JavaScript Data GridLoad Retry

import {
  GridApi,
  GridOptions,
  IServerSideDatasource,
  ModuleRegistry,
  createGrid,
  enableDevValidations,
} from "ag-grid-community";
import {
  RowGroupingModule,
  ServerSideRowModelApiModule,
  ServerSideRowModelModule,
} from "ag-grid-enterprise";
import { FakeServer } from "./fakeServer";
import { IOlympicData } from "./interfaces";

// Enable extended validations only for development
if (process.env.NODE_ENV !== "production") {
  enableDevValidations();
}

ModuleRegistry.registerModules([
  RowGroupingModule,
  ServerSideRowModelModule,
  ServerSideRowModelApiModule,
]);

let gridApi: GridApi<IOlympicData>;
const gridOptions: GridOptions<IOlympicData> = {
  columnDefs: [
    {
      // demonstrating the use of valueGetters
      colId: "country",
      valueGetter: "data.country",
      rowGroup: true,
      hide: true,
    },
    { field: "sport", rowGroup: true, hide: true },
    { field: "year", minWidth: 100 },
    { field: "gold", aggFunc: "sum" },
    { field: "silver", aggFunc: "sum" },
    { field: "bronze", aggFunc: "sum" },
  ],
  defaultColDef: {
    flex: 1,
    minWidth: 120,
  },
  autoGroupColumnDef: {
    flex: 1,
    minWidth: 280,
    field: "athlete",
  },

  // use the server-side row model
  rowModelType: "serverSide",
  maxConcurrentDatasourceRequests: 1,

  suppressAggFuncInHeader: true,
  purgeClosedRowNodes: true,

  cacheBlockSize: 20,
};

function getServerSideDatasource(server: any): IServerSideDatasource {
  return {
    getRows: (params) => {
      console.log("[Datasource] - rows requested by grid: ", params.request);

      const response = server.getData(params.request);

      // adding delay to simulate real server call
      setTimeout(() => {
        if (response.success) {
          // call the success callback
          params.success({
            rowData: response.rows,
            rowCount: response.lastRow,
          });
        } else {
          // inform the grid request failed
          params.fail();
        }
      }, 1000);
    },
  };
}

function onBtRetry() {
  gridApi!.retryServerSideLoads();
}

function onBtReset() {
  gridApi!.refreshServerSide({ purge: true });
}

const gridDiv = document.querySelector<HTMLElement>("#myGrid")!;
gridApi = createGrid(gridDiv, gridOptions);

fetch("https://www.ag-grid.com/example-assets/olympic-winners.json")
  .then((response) => response.json())
  .then(function (data) {
    // setup the fake server with entire dataset
    const fakeServer = new FakeServer(data);

    // create datasource with a reference to the fake server
    const datasource = getServerSideDatasource(fakeServer);

    // register the datasource with the grid
    gridApi!.setGridOption("serverSideDatasource", datasource);
  });

if (typeof window !== "undefined") {
  // Attach external event handlers to window so they can be called from index.html
  (<any>window).onBtRetry = onBtRetry;
  (<any>window).onBtReset = onBtReset;
}

.example-wrapper {
    display: flex;
    flex-direction: column;
    height: 100%;
}

#myGrid {
    flex: 1 1 auto;
    width: 100%;
}

// This fake server uses http://alasql.org/ to mimic how a real server
// might generate sql queries from the Server-Side Row Model request.
// To keep things simple it does the bare minimum to support the example.
export function FakeServer(allData) {
    alasql.options.cache = false;

    return {
        getData: function (request) {
            const failLoad = document.querySelector('#failLoad').checked === true;
            if (failLoad) {
                return {
                    success: false,
                };
            }

            const results = executeQuery(request);

            return {
                success: true,
                rows: results,
                lastRow: getLastRowIndex(request),
            };
        },
    };

    function executeQuery(request) {
        const sql = buildSql(request);

        console.log('[FakeServer] - about to execute query:', sql);

        return alasql(sql, [allData]);
    }

    function buildSql(request) {
        return (
            selectSql(request) +
            ' FROM ?' +
            whereSql(request) +
            groupBySql(request) +
            orderBySql(request) +
            limitSql(request)
        );
    }

    function selectSql(request) {
        const rowGroupCols = request.rowGroupCols;
        const valueCols = request.valueCols;
        const groupKeys = request.groupKeys;

        if (isDoingGrouping(rowGroupCols, groupKeys)) {
            const rowGroupCol = rowGroupCols[groupKeys.length];
            const colsToSelect = [rowGroupCol.id];

            valueCols.forEach(function (valueCol) {
                colsToSelect.push(valueCol.aggFunc + '(' + valueCol.id + ') AS ' + valueCol.id);
            });

            return 'SELECT ' + colsToSelect.join(', ');
        }

        return 'SELECT *';
    }

    function whereSql(request) {
        const rowGroups = request.rowGroupCols;
        const groupKeys = request.groupKeys;
        const whereParts = [];

        if (groupKeys) {
            groupKeys.forEach(function (key, i) {
                const value = typeof key === 'string' ? "'" + key + "'" : key;

                whereParts.push(rowGroups[i].id + ' = ' + value);
            });
        }

        if (whereParts.length > 0) {
            return ' WHERE ' + whereParts.join(' AND ');
        }

        return '';
    }

    function groupBySql(request) {
        const rowGroupCols = request.rowGroupCols;
        const groupKeys = request.groupKeys;

        if (isDoingGrouping(rowGroupCols, groupKeys)) {
            const rowGroupCol = rowGroupCols[groupKeys.length];

            return ' GROUP BY ' + rowGroupCol.id + ' HAVING count(*) > 0';
        }

        return '';
    }

    function orderBySql(request) {
        const sortModel = request.sortModel;

        if (sortModel.length === 0) return '';

        const sorts = sortModel.map(function (s) {
            return s.colId + ' ' + s.sort.toUpperCase();
        });

        return ' ORDER BY ' + sorts.join(', ');
    }

    function limitSql(request) {
        if (request.endRow == undefined || request.startRow == undefined) {
            return '';
        }

        const blockSize = request.endRow - request.startRow;

        return ' LIMIT ' + blockSize + ' OFFSET ' + request.startRow;
    }

    function isDoingGrouping(rowGroupCols, groupKeys) {
        // we are not doing grouping if at the lowest level
        return rowGroupCols.length > groupKeys.length;
    }

    function getLastRowIndex(request) {
        return executeQuery({ ...request, startRow: undefined, endRow: undefined }).length;
    }
}

<div class="example-wrapper">
    <div style="margin-bottom: 5px">
        <label><input type="checkbox" id="failLoad" /> Make Loads Fail</label>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <button onClick="onBtRetry()">Retry Failed Loads</button>
        &nbsp;&nbsp;&nbsp;&nbsp;
        <button onClick="onBtReset()">Reset Entire Grid</button>
    </div>
    <div id="myGrid"></div>
</div>

export interface IOlympicData {
    athlete: string,
    age: number,
    country: string,
    year: number,
    date: string,
    sport: string,
    gold: number,
    silver: number,
    bronze: number,
    total: number
}