export function makeSeriesEncodeForNameBased()

in src/data/helper/sourceHelper.ts [192:284]
58 lines of code
24 McCabe index (conditional complexity)

export function makeSeriesEncodeForNameBased(
    seriesModel: SeriesModel,
    source: Source,
    dimCount: number
): SeriesEncodeInternal {
    const encode: SeriesEncodeInternal = {};

    const datasetModel = querySeriesUpstreamDatasetModel(seriesModel);
    // Currently only make default when using dataset, util more reqirements occur.
    if (!datasetModel) {
        return encode;
    }

    const sourceFormat = source.sourceFormat;
    const dimensionsDefine = source.dimensionsDefine;

    let potentialNameDimIndex;
    if (sourceFormat === SOURCE_FORMAT_OBJECT_ROWS || sourceFormat === SOURCE_FORMAT_KEYED_COLUMNS) {
        each(dimensionsDefine, function (dim, idx) {
            if ((isObject(dim) ? dim.name : dim) === 'name') {
                potentialNameDimIndex = idx;
            }
        });
    }

    type IdxResult = { v: number, n: number };

    const idxResult = (function () {

        const idxRes0 = {} as IdxResult;
        const idxRes1 = {} as IdxResult;
        const guessRecords = [];

        // 5 is an experience value.
        for (let i = 0, len = Math.min(5, dimCount); i < len; i++) {
            const guessResult = doGuessOrdinal(
                source.data, sourceFormat, source.seriesLayoutBy,
                dimensionsDefine, source.startIndex, i
            );
            guessRecords.push(guessResult);
            const isPureNumber = guessResult === BE_ORDINAL.Not;

            // [Strategy of idxRes0]: find the first BE_ORDINAL.Not as the value dim,
            // and then find a name dim with the priority:
            // "BE_ORDINAL.Might|BE_ORDINAL.Must" > "other dim" > "the value dim itself".
            if (isPureNumber && idxRes0.v == null && i !== potentialNameDimIndex) {
                idxRes0.v = i;
            }
            if (idxRes0.n == null
                || (idxRes0.n === idxRes0.v)
                || (!isPureNumber && guessRecords[idxRes0.n] === BE_ORDINAL.Not)
            ) {
                idxRes0.n = i;
            }
            if (fulfilled(idxRes0) && guessRecords[idxRes0.n] !== BE_ORDINAL.Not) {
                return idxRes0;
            }

            // [Strategy of idxRes1]: if idxRes0 not satisfied (that is, no BE_ORDINAL.Not),
            // find the first BE_ORDINAL.Might as the value dim,
            // and then find a name dim with the priority:
            // "other dim" > "the value dim itself".
            // That is for backward compat: number-like (e.g., `'3'`, `'55'`) can be
            // treated as number.
            if (!isPureNumber) {
                if (guessResult === BE_ORDINAL.Might && idxRes1.v == null && i !== potentialNameDimIndex) {
                    idxRes1.v = i;
                }
                if (idxRes1.n == null || (idxRes1.n === idxRes1.v)) {
                    idxRes1.n = i;
                }
            }
        }

        function fulfilled(idxResult: IdxResult) {
            return idxResult.v != null && idxResult.n != null;
        }

        return fulfilled(idxRes0) ? idxRes0 : fulfilled(idxRes1) ? idxRes1 : null;
    })();

    if (idxResult) {
        encode.value = [idxResult.v];
        // `potentialNameDimIndex` has highest priority.
        const nameDimIndex = potentialNameDimIndex != null ? potentialNameDimIndex : idxResult.n;
        // By default, label uses itemName in charts.
        // So we don't set encodeLabel here.
        encode.itemName = [nameDimIndex];
        encode.seriesName = [nameDimIndex];
    }

    return encode;
}