add settings model with option for overriding import/export config

[therealkevinard]

Provide a backend config option to allow end-users to inject custom $importExportConfig.

RainLab/User might be the most extended plugin on the market. This config allows a (fairly advanced) feature for overriding the default import/export config.

Example Usage:

• In my custom plugin, I add a folder at $/my/plugin/vojtasvoboda_userimportexport/
• add config_import_export.yaml

  
  import:
  title: Import Users
  modelClass: VojtaSvoboda\UserImportExport\Models\UserImportModel
  list: $/vojtasvoboda/userimportexport/models/userimport/columns.yaml # uses default config for import
  redirect: rainlab/user/users

export: title: Export Users modelClass: VojtaSvoboda\UserImportExport\Models\UserExportModel list: $/my/plugin/vojtasvoboda_userimportexport/userexport_columns.yaml # uses customized config for export redirect: rainlab/user/users

- add a custom `userexport_columns.yaml`

===================================

Column Definitions

===================================

columns:

id: label: Id invisible: true

username: label: rainlab.user::lang.user.username searchable: true invisible: true

name: label: rainlab.user::lang.user.name searchable: true

surname: label: rainlab.user::lang.user.surname searchable: true invisible: true

email: label: rainlab.user::lang.user.email searchable: true

// Custom fields added elsewhere address_1: label: Address address_2: label: Address 2 city: label: City state_region: label: State postcode: label: Zip Code country: label: Country membership_payment_source: label: Source member_status: label: Status

- In October backend/admin navigate to `/system/settings/update/vojtasvoboda/userimportexport/config` and add `$/my/plugin/vojtasvoboda_userimportexport/config_import_export.yaml` as the custom override. 

[vojtasvoboda]

Hello @therealkevinard, thank you for your contribution.

I think the correct way how to extend plugin is described here: https://octobercms.com/docs/plugin/extending

Try to use something like that:

Event::listen('backend.form.extendFields', function ($widget) {
    if (!$widget->getController() instanceof UserImportExport) {
        return;
    }

    if (!$widget->model instanceof UserExportModel) {
        return;
    }

    $controler = $widget->getController();
});

Also check my overriding example repository, where you can find handy addColumns and addFields method: https://github.com/vojtasvoboda/oc-brands-plugin-override-example

Good luck, Vojta.

[therealkevinard]

Okay, fair enough :) I didn't realize the traditional extend would work for this as well.

I take back my PR.