Infinite scroll on blocks page

apps/block_scout_web/assets/__tests__/pages/blocks.js

@@ -70,20 +70,6 @@ describe('RECEIVED_NEW_BLOCK', () => {
       { blockNumber: 1, blockHtml: 'test' }
     ])
   })
-  test('on page 2+', () => {
-    const state = Object.assign({}, initialState, {
-      beyondPageOne: true
-    })
-    const action = {
-      type: 'RECEIVED_NEW_BLOCK',
-      msgs: [{
-        blockHtml: 'test'
-      }]
-    }
-    const output = reducer(state, action)
-
-    expect(output.blocks).toEqual([])
-  })
   test('inserts place holders if block received out of order', () => {
     window.localized = {}
     const state = Object.assign({}, initialState, {
@@ -154,3 +140,28 @@ describe('RECEIVED_NEW_BLOCK', () => {
     ])
   })
 })
+
+describe('RECEIVED_NEXT_PAGE', () => {
+  test('with new block page', () => {
+    const state = Object.assign({}, initialState, {
+      loadingNextPage: true,
+      nextPageUrl: '1',
+      blocks: [{ blockNumber: 2, blockHtml: 'test 2' }]
+    })
+    const action = {
+      type: 'RECEIVED_NEXT_PAGE',
+      msg: {
+        nextPageUrl: '2',
+        blocks: [{ blockNumber: 1, blockHtml: 'test 1' }]
+      }
+    }
+    const output = reducer(state, action)
+
+    expect(output.loadingNextPage).toEqual(false)
+    expect(output.nextPageUrl).toEqual('2')
+    expect(output.blocks).toEqual([
+      { blockNumber: 2, blockHtml: 'test 2' },
+      { blockNumber: 1, blockHtml: 'test 1' }
+    ])
+  })
+})

apps/block_scout_web/assets/js/pages/address.js

@@ -356,7 +356,7 @@ if ($addressDetailsPage.length) {
     msg: humps.camelizeKeys(msg)
   }))
 
-  $('[data-selector="transactions-list"]').length && onScrollBottom(function loadMoreTransactions () {
+  $('[data-selector="transactions-list"]').length && onScrollBottom(() => {
     const { loadingNextPage, nextPageUrl, pagingError } = store.getState()
     if (!loadingNextPage && nextPageUrl && !pagingError) {
       store.dispatch({

apps/block_scout_web/assets/js/pages/blocks.js

@@ -1,9 +1,9 @@
 import $ from 'jquery'
 import _ from 'lodash'
-import URI from 'urijs'
 import humps from 'humps'
 import socket from '../socket'
 import { createStore, connectElements } from '../lib/redux_helpers.js'
+import { onScrollBottom } from '../lib/utils'
 import listMorph from '../lib/list_morph'
 
 export const initialState = {
@@ -11,14 +11,15 @@ export const initialState = {
 
   blocks: [],
 
-  beyondPageOne: null
+  loadingNextPage: false,
+  pagingError: false,
+  nextPageUrl: null
 }
 
 export const reducer = withMissingBlocks(baseReducer)
 
 function baseReducer (state = initialState, action) {
   switch (action.type) {
-    case 'PAGE_LOAD':
     case 'ELEMENTS_LOAD': {
       return Object.assign({}, state, _.omit(action, 'type'))
     }
@@ -28,7 +29,7 @@ function baseReducer (state = initialState, action) {
       })
     }
     case 'RECEIVED_NEW_BLOCK': {
-      if (state.channelDisconnected || state.beyondPageOne) return state
+      if (state.channelDisconnected) return state
 
       if (!state.blocks.length || state.blocks[0].blockNumber < action.msg.blockNumber) {
         return Object.assign({}, state, {
@@ -43,6 +44,27 @@ function baseReducer (state = initialState, action) {
         })
       }
     }
+    case 'LOADING_NEXT_PAGE': {
+      return Object.assign({}, state, {
+        loadingNextPage: true
+      })
+    }
+    case 'PAGING_ERROR': {
+      return Object.assign({}, state, {
+        loadingNextPage: false,
+        pagingError: true
+      })
+    }
+    case 'RECEIVED_NEXT_PAGE': {
+      return Object.assign({}, state, {
+        loadingNextPage: false,
+        nextPageUrl: action.msg.nextPageUrl,
+        blocks: [
+          ...state.blocks,
+          ...action.msg.blocks
+        ]
+      })
+    }
     default:
       return state
   }
@@ -88,16 +110,35 @@ const elements = {
       const newElements = _.map(state.blocks, ({ blockHtml }) => $(blockHtml)[0])
       listMorph(container, newElements, { key: 'dataset.blockNumber' })
     }
+  },
+  '[data-selector="next-page-button"]': {
+    load ($el) {
+      return {
+        nextPageUrl: `${$el.hide().attr('href')}&type=JSON`
+      }
+    }
+  },
+  '[data-selector="loading-next-page"]': {
+    render ($el, state) {
+      if (state.loadingNextPage) {
+        $el.show()
+      } else {
+        $el.hide()
+      }
+    }
+  },
+  '[data-selector="paging-error-message"]': {
+    render ($el, state) {
+      if (state.pagingError) {
+        $el.show()
+      }
+    }
   }
 }
 
 const $blockListPage = $('[data-page="block-list"]')
 if ($blockListPage.length) {
   const store = createStore(reducer)
-  store.dispatch({
-    type: 'PAGE_LOAD',
-    beyondPageOne: !!humps.camelizeKeys(URI(window.location).query(true)).blockNumber
-  })
   connectElements({ store, elements })
 
   const blocksChannel = socket.channel(`blocks:new_block`, {})
@@ -109,6 +150,27 @@ if ($blockListPage.length) {
     type: 'RECEIVED_NEW_BLOCK',
     msg: humps.camelizeKeys(msg)
   }))
+
+  onScrollBottom(() => {
+    const { loadingNextPage, nextPageUrl, pagingError } = store.getState()
+    if (!loadingNextPage && nextPageUrl && !pagingError) {
+      store.dispatch({
+        type: 'LOADING_NEXT_PAGE'
+      })
+      $.get(nextPageUrl)
+        .done(msg => {
+          store.dispatch({
+            type: 'RECEIVED_NEXT_PAGE',
+            msg: humps.camelizeKeys(msg)
+          })
+        })
+        .fail(() => {
+          store.dispatch({
+            type: 'PAGING_ERROR'
+          })
+        })
+    }
+  })
 }
 
 export function placeHolderBlock (blockNumber) {

apps/block_scout_web/lib/block_scout_web/controllers/block_controller.ex

@@ -3,9 +3,12 @@ defmodule BlockScoutWeb.BlockController do
 
   import BlockScoutWeb.Chain, only: [paging_options: 1, next_page_params: 3, split_list_by_page: 1]
 
+  alias BlockScoutWeb.BlockView
   alias Explorer.Chain
+  alias Phoenix.View
 
-  def index(conn, params) do
+  def index(conn, %{"type" => "JSON"} = params) do
+    full_options =
       [
         necessity_by_association: %{
           :transactions => :optional,
@@ -13,6 +16,54 @@ defmodule BlockScoutWeb.BlockController do
         }
       ]
       |> Keyword.merge(paging_options(params))
+
+    blocks_plus_one = Chain.list_blocks(full_options)
+    {blocks, next_page} = split_list_by_page(blocks_plus_one)
+
+    next_page_url =
+      case next_page_params(next_page, blocks, params) do
+        nil ->
+          nil
+
+        next_page_params ->
+          block_path(
+            conn,
+            :index,
+            next_page_params
+          )
+      end
+
+    block_type = Keyword.get(full_options, :block_type, "Block")
+
+    json(
+      conn,
+      %{
+        blocks:
+          Enum.map(blocks, fn block ->
+            %{
+              block_number: block.number,
+              block_html:
+                View.render_to_string(
+                  BlockView,
+                  "_tile.html",
+                  block: block,
+                  block_type: block_type
+                )
+            }
+          end),
+        next_page_url: next_page_url
+      }
+    )
+  end
+
+  def index(conn, params) do
+    [
+      necessity_by_association: %{
+        :transactions => :optional,
+        [miner: :names] => :optional
+      }
+    ]
+    |> Keyword.merge(paging_options(%{}))
     |> handle_render(conn, params)
   end
 

apps/block_scout_web/lib/block_scout_web/templates/block/index.html.eex

@@ -14,11 +14,22 @@
           <%= render BlockScoutWeb.BlockView, "_tile.html", block: block, block_type: @block_type %>
         <% end %>
       </span>
+      <div data-selector="loading-next-page" class="tile tile-muted text-center mt-3" style="display: none;">
+        <span class="loading-spinner-small mr-2">
+          <span class="loading-spinner-block-1"></span>
+          <span class="loading-spinner-block-2"></span>
+        </span>
+        <%= gettext("Loading") %>...
+      </div>
+      <div data-selector="paging-error-message" class="alert alert-danger text-center mt-3" style="display: none;">
+        <%= gettext("Error trying to fetch next page.") %>
+      </div>
 
       <%= if @next_page_params do %>
         <%= link(
           gettext("Older"),
           class: "button button-secondary button-sm float-right mt-3",
+          "data-selector": "next-page-button",
           to: block_path(
             @conn,
             :index,

apps/block_scout_web/test/block_scout_web/controllers/block_controller_test.exs

@@ -68,12 +68,15 @@ defmodule BlockScoutWeb.BlockControllerTest do
 
       conn =
         get(conn, block_path(conn, :index), %{
+          "type" => "JSON",
           "block_number" => Integer.to_string(block.number)
         })
 
+      {:ok, %{"blocks" => blocks}} = conn.resp_body |> Poison.decode()
+
       actual_block_ids =
-        conn.assigns.blocks
-        |> Enum.map(& &1.number)
+        blocks
+        |> Enum.map(& &1["block_number"])
         |> Enum.reverse()
 
       assert second_page_block_ids == actual_block_ids