If you haven't done so, please read the Overview first.
This chapter describes the syntax of the text format that is parsed by
Graph::Easy::Parser
into a Graph::Easy object.
General rules
Comments
Comments start with a #
character and run til the end of the line.
Certain things are except from this rule, like color values like
#ff00aa
inside attributes, where the '#' will not start a comment.
To make sure that you comments are parsed correctly, always put a space as the first character after the hatch (entire lines consisting only of the '#' character are ok, though):
############################ # This is a good comment. ############################# #This is bad.
Whitespace
Whitespace does generally not matter, e.g. multiple spaces are collapsed together to one, and linebreaks are ignored. Whitespace at the front and end of label texts is removed, likewise. Thus the following two are equivalent:
[A]->[B][C]->[D]
[ A ] -> [ B ] [ C ] -> [ D ]
When writing graph text, you are encouraged to use whitespace and linebreaks for clarity, like in the second example above.
To insert a line break into a node or edge label, use literally \n
:
[ My\n long\n node\n name ] -- A\n long\n label --> [ B ]
+------+ +---+ | My | A | | | long | long | B | | node | label | | | name | -------> | | +------+ +---+
Nodes
Nodes are written (or "quoted", if you wish) with enclosing square brackets:
[ Single node ] [ Node A ] --> [ Node B ]
You can also have a list of nodes by seperating them with a comma:
[ A ], [ B ], [ C ] --> [ D ]
+---+ +---+ +---+ | A | --> | D | <-- | C | +---+ +---+ +---+ ^ | | +---+ | B | +---+
It also works for lists on the right side of an edge:
[ A ] -> [ B ], [ C ], [ D ]
+---+ +---+ +---+ | B | <-- | A | --> | C | +---+ +---+ +---+ | | v +---+ | D | +---+
In addition, you can chain nodes together like this:
[ A ] -> [ B ] -> [ C ] -> [ D ] -> [ E ]
You can also create invisible, anonymous nodes with [ ]
. These nodes
are called anonymous, because you do not know their name and thus cannot refer
to them again:
[ ] -> [ Karlsruhe ] -> [ ] -> [ Plauen ]
That would be rendered like:
+-----------+ +--------+ --> | Karlsruhe | --> --> | Plauen | +-----------+ +--------+
If you merely want an invisible node, use shape: invisible;
:
[ $sys$Node ] { shape: invisible; title: You don't see me! } -> [ Bischofswerda ] -> [ $sys$Node ]
+---------------------+ v | +---------------+ | Bischofswerda | --> +---------------+
Attributes
Attributes are enclosed in { }
,
are in the format attributename: attributevalue;
and follow immidiately the object for that they apply.
Attributes on a node in a node list apply to all nodes in
the list that came to this point.
graph { background: white; } # for the graph itself node { background: white; } # for all nodes edge { style: bold; } # for all edges node.city { background: red; } # for all nodes with class "city" [ Bonn ] { class: city; } # for the node "Bonn" [ Bonn ] --> { style: dotted; } # for the edge "Bonn" to "Berlin" [ Berlin ] { color: green; } # for the node "Berlin" [ ABC ] { border: bold; color: white; } [ DEF ] # DEF has not yet attributes { fill: #ff8060; # applies only to DEF } , [ GHI ] { # these apply to DEF and GHI! border: bold; color: white; } , [ JKL ] { shape: circle; # apply to DEF, GHI and JKL } [ ] { fill: brown; } # for the anonymous node only
As a special case for autosplit nodes, you can seperate attribute values with "|" (vertical bar) for each part of the auto-split node:
[ Bonn | Berlin | Frankfurt ] { fill: red|yellow|blue; }
In the example above, "Bonn" would be red, "Berlin" yellow and "Frankfurt" blue. Missing values will not set the attribute on the node as in the following example, where "Berlin" and "Ulm" will get the default background (white):
node { fill: white; } [ Bonn | Berlin | Hahn | Ulm ] { fill: red||blue; }
For a complete listing of possible attributes see the appropriate chapter.
Edges
The edges between the nodes can have the following styles:
-> solid => double .> dotted ~> wave - > dashed .-> dot-dash ..-> dot-dot-dash = > double-dash
In addition to these, the following styles exist: "bold", "bold-dash", "broad" and "wide". Unlike the normal edge styles, these can only be set via the (optional) edge attributes:
[ A ] --> { style: bold; } [ B ] --> { style: broad; } [ B ] --> { style: bold-dash; } [ C ]
You can repeat each of the style-patterns as much as you like:
---> ==> => ~~~~~> ..-..-..->
Note that in patterns longer than one character, the entire pattern must be repeated e.g. all characters of the pattern must be present. Thus:
..-..-..-> # valid dot-dot-dash ..-..-..> # invalid! .-.-.-> # valid dot-dash .-.-> # invalid!
In additon to the styles, the following two directions are possible:
-- edge without arrow heads --> arrow at target node (end point) <--> arrow on both the source and target node (end and start point)
Of course you can combine all directions with all styles. However, note that edges without arrows cannot use the shortcuts for styles:
--- # valid .-.- # valid .- # invalid! - # invalid! ~ # invalid!
Just remember to use at least two repetitions of the full pattern for arrow-less edges.
You can also give edges a label, either by inlining it into the style, or by setting it via the attributes:
[ AB ] --> { style: bold; label: foo; } [ ABC ]
-- foo --> ... baz ...> -- solid --> == double ==> .. dotted ..> ~~ wave ~~> - dashed - > = double-dash = > .- dot-dash .-> ..- dot-dot-dash ..->
Note that the two patterns on the left and right of the label must be the same, and that there is a mandatory space between the left pattern and the label, as well as the label and the right pattern.
You may use inline labels only with edges that have at least one arrow. Thus:
<-- label --> # valid -- label --> # valid -- label -- # invalid!
To use a label with an edge without arrow heads, use the attributes:
[ AB ] -- { label: edgelabel; } [ CD ]
For a complete listing of possible edge attributes see the appropriate chapter.
Advanced Layouts
Joints
Sometimes you want on edge join another, or have a pair of edges start
at a common point, and then split up. Or you even want two edges being
connected by a third edge. Graph::Easy
allows all these things
by a feature called shared ports.
For detailed information and examples please see the chapter about joints.
Classes
Each part of a graph is a (primary) class and you can assign it attributes:
graph { color: red; } edge { color: blue; } node { color: green; } group { color: brown; }
All objects in a graph automatically belong to their primary class,
e.g. nodes are in the class "node". Except graph
, all primary
classes can have subclasses:
edge { color: blue; } edge.train { color: darkblue; } node { color: green; } node.cities { color: darkgreen; } group { color: brown; } group.cities { color: darkbrown; }
Groups
You can group nodes together by using braces:
( German Cities [ Berlin ] -> [ Potsdam ] ) { background: lightbrown; }
Putting nodes into a group gives the layouter the hint that these nodes are related and should be laid out closely together.
Please see the section about grouping for further details and examples.
Relative placement (via auto-split)
You can cluster nodes together by placing them relatively to each other.
Perhaps the easiest way to achive the placement is to use the
auto-split feature:
- a
|
(vertical bar) in the node name will split the node into two parts, and place them next to each other, horizontally - likewise,
||
(two vertical bars) in the node name will split the node into two parts, but place the second part at the start of a new row - If a part between two
|
consists of exactly one space, an invisible cell will be generated, e.g. one without borders and background - If a part between two
|
consists of more than one space, an empty cell (e.g. with borders and background) will be generated - Trailing empty parts will be ignored, so
[ A|B| ]
equals[A|B]
. If you want an empty/invisible cell as last part, add anoter|
:[ A|B| |]
Please see the section in Hinting for examples and explanations.