Function registerExternalTransform

src/data/helper/transform.ts:333–361

(
    externalTransform: ExternalDataTransform
)

const externalTransformMap = createHashMap<ExternalDataTransform, string>();

export function registerExternalTransform(
    externalTransform: ExternalDataTransform
): void {
    externalTransform = clone(externalTransform);
    let type = externalTransform.type;
    let errMsg = '';
    if (!type) {
        if (__DEV__) {
            errMsg = 'Must have a `type` when `registerTransform`.';
        }
        throwError(errMsg);
    }
    const typeParsed = type.split(':');
    if (typeParsed.length !== 2) {
        if (__DEV__) {
            errMsg = 'Name must include namespace like "ns:regression".';
        }
        throwError(errMsg);
    }
    // Namespace 'echarts:xxx' is official namespace, where the transforms should
    // be called directly via 'xxx' rather than 'echarts:xxx'.
    let isBuiltIn = false;
    if (typeParsed[0] === 'echarts') {
        type = typeParsed[1];
        isBuiltIn = true;
    }
    externalTransform.__isBuiltIn = isBuiltIn;
    externalTransformMap.set(type, externalTransform);
}

export function applyDataTransform(
    rawTransOption: DataTransformOption | PipedDataTransformOption,