@loaders.gl/json/dist/lib/encoder-utils/encode-table-row.js

Framework-independent loader for JSON and streaming JSON formats

// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
// Copyright 2022 Foursquare Labs, Inc.
import { getTableRowAsObject } from '@loaders.gl/schema';
import { getRowPropertyObject } from "./encode-utils.js";
// Helpers
/**
 * Encode a row. Currently this ignores properties in the geometry column.
 */
export function encodeTableRow(table, rowIndex, geometryColumnIndex, utf8Encoder) {
    const row = getTableRowAsObject(table, rowIndex);
    if (!row)
        return;
    const featureWithProperties = getFeatureFromRow(table, row, geometryColumnIndex);
    const featureString = JSON.stringify(featureWithProperties);
    utf8Encoder.push(featureString);
}
/**
 * Encode a row as a Feature. Currently this ignores properties objects in the geometry column.
 */
function getFeatureFromRow(table, row, geometryColumnIndex) {
    // Extract non-feature/geometry properties
    const properties = getRowPropertyObject(table, row, [geometryColumnIndex]);
    // Extract geometry feature
    const columnName = table.schema?.fields[geometryColumnIndex].name;
    let featureOrGeometry = columnName && row[columnName];
    // GeoJSON support null geometries
    if (!featureOrGeometry) {
        // @ts-ignore Feature type does not support null geometries
        return { type: 'Feature', geometry: null, properties };
    }
    // Support string geometries?
    // TODO: This assumes GeoJSON strings, which may not be the correct format
    // (could be WKT, encoded WKB...)
    if (typeof featureOrGeometry === 'string') {
        try {
            featureOrGeometry = JSON.parse(featureOrGeometry);
        }
        catch (err) {
            throw new Error('Invalid string geometry');
        }
    }
    if (typeof featureOrGeometry !== 'object' || typeof featureOrGeometry?.type !== 'string') {
        throw new Error('invalid geometry column value');
    }
    if (featureOrGeometry?.type === 'Feature') {
        // @ts-ignore Feature type does not support null geometries
        return { ...featureOrGeometry, properties };
    }
    // @ts-ignore Feature type does not support null geometries
    return { type: 'Feature', geometry: featureOrGeometry, properties };
}