Document's editor : performance problem when adding/deleting a field

[JoelleDosimont]

Bug description:

In some records, the addition of fields takes too many seconds. It's the same when you delete them. It happens when adding a field that already exist in the record (duplicate of an existing field).
Ex. : try to add import the ISBN 0844741698 from Library of Congress and try to add an identifiers (with Firefox, my test takes approx. 15 seconds).

Expected behavior:

The addition/deletion of a field should be as quick as possible.

Steps to Reproduce:

1. Import the following ISBN 0844741698 from Library of Congress
2. Add an identifier
3. See that it's really slow

Context

Server:

• production: bib.rero.ch or ils.bib.uclouvain.be
• test: bib.test.rero.ch
• dev: ilsdev.test.rero.ch
• dev test : ils.test.rero.ch

Version:

v1.10.0

Browser:

Firefox: version 99.0.1

[zannkukai]

The cause seems the asynchronous validation of the form.
Each time a field is added/deleted, the complete form is validate --> all fields are validated.
If some validators are linked to HTTP checks (asyncValidator) this will cause some performance issue.

[jma]

This is linked to the number of initial value for the arrays. Here is a pure ngx-formly example:
https://stackblitz.com/edit/angular-9znuyr?file=src%2Fapp%2Fapp.component.ts,src%2Fassets%2Fjson-schema%2Farrays.json,src%2Fapp%2Farray.type.ts.

Commenting the line 45 make the editor quite fast. I have ask the formly authors on the following gitter room:
https://gitter.im/formly-js/ng2-formly