[Bug]: after entering file name, template modal takes ages to load

[maximelehericy]

⚠️ This issue respects the following points: ⚠️

• [X] This is a bug, not a question or a configuration/webserver/proxy issue.
• [X] This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• [X] Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• [X] I agree to follow Nextcloud's Code of Conduct.

Bug description

when creating a new file, after clicking the + and entering the file name, the template modal takes ages to load (about 15s on c.nc.c).

In the meantime nothing happens, and eventually, the popup appears, allowing one to pick a template.

Steps to reproduce

1. go to Files
2. click on + to create a new markdown file for example
3. enter a filename "I love nc30" for example and hit enter
4. wait
5. eventually, the template picker shows up.

Expected behavior

template picker should show up way faster, and/or a loading item should also tell the user something is happening in the background.

Installation method

None

Nextcloud Server version

master

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• [ ] Default user-backend (database)
• [ ] LDAP/ Active Directory
• [ ] SSO - SAML
• [ ] Other

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

c.nc.c

[sorbaugh]

@Pytal maybe we can schedule this?

[susnux]

@sorbaugh this is not a front end bug¹, the real problem is that GET /ocs/v2.php/apps/files/api/v1/templates takes for ages to load even with only few templates. Meaning the template backend suffers performance issues.

¹ Well we should show a loading indicator, maybe even open the dialog but with "loading templates " inside?