lifecycle hooks not working in Collections with draft/publish-System

[pointout]

Describe the bug
I am using lifecycle hooks in models to update fields and create the content for my own slug fields. This works, if the draft-System is off. But when I activate the draft system, data.fieldname is undefined.

Steps to reproduce the behavior

1. Turn off the draft-system for a collection
2. Change data and save them
3. The lifecacle hooks beforeUpdate and beforeCreate are working as expected
4. Turn on the draft-system for the collection
5. unpublish or edtit fields
6. The field are not changed correctly by lifecycle hook, but getting undefined.

Code snippets
/api/product/models/product.js

'use strict';
const slugify = require('slugify');

const mySlugify = (slug) => { 
  return (
    slugify(slug, { 
      remove:/[*+~.(){}\[\]\\/'"!:@,]/g, 
      lower:true 
    })
  );
};

/**
 * Lifecycle callbacks for the `product` model.
 */

module.exports = {

  lifecycles: {
    async beforeCreate(data) {
 
      if (!data.name_en) {
        data.name_en = data.name_de;
      }
      data.slug_de = mySlugify(data.name_de + '-' + data.orderno);
      data.slug_en = mySlugify(data.name_en + '-' + data.orderno);

    },

    async beforeUpdate (params,data) {
      console.log(data);

      if (!data.name_en) {
        data.name_en = data.name_de;
      }
      data.slug_de = mySlugify(data.name_de + '-' + data.orderno);
      data.slug_en = mySlugify(data.name_en + '-' + data.orderno);
      
    }
  }
};

without draft-system:

with daft-system:

In another collection doing the same, data.name_de is logged as undefined, but there is a string in that field.

System

• Node.js version: v12.18.4
• NPM version: 6.14.6
• Strapi version: 3.2.3
• Database: sqlite
• Operating system: Windows 10 Pro

[pointout]

If I empty the name_en and save, the data is correct (name_de in name_en field and Slug-fields created) after refreshing the page.
If I unpublish, the Slug-fields get "undefined-undefined". That is not changing after publishing and/or refreshing the page.

[derrickmehaffy]

I believe I see the problem, during an update not all the data is sent, only what has changed.

In the case of publish/unpublish all that is changing is the published_at your code is making the assumption that if a field is not in the data object it's injecting something (not sure why that is undefined).

This code here:

if (!data.name_en) {
        data.name_en = data.name_de;
      }

If all you do is unpublish something, then both data.name_en and data.name_de are undefined because only the published_at is changed. Effectively whats being done here is the equivalent of a REST PATCH request and not a PUT request.

The difference between the two is a PATCH only includes what's changed where as a PUT would typically include everything.

Breaking down this image

1. I created a new article
2. I published that article
3. I edited the title
4. I unpublished that article

Each of the changes made in 2 through 4 are effective PATCH requests (Strapi doesn't have a PATCH method, and the PUT method acts like it). I don't have a good solution to your case unless you know one of the fields will always have a value, and in that case you can pull the ID from the beforeUpdate params option and run a strapi.query('product').findOne({ id: params.id }) and adjust the data from there.

Something like this, where in this case I unpublished the article but was still able to fetch the data

[derrickmehaffy]

As a side point while this looks like a bug, in this case it's not and is intended. So I'm going to mark this as closed though I do encourage you to respond if you need more information. In the future if possible can you open up a discussion on our Forum if you aren't sure if it's a bug? This makes it easier to handle issues that are generally questions. Thank you!

[lauriejim]

This issue has been mentioned on Strapi Community. There might be relevant details there:

https://forum.strapi.io/t/reload-data-after-saving-update/548/1