentConfig
 from orp_search.dummy_data import get_construction_data_as_dataframe
 
+from django.core.paginator import InvalidPage, Paginator
+
 logger = logging.getLogger(__name__)
 
 
@@ -35,20 +39,40 @@ def _build_like_conditions(self, field, terms):
         """
         return " OR ".join([f"{field} LIKE '%{term}%'" for term in terms])
 
-    def paginate_results(self, config: SearchDocumentConfig, results):
+    def paginate_results(
+        self, config: SearchDocumentConfig, results, context
+    ) -> Tuple[dict, Paginator]:
         """
-        Paginates the search results.
+        Paginates the given search results based on the provided configuration.
 
-        Args:
-            results (list): The search results to paginate.
+        Arguments:
+         config (SearchDocumentConfig): Configuration parameters for search,
+                                        including pagination limits.
+         results: A collection of search results to be paginated.
+         context: A dictionary containing context data which will be updated
+                  with pagination details.
 
         Returns:
-            list: The paginated search results.
-            count: Total number of pages from results
+         A tuple containing:
+          - Updated context dictionary with pagination information.
+          - Paginator instance used for paginating the results.
+
+        The context dictionary is updated with the following keys:
+         is_paginated: A boolean indicating if the results span multiple pages.
+         reports: The paginated results for the current page.
+         paginator: The Paginator instance.
+         page_obj: The current page of results.
         """
-        start = (config.offset - 1) * config.limit
-        end = start + config.limit
-        return results[start:end]
+        paginator = Paginator(results, config.limit)
+        try:
+            paginated_reports = paginator.page(config.offset)
+        except InvalidPage:
+            paginated_reports = paginator.page(1)
+        context["is_paginated"] = paginator.num_pages > 1
+        context["reports"] = paginated_reports
+        context["paginator"] = paginator
+        context["page_obj"] = paginated_reports
+        return context, paginator
 
     def calculate_total_pages(self, config, results_count):
         """
@@ -61,6 +85,7 @@ def calculate_total_pages(self, config, results_count):
         Returns:
             int: The total number of pages.
         """
+
         if config.limit <= 0:
             raise ValueError("limit must be greater than 0")
         return (results_count + config.limit - 1) // config.limit

orp/orp_search/views.py

@@ -174,32 +174,40 @@ def search(request: HttpRequest) -> HttpResponse:
     # on the landing page.
 
     if search_results:
-        paginated_search_results = public_gateway.paginate_results(
-            config, search_results
-        )
-        logger.info(
-            "paginated search results after paginate: %s",
-            paginated_search_results,
+        context, paginator = public_gateway.paginate_results(
+            config, search_results, context
         )
 
+        # Initialize a list to hold all results from all pages
+        paginated_search_results = []
+
+        # Iterate over each page
+        for page_num in paginator.page_range:
+            # Get the page
+            page = paginator.page(page_num)
+            # Add the objects of the current page to the aggregate list
+
+            for result in page.object_list:
+                paginated_search_results.append(
+                    {
+                        "id": result["id"],
+                        "title": result["title"],
+                        "publisher": result["publisher"],
+                        "description": (
+                            result["description"][:100] + "..."
+                            if len(result["description"]) > 100
+                            else result["description"]
+                        ),
+                        "date_issued": result["date_issued"],
+                        "date_modified": result["date_modified"],
+                        "document_type": result["type"],
+                        "regulatory_topics": result["regulatory_topics"].split(
+                            "\n"
+                        ),
+                    }
+                )
+
         # We can use the following code to filter the search_results list:
-        paginated_search_results = [
-            {
-                "id": result["id"],
-                "title": result["title"],
-                "publisher": result["publisher"],
-                "description": (
-                    result["description"][:100] + "..."
-                    if len(result["description"]) > 100
-                    else result["description"]
-                ),
-                "date_issued": result["date_issued"],
-                "date_modified": result["date_modified"],
-                "document_type": result["type"],
-                "regulatory_topics": result["regulatory_topics"].split("\n"),
-            }
-            for result in paginated_search_results
-        ]
         context["results_count"] = len(paginated_search_results)
     else:
         paginated_search_results = []