Help:Diagrams - Revision history

Hash: Document the one-BPMN-or-Gantt-per-page limit instead of triggering it

2026-09-09T01:52:05Z

Document the one-BPMN-or-Gantt-per-page limit instead of triggering it

← Older revision		Revision as of 01:52, 9 September 2026
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	That renders the diagram inline wherever you put it, so an article can show a diagram that is maintained on its own page. Each section below gives the exact line for that format's example.		That renders the diagram inline wherever you put it, so an article can show a diagram that is maintained on its own page. Each section below gives the exact line for that format's example.

			'''One limit to know about:''' a single page can contain '''at most one BPMN or Gantt''' diagram — the extension gives both of them the same internal element name, so a second one on the same page is refused with an error message. Mermaid, DOT and Drawio can be embedded as many times as you like.

	== Mermaid ==		== Mermaid ==
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	{{#display_diagram:BPMN:Example diagram}}		{{#display_diagram:BPMN:Example diagram}}

			That embed uses this page's one BPMN-or-Gantt slot; a second diagram of either type on the same page would be refused.

	[[File:FlexDiagrams BPMN editor.png\|thumb\|none\|700px\|The BPMN editor: the shape palette down the left, canvas in the middle, zoom controls on the right.]]		[[File:FlexDiagrams BPMN editor.png\|thumb\|none\|700px\|The BPMN editor: the shape palette down the left, canvas in the middle, zoom controls on the right.]]
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	</pre>		</pre>

	~~which renders as~~:		This help page cannot show that live: it already embeds a BPMN diagram above, and only one BPMN-or-Gantt diagram is allowed per page (see [[#Showing a diagram on another page\|above]]). To see it rendered, open [[Gantt:Example diagram]] itself.

	{{#~~display_diagram:~~Gantt:Example diagram}}

	[[File:FlexDiagrams Gantt editor.png\|thumb\|none\|700px\|The Gantt editor: task grid on the left, timeline on the right, with zoom controls for hours through years.]]		[[File:FlexDiagrams Gantt editor.png\|thumb\|none\|700px\|The Gantt editor: task grid on the left, timeline on the right, with zoom controls for hours through years.]]

Hash: Restructure: a section per format with an editable example, embed syntax and an editor screenshot slot

2026-09-09T01:50:59Z

Restructure: a section per format with an editable example, embed syntax and an editor screenshot slot

Show changes

Hash: Fix wrapped list items rendering as preformatted blocks

2026-09-09T00:21:43Z

Fix wrapped list items rendering as preformatted blocks

← Older revision		Revision as of 00:21, 9 September 2026
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	== Tips ==		== Tips ==

	* Diagrams are ordinary pages: <code>History</code>, <code>Talk</code>, watchlisting and		* Diagrams are ordinary pages: <code>History</code>, <code>Talk</code>, watchlisting and the normal backups all apply.
	the normal backups all apply.		* Because Mermaid and DOT are text, their page histories produce readable diffs — prefer them over an uploaded image when the diagram is likely to change.
	* Because Mermaid and DOT are text, their page histories produce readable diffs — prefer		* In a '''BPMN''' diagram, an element named <code><nowiki>[[Some page]]</nowiki></code> becomes a link to that wiki page.
	them over an uploaded image when the diagram is likely to change.		* Give diagrams descriptive names, the same as files — <code>Mermaid:Landis Gyr Focus teardown steps</code> beats <code>Mermaid:Diagram 3</code>.
	* In a '''BPMN''' diagram, an element named <code><nowiki>[[Some page]]</nowiki></code>
	becomes a link to that wiki page.
	* Give diagrams descriptive names, the same as files —
	<code>Mermaid:Landis Gyr Focus teardown steps</code> beats
	<code>Mermaid:Diagram 3</code>.

	== See also ==		== See also ==

	* [[Help:Uploading files]] — for photographs, scans and CAD files		* [[Help:Uploading files]] — for photographs, scans and CAD files
	* [https://www.mediawiki.org/wiki/Extension:Flex_Diagrams Extension:Flex Diagrams] — the		* [https://www.mediawiki.org/wiki/Extension:Flex_Diagrams Extension:Flex Diagrams] — the extension providing this
	extension providing this

Hash: How to create and embed diagrams (Flex Diagrams)

2026-09-09T00:13:10Z

How to create and embed diagrams (Flex Diagrams)

New page

This wiki can store '''diagrams as diagrams''' rather than as uploaded pictures. A
diagram lives on its own page, keeps a full edit history like any other page, and can be
re-opened and changed by the next person — no hunting for the original file, and no
re-uploading a flat image every time something moves.

You need to be logged in and in the '''writer''' group to create or change a diagram.
Anyone can view them.

== The five formats ==

Each format has its own namespace, and each has its own editor.

{| class="wikitable"
! Namespace !! Best for !! How you edit it
|-
| '''Mermaid:''' || Flowcharts, sequence diagrams, state machines, ER diagrams, timelines || Text — you write a few lines of Mermaid syntax
|-
| '''DOT:''' || Graphs and trees: signal chains, network maps, workflows || Text — Graphviz DOT syntax
|-
| '''Drawio:''' || Free-form drawings, block diagrams, anything you want to drag around || Full visual editor (draw.io / diagrams.net)
|-
| '''BPMN:''' || Formal business-process diagrams || Visual editor
|-
| '''Gantt:''' || Project schedules with dependencies || Visual editor
|}

'''Mermaid''' and '''DOT''' are the two most useful here for typical hardware, RF and
reverse-engineering documentation, and they are the easiest to review in a diff because
the source is plain text.

== Creating a diagram ==

The easiest way is to '''write a red link and click it''':

# On any page, add a link in a diagram namespace, for example <code><nowiki>[[Mermaid:Meter capture chain]]</nowiki></code>.
# Save, then click the new red link.
# The diagram editor opens directly. Fill it in and save.

You can also go straight to the editor for a page that does not exist yet by visiting
its URL with <code>?action=editdiagram</code> on the end.

On a diagram page that already exists, use the '''Edit diagram''' tab at the top.

== Showing a diagram on another page ==

Diagram pages are not transcluded with the usual double braces. Use the
<code>#display_diagram</code> parser function instead:

<pre>
{{#display_diagram:Mermaid:Meter capture chain}}
</pre>

That renders the diagram inline wherever you put it, so an article can show a diagram
that is maintained on its own page.

== Mermaid example ==

The source of [[Mermaid:Example diagram]] is simply:

<pre>
flowchart LR
A[Smart meter] -->|900 MHz| B(SDR capture)
B --> C{Decodes?}
C -->|yes| D[rtlamr output]
C -->|no| E[Adjust gain / freq]
E --> B
</pre>

which renders as:

{{#display_diagram:Mermaid:Example diagram}}

Mermaid supports far more than flowcharts — sequence diagrams, state diagrams, class
diagrams, ER diagrams, pie charts, timelines and Gantt charts are all available. See
[https://mermaid.js.org/intro/ the Mermaid documentation] for the full syntax. Note that
this wiki bundles '''Mermaid 10.9''', so diagram types added in Mermaid 11 will not
render.

== DOT example ==

[[DOT:Example diagram]] contains:

<pre>
digraph FlashExtraction {
rankdir=LR;
node [shape=box];
"Target PCB" -> "Desolder chip";
"Desolder chip" -> "Socket adapter";
"Socket adapter" -> "Programmer";
"Programmer" -> "Binary dump";
"Binary dump" -> "Analysis";
}
</pre>

giving:

{{#display_diagram:DOT:Example diagram}}

DOT is good when you want the layout worked out for you — you describe what connects to
what, and Graphviz arranges it.

== A note on Drawio ==

The '''Drawio:''' editor is the full diagrams.net drawing tool, loaded from the external
site <code>embed.diagrams.net</code> while you are editing. Your diagram is saved here on
the wiki, not on their servers, and viewing a saved Drawio diagram does not contact them
at all — but ''editing'' one does need that external site to be reachable from your
browser. The other four formats are served entirely from this wiki.

== Tips ==

* Diagrams are ordinary pages: <code>History</code>, <code>Talk</code>, watchlisting and
the normal backups all apply.
* Because Mermaid and DOT are text, their page histories produce readable diffs — prefer
them over an uploaded image when the diagram is likely to change.
* In a '''BPMN''' diagram, an element named <code><nowiki>[[Some page]]</nowiki></code>
becomes a link to that wiki page.
* Give diagrams descriptive names, the same as files —
<code>Mermaid:Landis Gyr Focus teardown steps</code> beats
<code>Mermaid:Diagram 3</code>.

== See also ==

* [[Help:Uploading files]] — for photographs, scans and CAD files
* [https://www.mediawiki.org/wiki/Extension:Flex_Diagrams Extension:Flex Diagrams] — the
extension providing this