# Memory grid export

The quick start for Atlas Virtual Grid, and the project behind the
[tutorial](https://youseful.software/delphi/atlas-virtual-grid.html#tutorial). A console program that
never shows a window:

- fills a `TAtlasMemoryData` with six typed columns (number, text, date, yes/no)
  from invariant text, and shows that a row with a bad value is refused whole;
- binds a `TAtlasVirtualGrid`, which creates one column per data column, then
  sets format masks, bands and count/sum/average totals;
- sorts ascending and descending, filters on the formatted text, and checks
  that totals follow the filter;
- edits through the data source and shows the grid following it, including
  refused values and a read-only column;
- copies the selection as tab-separated text;
- writes `orders.csv`, `orders.html`, `orders.svg` and `orders.png`.

Every step checks its own result and raises on a mismatch, so the exit code is
0 only when everything matched.

## Build and run

Open `MemoryGridExport.dpr` in Delphi 13; the IDE creates the project file. Add the Atlas Virtual Grid `src` folder and the Atlas Plot `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.

## Expected output

```
1. Columns and rows
  ok: 6 rows, 6 columns
  ok: a row with a value that does not fit its column is rejected whole
2. Bind the grid and describe the columns
  ok: columns were created from the source
  ok: cells are formatted per column
  ok: totals: count 6, quantity sum 27, average price 229.21
3. Sort
  ok: ascending by customer; equal keys keep source order
  ok: descending by quantity; the null quantity comes last
4. Filter
  ok: 2 Fabrikam rows, still sorted
  ok: totals follow the filter
  ok: the filter reads the formatted date text: 3 rows shipped before 10 January
  ok: filter and sort removed
5. Edit through the data source
  ok: the grid follows the source: sum is now 32
  ok: text that is not a number is refused and the value kept
  ok: the read-only key column refuses writes
6. Selection text
  ok: tab-separated formatted rows, ready for the clipboard
7. Text output
Order,Customer,Shipped,Quantity,Unit price,Paid
1001,Contoso,2026-01-05,4,125.5,true
1002,Fabrikam,2026-01-06,12,40,false
1003,Northwind,2026-01-09,1,980,true
1004,Contoso,2026-01-12,5,125.5,false
1005,"Tailspin, Ltd",2026-01-15,7,64.25,true
1006,Fabrikam,,3,40,true

  ok: CSV carries raw values: invariant numbers, ISO dates, true/false
  ok: commas are quoted; nulls are empty
  ok: hidden columns are left out
  ok: HTML has the caption, bands and totals
8. Pictures and files
  ok: SVG of the visible part of the grid
  ok: orders.csv written to ...\MemoryGridExport
  ok: orders.html written to ...
  ok: orders.svg written to ...
  ok: orders.png written to ...
  ok: unknown extensions are refused
MemoryGridExport: all checks passed
```

`orders.png` shows two band headings (Shipment, Amount), right-aligned
numbers and dates, check boxes for the Paid column and a footer with 6, 32 and
229.21.

## Adapting it

- Replace the `AddRow` calls with your own data. Values are read with invariant
  settings (`'.'` decimals, ISO dates, `yes`/`no`); use `SetCell` with
  `TAtlasCell.OfNumber` and friends when you already have typed values.
- The program sets `FormatSettings := TFormatSettings.Invariant` so that its
  checks hold on every machine. In a real application leave the user's
  settings alone: the grid's formatted text (`CellText`, HTML, pictures)
  follows them, while CSV stays invariant.
- The pictures draw what would be on screen, starting at `TopRow`. For every
  row, use CSV or HTML.