Environment

Blocks#

Besides code, a wmn document can hold a small set of rich blocks. Each is a fenced block whose language starts with wmn:, so it stays readable as text in any Markdown viewer. The body is usually key: value lines, one per line.

Code#

A fenced block with a language and optional attributes, as described in The document format. On a runnable page a block the machine can run gets a Run button; the first Run on a page starts the machine, and later Runs reuse it.

Input#

A control whose value the blocks that use it can read.

markdown

```wmn:input {#count}
name: count
type: slider
min: 0
max: 100
value: 42
```

Not runnable: this document names no image (`image:` in its front matter), so there is nothing to run its code on.

type is one of text, number, slider, select, date or file. Other keys are label, step, options and accept. A code block reads the value with uses=count, as the variable count.

Chart#

A chart of a table that a code block produced.

markdown

```wmn:chart {#sales-chart}
source: sales
type: bar
x: month
y: total
title: Sales by month
```

Not runnable: this document names no image (`image:` in its front matter), so there is nothing to run its code on.

source is the id of the block whose output is a table.

Callout#

A note that stands out. The body is Markdown and kind= is note, tip, important, warning or caution.

markdown

```wmn:callout {kind=warning}
This **overwrites** the table.
```

Not runnable: this document names no image (`image:` in its front matter), so there is nothing to run its code on.

Tabs#

Show one of several blocks at a time. Each entry names a block by id; the blocks follow the tabs block in the document.

markdown

```wmn:tabs
- { label: SQL, block: create-table }
- { label: Python, block: load }
```

Not runnable: this document names no image (`image:` in its front matter), so there is nothing to run its code on.

Embed#

A web page inside the document, with src= and height= attributes. Some tools show it as plain code rather than drawing the page.

Library blocks#

A wmn:use block draws with a view from a block package. The front matter pins the package, and the block names it and the block to use:

markdown

---
blocks:
  charts:
    from: stdlib/charts
    version: "1.0.0"
    sha256: <the package hash>
---

```wmn:use {#trend lib=charts block=line-chart}
source: temperature
x: hour
y: temperature
```

Not runnable: this document names no image (`image:` in its front matter), so there is nothing to run its code on.

lib= is the name pinned under blocks:, and block= is a block of that package.
source: names the block (or blocks, comma separated) that prints the table the view draws. uses= can name more.
The other lines are the view's parameters. A view cannot change source or the pin.
A package and its views are plain files. The view runs in a sandboxed frame that cannot read the page, use storage, or reach the network. It is sent only its parameters, the theme and the tables it was fed from.

Feeding a view#

The block named by source: prints a table, which a Python block can do with:

markdown

```python {#temperature}
display({"application/vnd.wmn.table+json": {"columns": ["hour", "temperature"], "rows": [[0, 18.0], [2, 17.4]]}}, raw=True)
```

Not runnable: this document names no image (`image:` in its front matter), so there is nothing to run its code on.

The page draws the view from the table saved with the page. After you press Run the view redraws from the table the machine printed.

The bundled packages#

Package	Blocks
`stdlib/charts`	Line chart (`line-chart`), Bar chart (`bar-chart`), Scatter plot (`scatter-plot`), Histogram and CDF (`histogram`). Parameters include `x`, `y`, `title` (and `column`, `bins` for the histogram).
`stdlib/explore`	Metric table (`metric-table`: totals for each column, with the changes between runs highlighted), Network graph (`network-graph`: a table of pairs drawn as nodes and edges), and the scrubbable number.
`stdlib/data`	Templates for loading a file and for an SQL query.
`stdlib/core`	The input, chart, callout, tabs, embed and code blocks above.

Scrubbers#

A number inside a sentence that you can drag. See The document format. Moving a scrubber re-runs the blocks that name it in uses=, and a live view fed from them redraws.