core: customisable user settings (#2397)

* tenants: add user_settings flow, add basic flow and basic new executor

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/user: use flow PromptStage instead of custom stage

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/flows: add tenant to StageHost interface

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/user: fix form missing component

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/user: re-add success message

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/user: improve support for multiple error messages

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* stages/prompt: allow expressions in prompt placeholders

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* stages/prompt: add tests

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* flows: always set pending user

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* flows: never cache stage configuration flow plans

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* stages/user_write: fix error when pending user is anonymous user

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/admin: add checkbox for prompt placeholder expression

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* website/docs: add prompt expression docs

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* stages/prompt: add ak-locale field type

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* tenants: fix default policy

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/user: add function to do global refresh

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* web/flows: fix rendering of ak-locale

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* tenants: fix default policy, add error handling to placeholder, fix locale attribute

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

* add tests

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

website/docs/flow/stages/prompt/index.md

@@ -10,18 +10,31 @@ The prompt can be any of the following types:
 
 | Type     | Description                                                       |
 | -------- | ----------------------------------------------------------------- |
-| text     | Arbitrary text. No client-side validation is done.                |
-| email    | Email input. Requires a valid email address.                       |
-| password | Password input.                                                   |
-| number   | Number input. Any number is allowed.                              |
-| checkbox | Simple checkbox.                                                  |
-| hidden   | Hidden input field. Allows for the pre-setting of default values. |
+| Text | Arbitrary text. No client-side validation is done. |
+| Text (Read only) | Same as above, but cannot be edited. |
+| Username | Same as text, except the username is validated to be unique. |
+| Email | Text input, ensures the value is an email address (validation is only done client-side). |
+| Password | Same as text, shown as a password field client-side, and custom validation (see below). |
+| Number | Numerical textbox.  |
+| Checkbox | Simple checkbox.  |
+| Date | Same as text, except the client renders a date-picker |
+| Date-time | Same as text, except the client renders a date-time-picker |
+| Separator | Passive element to group surrounding elements |
+| Hidden | Hidden input field. Allows for the pre-setting of default values. |
+| Static | Display arbitrary value as is |
+| authentik: Locale | Display a list of all locales authentik supports. |
+
+Some types have special behaviors:
+
+ - *Username*: Input is validated against other usernames to ensure a unique value is provided.
+ - *Password*: All prompts with the type password within the same stage are compared and must be equal. If they are not equal, an error is shown
+ - *Hidden* and *Static*: Their placeholder values are defaults and are not user-changeable.
 
 A prompt has the following attributes:
 
 ### `field_key`
 
-The HTML name used for the prompt. This key is also used to later retrieve the data in expression policies:
+The field name used for the prompt. This key is also used to later retrieve the data in expression policies:
 
 ```python
 request.context.get('prompt_data').get('<field_key>')
@@ -39,6 +52,11 @@ A flag which decides whether or not this field is required.
 
 A field placeholder, shown within the input field. This field is also used by the `hidden` type as the actual value.
 
+By default, the placeholder is interpreted as-is. If you enable *Interpret placeholder as expression*, the placeholder
+will be evaluated as a python expression. This happens in the same environment as [_Property mappings_](../../../property-mappings/expression).
+
+You can access both the HTTP request and the user as with a mapping. Additionally, you can access `prompt_context`, which is a dictionary of the current state of the prompt stage's data.
+
 ### `order`
 
 The numerical index of the prompt. This applies to all stages which this prompt is a part of.