Add a custom per-user setting in a plugin

documentation developers
1

I just went through this process and experienced a bunch of trial and error, so I thought I’d document my findings to help the next developer to come along.

The things I needed:

  • Register your custom field type (mine was boolean, default is string)

    # plugin.rb
User.register_custom_field_type 'my_preference', :boolean

  • Register that the custom field should be editable by users. Syntax matches that of params.permit(...)

    # plugin.rb
register_editable_user_custom_field :my_preference # Scalar type (string, integer, etc.)
register_editable_user_custom_field [:my_preference , my_preference : []] # For array type
register_editable_user_custom_field [:my_preference,  my_preference : {}] # for json type

  • Add them to the fields serialized with the CurrentUserSerializer

    # plugin.rb
DiscoursePluginRegistry.serialized_current_user_fields << 'my_preference'

  • Create a component to display your user preference

    // assets/javascripts/discourse/templates/components/my-preference.hbs
<label class="control-label">My custom preferences!</label>
{{preference-checkbox labelKey="my_plugin.preferences.key" checked=user.custom_fields.my_preference}}

  • Connect that component to one of the preferences plugin outlets (mine was under ‘interface’ in the user preferences)

    # assets/javascripts/discourse/connectors/user-preferences-interface/my-preference.hbs
{{my-preference user=model}}

  • Ensure ‘custom fields’ are saved on that preferences tab

    import { withPluginApi } from 'discourse/lib/plugin-api'

export default {
  name: 'post-read-email',
  initialize () {
     withPluginApi('0.8.22', api => {

       api.modifyClass('controller:preferences/emails', {
         actions: {
           save () {
             this.get('saveAttrNames').push('custom_fields')
             this._super()
           }
         }
       })

     })
  }
}
31 Likes
2

Nice! I attempted the same in https://github.com/mozilla/discourse-post-read-email and arrived at almost the same result.

My only differences were I didn’t hunt down User.register_custom_field_type and so used my own ugly workaround. (I’ll switch to register_custom_field_type when I get the chance.)

And I think I came up with a slightly neater solution for saving the field, I patch the preferences controller to save custom fields alongside everything else, so the field is saved when the “Save” button is clicked, rather than when it’s toggled:

import { withPluginApi } from 'discourse/lib/plugin-api'

export default {
  name: 'post-read-email',
  initialize () {
     withPluginApi('0.8.22', api => {

       api.modifyClass('controller:preferences/emails', {
         actions: {
           save () {
             this.saveAttrNames.push('custom_fields')
             this._super()
           }
         }
       })

     })
  }
}

This should work for all preferences controllers, as they all seem to use saveAttrNames.

10 Likes
3

As a follow-up here, it turns out that inline-edit-checkbox is available only in the adminjs package, meaning this is currently Bad Advice™. I’ve resorted to using the method suggested above alongside the preference-checkbox component

{{preference-checkbox labelKey="my_plugin.preferences.key" checked=model.custom_fields.my_field}}

which works for all users.

Also, @LeoMcA, I had to modify your preferences hack slightly to work with the interface page since saveAttrNames was a computed property there.

this.get('saveAttrNames').push('custom_fields')
5 Likes
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Per https://github.com/discourse/discourse/commit/4382fb5facb035f5b414c6c7257dc828327a57c7, custom fields must now be added to a whitelist to allow editing by users. All that is needed is a single line in plugin.rb:

register_editable_user_custom_field :my_field

@gdpelican @LeoMcA I have updated the OP with this extra step, and also pulled in the comments from your second and third posts. Please feel free to update anything else you feel is necessary.

8 Likes
5

Perfect, thanks for this - I had fixing discourse-post-read-email on my todolist after last week’s security commit, and this makes it a whole lot easier!

Question (which may belong in a seperate post):

Will this serialize the custom field as an array, even if it only has a single element in it? I’ve been having to use the following pattern in a seperate plugin, so that:

user.custom_fields["field1"] = [ :item ]
user.save_custom_fields

becomes:

Array(user.custom_fields["field1"])
> [ :item ]

rather than:

user.custom_fields["field1"]
> :item
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6

This change only deals with saving custom fields, so I don’t think it will affect how they are serialized.

That said, I do know that there are a lot of weird edge cases relating to custom fields which we are hoping to address in a few weeks time (after 2.1 is released). What you describe above looks like one of those weird cases that we need to improve.

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Note that if the user custom field is a JSON string, you need to include the keys, or an empty hash (if the keys are dynamic), for it to be permitted, e.g.

register_editable_user_custom_field geo_location: {}
3 Likes
8

hm, in a slight pickle actually. If the custom field is JSON, in order to save it, you need to pass a hash, i.e.

register_editable_user_custom_field geo_location: {}

will permit

{"custom_fields"=>{"geo_location"=>{"lat"=>"-37.7989239", "lon"=>"144.8929753", "address"=>"Barkly Street, Footscray, City of Maribyrnong, Greater Melbourne, Victoria, 3011, Australia", "countrycode"=>"au", "city"=>"", "state"=>"Victoria", "country"=>"Australia", "postalcode"=>"3011", "boundingbox"=>["-37.7989854", "-37.7988961", "144.8928258", "144.8931743"], "type"=>"tertiary"}}>

However, if the param is empty (e.g. the user clears the field), the custom_field is interpreted as a string

{"custom_fields"=>{"geo_location"=>"{}"}}

and is not permitted.

There isn’t an easy way around this in the current structure, i.e. the way user_params are added to in the users_controller

permitted << { custom_fields: User.editable_user_custom_fields }

Unless I’m missing something, perhaps some additional provision needs to be made for user_custom_fields that are typecast as JSON?

1 Like
9

I had a similar problem with arrays, not sure if the same will work for JSON. To allow an empty array, you have to permit ‘scalar’ values as well as an array:

register_editable_user_custom_field :geo_location
register_editable_user_custom_field geo_location: []

Or if you’re feeling fancy it can be combined into one line:

register_editable_user_custom_field [ :geo_location, geo_location: [] ]

This is the same behaviour as params.permit(...), so I hesitate to call it a bug. Maybe we can call it a ‘quirk’ :wink:

Let me know if that approach works for JSON - if not we can work out another solution

6 Likes
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:facepalm: of course. Just add another. It’s been a long day. Thanks!

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11

Visiting this again, it feels like there are too many steps here for something that the core plugin system has a command for. On the backend, I have to write the following to make this go:

# plugin.rb
register_editable_user_custom_field :my_setting
User.register_custom_field_type 'my_setting', :boolean
DiscoursePluginRegistry.serialized_current_user_fields << 'my_setting'

but I feel like I should be able to do this:

# plugin.rb
register_editable_user_custom_field :my_setting, :boolean

You could even avoid people running into that nasty array snag by making the plugin system support the following cases:

register_editable_user_custom_field :my_setting, :array
register_editable_user_custom_field :my_setting, :object

@david

10 Likes
12

This is a very helpful post laying out a straight forward example of setting up a user custom field. Is there anything similar for helping guide through a simple topic custom field? I am trying to work through it here:

But I haven’t gotten it to work quite yet. I would really appreciate any help on it.

1 Like
14

David,

This doesn’t seem to work anymore?

We have been using:

  register_editable_user_custom_field [:geo_location,  geo_location: {}] if defined? register_editable_user_custom_field
  register_editable_user_custom_field geo_location: {} if defined? register_editable_user_custom_field

to allow the saving of a json object in a user custom field, but this is now preventing sites from rebuilding!

We have been using this for some time.

The error we are getting during build is:

ArgumentError: wrong number of arguments (given 0, expected 1)
/var/www/discourse/lib/plugin/instance.rb:170:in `register_editable_user_custom_field'
/var/www/discourse/plugins/discourse-locations/plugin.rb:95:in `block in activate!'

To add to the confusion, this appears to work in development, but only fails during a Production build.

If removed, the site will build but the user custom field will not save and fails silently.

I don’t see this is has changed in years?:

Is a new version of Rails blocking this now?

2 Likes
15

@Falco could this be Ruby 3.x related?

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16

FYI I have 2.7.1 installed locally for development (oops) … fixing that now.

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Yes, it’s definitely Ruby 3.1.x related. It works well on 2.7.x.

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I have the plugin installed and enabled with default settings in my local env with the current Ruby, how can I trigger the error?

1 Like
19

Well, that’s the thing. rbenv is not allowing me to install Ruby past 3.0.2 and in development (? what am I missing?) I’m unable to trigger the error in development. But as soon as you try to build a current tests-passed instance with the Locations Plugin on the production_fixes branch (ignore the name, it’s broken).

1 Like
20

It’s 3.1.3 btw. If you are open to suggestions, asdf works great for me.

Cool, will try it.

2 Likes
21

Sorry, I think I’ve actually killed the build error on that branch. I didn’t think it would work, but this, appears to at least build, just testing the functionality now:

It appears if you use this trick:

 register_editable_user_custom_field [:geo_location,  geo_location: {}] if defined? register_editable_user_custom_field

suggested by David above, it works?

1 Like