Connections

What this page covers

This page explains how to connect nodes in DiagramFlow. It covers direction, undirected links, edge attributes, chained expressions, and multi-line flow patterns.

Mental model

Connections describe relationships between nodes. In a cloud architecture diagram, that usually means traffic flow, data flow, event flow, or a logical dependency between services.

Start with the simplest possible edge, then add labels or styling only when they improve understanding.

Basic syntax

The simplest connection is a directed edge:


a = EKS("a")
b = SQS("b")

a -> b

Attributes and options

Directed right: `a -> b`

Use -> when the flow goes from left to right in the expression:


a = EKS("a")
b = SQS("b")

a -> b

Directed left: `a <- b`

Use <- when you want to express the relationship in the opposite direction:


a = EKS("a")
b = SQS("b")

a <- b

Undirected: `a - b`

Use - when you want to show a link without directional emphasis:


a = EKS("a")
b = SQS("b")

a - b

Edge attributes

Edge attributes are written inline after the operator.

Label only:


a = EKS("a")
b = SQS("b")

a ->[label="publish"] b

Color only:


a = EKS("a")
b = SQS("b")

a ->[color="firebrick"] b

Label, color, and style together:


a = EKS("a")
b = SQS("b")

a ->[label="dispatch", color="darkgreen", style="dashed"] b

Common style examples shown in the source examples include dashed, solid, dotted, and bold.

Common patterns

Chain simple flows

Chaining is concise for short sequences:


a = EKS("a")
b = SQS("b")
c = Lambda("c")

a -> b -> c

Split larger flows across lines

For diagrams that are more than a tiny example, multi-line flows are usually easier to read:


source = EKS("source")
queue = SQS("queue")
handler = Lambda("handler")
store = S3("store")

source -> queue
queue ->[label="consume", style="solid"] handler
handler -> store

This is often a better default than one very long chain.

Mixed operators

DiagramFlow also supports mixed connection operators in one expression:


a = EKS("a")
b = SQS("b")
c = Lambda("c")
d = S3("d")

a -> b - c <- d

Use this form carefully. It is compact, but harder to scan than separate lines.

Recommended usage

Start with plain -> edges and add attributes only when they communicate something useful.
Use labels for actions such as publish, consume, read, or write.
Use color and edge style sparingly so the important relationships stand out.
Prefer multi-line connections once a flow has more than two or three steps.
Treat mixed operators as advanced shorthand, not the default style for production diagrams.

Common mistakes

Encoding too much meaning into edge colors and styles before the basic flow is clear.
Using one long chained expression for a large diagram when separate lines would be easier to review.
Mixing ->, <-, and - in one expression without a strong readability reason.