One-way data sync between Coda tables

coda_one_way_sync.js

CodaAPI.authenticate('abcd1234-efgh-5678-ijkl-1234mnop5678');  // Replace with your token.

SOURCE_TABLES = [
  {
    doc: 'TO UPDATE',
    table: 'Source Table',
  },
  // Add more as needed.
];
TARGET_TABLE = {
  doc: 'TO UPDATE',
  table: 'Target Table',
};
TARGET_TABLE_SOURCE_ROW_COLUMN = 'Source Row URL';

/** Run me! */
function oneWaySync() {
  for each (var source in SOURCE_TABLES) {     //If you are using the V8 runtime delete "each" from this line
    syncSpecificTable(source, TARGET_TABLE);
  }
}

// TODO: handle pagination for syncing source tables with >500 items.
function syncSpecificTable(source, target) {
  // Get info on the source and target tables.
  var sourceTable = CodaAPI.getTable(source.doc, source.table);
  var targetTable = CodaAPI.getTable(target.doc, target.table);
  Logger.log('::::: Syncing "%s" => "%s"...', sourceTable.name, targetTable.name);

  // Find which columns we have to sync.
  var sourceColumns = CodaAPI.listColumns(source.doc, source.table).items.map(function(item) { return item.name; });
  var targetColumns = CodaAPI.listColumns(target.doc, target.table).items.map(function(item) { return item.name; });
  var commonColumns = intersection(sourceColumns, targetColumns);
  Logger.log('Syncing columns: %s', commonColumns.join(', '));
  
    // Pull down all the rows in the source table.
  var sourceRows = CodaAPI.listRows(source.doc, source.table, {limit: 500, useColumnNames: true}).items;
  Logger.log('Source table has %s rows', sourceRows.length);

  // Upsert all rows in the source table into the target table.
  var upsertBodyRows = sourceRows.map(function(row) {
    var cells = commonColumns.map(function(colName) {
      return {
        column: colName,
        value: row.values[colName],
      };
    });
    // Add a URL to the source row in the target, table, which will also be used as the upsert key.
    cells.push({column: TARGET_TABLE_SOURCE_ROW_COLUMN, value: row.browserLink})
    return {cells: cells};
  });
  CodaAPI.upsertRows(target.doc, target.table, {rows: upsertBodyRows, keyColumns: [TARGET_TABLE_SOURCE_ROW_COLUMN]});
  Logger.log('Updated %s!', targetTable.name);
}

function intersection(a, b) {
  var result = [];
  for each (var x in a) {         //If you are using the V8 runtime delete "each" from this line
    if (b.indexOf(x) !== -1) {
      result.push(x);
    }
  }
  return result;
}