Chart Graphviz Lookup

Where the charts find Graphviz

The charts draw their pictures with Graphviz dot.exe; this page says where the engine looks for it and how to point it somewhere else. The text answers of drag-lint ask and the Reports menu never need Graphviz: when no dot.exe is found the text is still delivered, with NOTE the chart could not be drawn.

The order

The engine takes the first candidate that exists:

step	where	how to set it
1	DRAGLINT_DOT	environment variable naming dot.exe
2	%APPDATA%\drag-lint\settings.json, key dot	{ "dot": "C:\\Graphviz\\bin\\dot.exe" }
3	graphviz\bin\dot.exe in the charts files folder	an installed copy
4	graphviz\bin\dot.exe one folder above it	the Setup installer layout
5	graphviz\bin\dot.exe in the folder above charts\	an earlier installed layout
6	dot.exe on PATH	a Graphviz you installed yourself
7	C:\Projects\GraphWiz\Graphviz-16.1.0-win64\bin\dot.exe	the shared default of a development machine

A missing or unreadable settings.json, a missing key or an unset variable is skipped. A path someone SET -- DRAGLINT_DOT or the settings.json key -- that does not exist is an error naming where it was set, so a typo never silently picks another file. When nothing exists the error names every place looked at, in order. PATH is walked entry by entry; the current folder is never searched.

Examples

$env:DRAGLINT_DOT = 'C:\Graphviz\bin\dot.exe'     (this session only)

or, for good, in %APPDATA%\drag-lint\settings.json:

{ "dot": "C:\\Graphviz\\bin\\dot.exe" }

See also

Charts and the IDE, Diagrams and Charts, ask. Code: src\charts\DRagLint.Charts.Tools.pas (ResolveGraphvizDot).