docx-js/src/file/xml-components/default-attributes.ts

import { BaseXmlComponent, IContext } from "./base";
import { IXmlableObject } from "./xmlable-object";

export type AttributeMap<T> = { readonly [P in keyof T]: string };

export type AttributeData = { readonly [key: string]: boolean | number | string };
export type AttributePayload<T extends AttributeData> = Record<
    keyof T,
    {
        readonly key: string;
        readonly value?: T[keyof T];
    }
>;

export abstract class XmlAttributeComponent<T extends object> extends BaseXmlComponent {
    protected readonly xmlKeys?: AttributeMap<T>;

    public constructor(private readonly root: T) {
        super("_attr");
    }

    public prepForXml(_: IContext): IXmlableObject {
        const attrs = {};
        Object.keys(this.root).forEach((key) => {
            const value = this.root[key];
            if (value !== undefined) {
                const newKey = (this.xmlKeys && this.xmlKeys[key]) || key;
                // eslint-disable-next-line functional/immutable-data
                attrs[newKey] = value;
            }
        });
        return { _attr: attrs };
    }
}

export class NextAttributeComponent<T extends AttributeData> extends BaseXmlComponent {
    public constructor(private readonly root: AttributePayload<T>) {
        super("_attr");
    }

    public prepForXml(_: IContext): IXmlableObject {
        const attrs = {};
        Object.values(this.root).forEach(({ key, value }) => {
            if (value !== undefined) {
                // eslint-disable-next-line functional/immutable-data
                attrs[key] = value;
            }
        });
        return { _attr: attrs };
    }
}