Grist Widget API - Get column names and types?

jarek · September 25, 2024, 1:29pm

Officially it is not supported yet. The assumption is that a custom widget should know very little about the table it is used on. The dependency is inverted here, widget should inform Grist what columns it expects and Grist should map those columns back. You can read more about column mappings here Custom - Grist Help Center

But if you really need to get this information, you can use general API exposed to widgets and just query for the metdata. Here is an example how the Calendar widget is doing it:

github.com

gristlabs/grist-widget/blob/2c440a23ebe8c0b70606568a35382b9b034ccfcf/calendar/page.js#L778


      
          }
          
          function isZeroTime(date) {
            return date.getHours() === 0 && date.getMinutes() === 0 && date.getSeconds() === 0;
          }
          
          // We have no good way yet to get the type of a mapped column when multiple types are allowed. We
          // get it via the metadata tables instead. There is no good way to know when a column's type is
          // changed, so we skip that for now.
          // TODO: Drop all this once the API can tell us column info.
          class ColTypesFetcher {
            // Returns array of column records for the array of colIds.
            static async getTypes(tableId, colIds) {
              const tables = await grist.docApi.fetchTable('_grist_Tables');
              const columns = await grist.docApi.fetchTable('_grist_Tables_column');
              const fields = Object.keys(columns);
              const tableRef = tables.id[tables.tableId.indexOf(tableId)];
              return colIds.map(colId => {
                const index = columns.id.findIndex((id, i) => (columns.parentId[i] === tableRef && columns.colId[i] === colId));
                if (index === -1) { return null; }
                return Object.fromEntries(fields.map(f => [f, columns[f][index]]));