salix/modules/entry/back/models/entry.js

const LoopBackContext = require('loopback-context');
module.exports = Self => {
    require('../methods/entry/filter')(Self);
    require('../methods/entry/getEntry')(Self);
    require('../methods/entry/getBuys')(Self);
    require('../methods/entry/importBuys')(Self);
    require('../methods/entry/importBuysPreview')(Self);
    require('../methods/entry/lastItemBuys')(Self);
    require('../methods/entry/entryOrderPdf')(Self);
    require('../methods/entry/addFromPackaging')(Self);
    require('../methods/entry/addFromBuy')(Self);

    Self.observe('before save', async function(ctx, options) {
        if (ctx.isNewInstance) return;

        const changes = ctx.data || ctx.instance;
        const orgData = ctx.currentInstance;

        const observation = changes.observation || orgData.observation;
        const hasChanges = orgData && changes;
        const observationChanged = hasChanges
         && orgData.observation != observation;

        if (observationChanged) {
            let tx;
            const myOptions = {};

            if (typeof options == 'object')
                Object.assign(myOptions, options);

            if (!myOptions.transaction) {
                tx = await Self.beginTransaction({});
                myOptions.transaction = tx;
            }

            try {
                const loopbackContext = LoopBackContext.getCurrentContext();
                const userId = loopbackContext.active.accessToken.userId;
                const id = changes.id || orgData.id;
                const entry = await Self.app.models.Entry.findById(id, null, myOptions);
                await entry.updateAttribute('observationEditorFk', userId, myOptions);
                if (tx) await tx.commit();
            } catch (e) {
                if (tx) await tx.rollback();
                throw e;
            }
        }
    });
};