# Kanban model in a console

A console program that uses `TAtlasKanbanModel` without any window, to show that the Kanban data model is
independent of the board control. It:

1. builds a board of four columns, one of them with a work-in-progress limit of 2, and four cards, and counts
   the `OnChange` notifications;
2. shows that duplicate ids, a full column, a destination index out of range and an unknown card are all
   refused with `EAtlasKanban`, and that the board is unchanged afterwards;
3. moves cards with a `BeforeMove` rule (cards enter Done only from Review), shows a vetoed move returning
   `False`, reorders a card inside its column with an explicit index, and shows that the callback cannot change
   the board while a move is in progress;
4. saves the board with `ToJSON`, loads it into a second model, and shows that a wrong schema, text that is not
   JSON and a card without a `detail` field are refused without touching the existing board;
5. replaces a card to change its title (there is no rename), removes a card, and clears the board by loading an
   empty document.

Every step checks its own result. The program prints what it did and exits with code 0 when all checks pass,
or prints the failed check and exits with code 1. It needs no input, files or network.

## Build and run

Open `KanbanModelConsole.dpr` in Delphi 13; the IDE creates the project file. Add the Atlas UI `src` folder and the Atlas VCL `src` folder to the project's search path, then build and run for Win32 or Win64. No packages need to be installed. The program needs no input. It checks its own results and stops with an error if any of them differs from the output below.

Only `Atlas.Kanban` is used; the model itself needs no form, although the unit links the VCL because the board control lives in the same unit.

## Expected output

```
Building the board
  To do (2)
    order-42: Prepare customer order
    invoice-7: Send invoice 7
  In progress (2/2)
    audit: Stock audit
    catalog: Update the catalog
  Review (0)
  Done (0)
  ok: four columns, two cards waiting
  ok: OnChange fired once per column and card
Validation
  ok: duplicate column id refused
  ok: duplicate card id refused
  ok: work limit refuses a third card
  ok: work limit refuses a move into a full column
  ok: destination index out of range
  ok: unknown card refused
  ok: refused operations leave the board unchanged
Moving cards
  ok: audit goes to review
  ok: BeforeMove cannot mutate the board
  ok: the freed slot accepts order-42
  ok: veto: catalog cannot skip review
  ok: vetoed card stays where it was
  ok: audit may finish from review
  ok: explicit index reorders inside a column
  ok: order-42 is first in progress
  ok: a move to the same place succeeds
  ok: only real moves fire OnChange
  To do (1)
    invoice-7: Send invoice 7
  In progress (2/2)
    order-42: Prepare customer order
    catalog: Update the catalog
  Review (0)
  Done (1)
    audit: Stock audit
JSON round trip
  {"schema":1,"columns":[{"id":"todo","title":"To do","limit":0,"cards":[{"id":"invoice-7","title":"Send invoice 7","detail":""}]},{"id":"active","title":"In progress","limit":2,"cards":[{"id":"order-42","title":"Prepare customer order","detail":"Pick, pack and label"},{"id":"catalog","title":"Update the catalog","detail":""}]},{"id":"review","title":"Review","limit":0,"cards":[]},{"id":"done","title":"Done","limit":0,"cards":[{"id":"audit","title":"Stock audit","detail":""}]}]}
  ok: a second model loads the same board
  ok: unknown schema refused
  ok: invalid text refused
  ok: a card without "detail" fails in the JSON reader
  ok: failed imports leave the board intact
Editing and clearing
  ok: the replacement goes back to the top
  ok: same id, new title and detail
  ok: removed card is gone
  ok: loading an empty document clears the board
All checks passed.
```

Six moves are attempted in "Moving cards" but only four fire `OnChange`: the vetoed move changes nothing, and
the last move puts `order-42` where it already is, which `MoveCard` reports as success without a notification.
A missing JSON field raises the RTL's `EJSONException` rather than `EAtlasKanban`, so code that loads boards
from files should catch both.

## Adapting it

- Replace `TRules.BeforeMove` with your own rule. It must only read the model: adding, removing or moving cards
  there raises `EAtlasKanban` (`Cannot mutate the board during a move callback`).
- Save `ToJSON` to a file or a database column and restore it with `LoadJSON`; the text is plain UTF-16 in
  memory, so choose the encoding when you write it (UTF-8 is a good default).
- To show the same model on screen, assign it to a `TAtlasKanban` board's `Model`; see the
  [Kanban board](https://youseful.software/delphi/projects/atlas-ui-kanbanboard.html) sample.