* FEATURE: Exposing a way to add a generic report filter
## Why do we need this change?
Part of the work discussed [here](https://meta.discourse.org/t/gain-understanding-of-file-uploads-usage/104994), and implemented a first spike [here](https://github.com/discourse/discourse/pull/6809), I am trying to expose a single generic filter selector per report.
## How does this work?
We basically expose a simple, single generic filter that is computed and displayed based on backend values passed into the report.
This would be a simple contract between the frontend and the backend.
**Backend changes:** we simply need to return a list of dropdown / select options, and enable the report's newly introduced `custom_filtering` property.
For example, for our [Top Uploads](https://github.com/discourse/discourse/pull/6809/files#diff-3f97cbb8726f3310e0b0c386dbe89e22R1423) report, it can look like this on the backend:
```ruby
report.custom_filtering = true
report.custom_filter_options = [{ id: "any", name: "Any" }, { id: "jpg", name: "JPEG" } ]
```
In our javascript report HTTP call, it will look like:
```js
{
"custom_filtering": true,
"custom_filter_options": [
{
"id": "any",
"name": "Any"
},
{
"id": "jpg",
"name": "JPG"
}
]
}
```
**Frontend changes:** We introduced a generic `filter` param and a `combo-box` which hooks up into the existing framework for fetching a report.
This works alright, with the limitation of being a single custom filter per report. If we wanted to add, for an instance a `filesize filter`, this will not work for us. _I went through with this approach because it is hard to predict and build abstractions for requirements or problems we don't have yet, or might not have._
## How does it look like?
## More on the bigger picture
The major concern here I have is the solution I introduced might serve the `think small` version of the reporting work, but I don't think it serves the `think big`, I will try to shed some light into why.
Within the current design, It is hard to maintain QueryParams for dynamically generated params (based on the idea of introducing more than one custom filter per report).
To allow ourselves to have more than one generic filter, we will need to:
a. Use the Route's model to retrieve the report's payload (we are now dependent on changes of the QueryParams via computed properties)
b. After retrieving the payload, we can use the `setupController` to define our dynamic QueryParams based on the custom filters definitions we received from the backend
c. Load a custom filter specific Ember component based on the definitions we received from the backend
A first load was happening in route, which was setting properties on controller. These properties were observed on the controller and were triggering a reload of the AdminUser model.
Not only was it doing loading two times it was also sometimes resulting on the controller model refresh end to happen after route has been changed, resulting in a wrong model.
Removing the theme_field JS object when the value was empty caused the server to maintain the previous value, making it impossible to delete the content of a field.
- These advanced fields are hidden behind an 'advanced' button, so will not affect normal use
- The editor has been refactored into a component, and styling cleaned up so menu items do not overlap on small screens
- Styling has been added to indicate which fields are in use for a theme
- Icons have been added to identify which fields have errors
