drawio-impl-csv-import

Draw.io CSV Import Implementation

Purpose

This skill enables correct generation of Draw.io diagrams from CSV (tabular) data. It covers the complete CSV import format: directive lines that configure shape rendering, connection routing, conditional styling, and automatic layout. The CSV import feature converts rows into shapes and column references into connections, labels, and styles.

Critical Rules (Memorize These)

ALWAYS place ALL directive lines BEFORE the CSV header row — Directives start with #. Data rows NEVER start with #.
ALWAYS include a # label: directive — Without it, shapes render with no visible text.
ALWAYS use valid JSON in # connect: directives — The value MUST be a JSON object with "from" and "to" keys as strings. NEVER use bare words or single quotes.
ALWAYS wrap column references in % delimiters — Use %columnName% in labels, styles, and connect directives. NEVER use {columnName} or $columnName.
ALWAYS include a CSV header row — The first non-directive, non-comment line MUST contain column names that match all %placeholder% references.
NEVER put data values in directive lines — Directives define templates; data comes from CSV rows only.
ALWAYS use # identity: when connection targets reference a column other than the first — Without it, Draw.io matches against the first column by default.
ALWAYS use # ignore: for utility columns — Columns used only for styling, connections, or IDs MUST be listed in ignore to prevent them from appearing as shape metadata.

CSV Format Structure

The CSV import format consists of three sections in strict order:

1. Comment lines        (## prefix — ignored by parser)
2. Directive lines      (# prefix — configure rendering)
3. CSV header row       (column names, comma-separated)
4. CSV data rows        (values, comma-separated — one shape per row)

Directive Reference

Label Directive

Defines the text displayed inside each shape. Supports HTML and column placeholders.

# label: %name%
# label: %name%<br><i style="color:gray;">%role%</i>
# label: <b>%title%</b><br>%description%

Style Directive

Sets the mxGraph style string applied to ALL shapes. Supports column placeholders for dynamic values.

# style: rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;
# style: shape=ellipse;whiteSpace=wrap;html=1;fillColor=%fill%;strokeColor=%stroke%;

Conditional Style Directives

Use stylename + styles together to apply different styles based on a column value.

# stylename: type
# styles: {"server": "shape=image;image=server.png;", \
#   "database": "shape=cylinder3;whiteSpace=wrap;html=1;", \
#   "client": "rounded=1;whiteSpace=wrap;html=1;"}

Rules:

stylename names the column whose values act as style keys.
styles is a JSON object mapping column values to mxGraph style strings.
Every distinct value in the stylename column MUST have a corresponding key in styles.
NEVER mix style and stylename/styles — use one approach or the other.

Identity Directive

Designates which column provides unique identifiers for connection matching.

# identity: id

If omitted, the first column is used as the identity.
Connection targets ("to") match against the identity column values.

Namespace Directive

Adds a prefix to all generated cell IDs to prevent collisions when importing multiple CSVs.

# namespace: orgchart-

Connect Directive

Defines connections (edges) between shapes. MUST be valid JSON.

# connect: {"from": "manager", "to": "name", "invert": true, "label": "reports to", \
#   "style": "curved=1;endArrow=blockThin;endFill=1;fontSize=11;"}

JSON properties:

Property	Type	Required	Description
`from`	string	YES	Column name in the current row containing the target reference
`to`	string	YES	Column name in the target row to match against (matched via identity)
`invert`	boolean	NO	If `true`, reverses arrow direction (arrow points from target to source)
`label`	string	NO	Text label displayed on the edge
`style`	string	NO	mxGraph style string for the edge

Multiple connections require separate # connect: lines:

# connect: {"from": "manager", "to": "name", "invert": true}
# connect: {"from": "refs", "to": "id", "style": "dashed=1;"}

Layout Directive

Specifies the automatic layout algorithm applied after import.

# layout: auto
# layout: verticalTree
# layout: horizontalTree
# layout: organic
# layout: circle

Layout	Best For
`auto`	General purpose (Draw.io picks the best algorithm)
`verticalTree`	Org charts, hierarchies (top-to-bottom)
`horizontalTree`	Left-to-right hierarchies
`organic`	Network topologies, unstructured graphs
`circle`	Peer relationships, ring topologies

Dimension Directives

Control shape sizing:

# width: auto
# width: 120
# height: auto
# height: 60

auto sizes shapes to fit their label content.
Numeric values set fixed pixel dimensions for ALL shapes.

Spacing Directives

Control distance between elements in the auto-layout:

# padding: -12
# nodespacing: 40
# levelspacing: 100
# edgespacing: 40

Directive	Purpose	Default
`padding`	Internal label padding (negative reduces it)	0
`nodespacing`	Horizontal distance between sibling nodes	40
`levelspacing`	Vertical distance between hierarchy levels	100
`edgespacing`	Distance between parallel edges	40

Ignore Directive

Lists columns to exclude from shape metadata/tooltips. Utility columns (IDs, color codes, connection targets) MUST be ignored.

# ignore: id,fill,stroke,manager,refs,image

Link Directive

Designates a column whose values become hyperlinks on the shapes.

# link: url

Parent Style Directive

Sets the style for automatically created parent/container shapes (used when the layout groups nodes).

# parentstyle: swimlane;whiteSpace=wrap;html=1;childLayout=stackLayout;horizontal=1;horizontalStack=0;resizeParent=1;resizeLast=0;collapsible=1;

Line Continuation

Long directive lines can be split using backslash \ at the end of a line. The next line MUST start with #:

# connect: {"from": "manager", "to": "name", "invert": true, \
#   "label": "manages", "style": "curved=1;endArrow=blockThin;endFill=1;"}

Column Reference Syntax

Wrap column names in % delimiters to insert row values:

%columnName%

Column references work in:

# label: — inserts values into shape labels
# style: — inserts values into style strings (e.g., fillColor=%fill%)
# connect: — column names in from/to reference column headers

Import Method

Menu path: Arrange > Insert > Advanced > CSV

A dialog accepts the combined directive + CSV text. Import generates the diagram on the canvas immediately.

Complete Example: Org Chart

## Organizational chart with hierarchy
# label: %name%<br><i style="color:gray;">%position%</i>
# style: label;whiteSpace=wrap;html=1;rounded=1;fillColor=%fill%;strokeColor=%stroke%;
# namespace: org-
# identity: name
# connect: {"from": "manager", "to": "name", "invert": true, \
#   "style": "curved=1;endArrow=blockThin;endFill=1;fontSize=11;"}
# width: auto
# height: auto
# padding: -12
# ignore: fill,stroke,manager
# layout: verticalTree
# nodespacing: 40
# levelspacing: 100
#
name,position,manager,fill,stroke
Alice Johnson,CEO,,#dae8fc,#6c8ebf
Bob Smith,CTO,Alice Johnson,#d5e8d4,#82b366
Carol White,CFO,Alice Johnson,#d5e8d4,#82b366
Dave Brown,Lead Dev,Bob Smith,#fff2cc,#d6b656
Eve Davis,DevOps,Bob Smith,#fff2cc,#d6b656
Frank Lee,Accountant,Carol White,#fff2cc,#d6b656

Complete Example: Flowchart with Conditional Styles

## Process flow with different shape types
# label: %name%
# stylename: type
# styles: {"decision": "rhombus;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;", \
#   "process": "rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;", \
#   "terminal": "ellipse;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor=#b85450;"}
# connect: {"from": "next", "to": "id", "style": "endArrow=classic;html=1;"}
# identity: id
# namespace: flow-
# width: 120
# height: 60
# layout: auto
# ignore: id,next,type
#
id,name,type,next
start,Start,terminal,step1
step1,Process Data,process,check
check,Valid?,decision,step2
step2,Save Result,process,end
end,End,terminal,

Complete Example: Network Topology

## Network diagram with device types
# label: %hostname%<br><small>%ip%</small>
# stylename: device
# styles: {"router": "shape=mxgraph.cisco.routers.router;whiteSpace=wrap;html=1;", \
#   "switch": "shape=mxgraph.cisco.switches.workgroup_switch;whiteSpace=wrap;html=1;", \
#   "server": "shape=mxgraph.cisco.servers.standard_server;whiteSpace=wrap;html=1;", \
#   "firewall": "shape=mxgraph.cisco.firewalls.firewall;whiteSpace=wrap;html=1;"}
# connect: {"from": "uplink", "to": "hostname", "style": "endArrow=none;strokeWidth=2;"}
# identity: hostname
# namespace: net-
# width: 80
# height: 80
# layout: organic
# ignore: ip,device,uplink
#
hostname,ip,device,uplink
core-rtr,10.0.0.1,router,
fw-01,10.0.0.2,firewall,core-rtr
sw-floor1,10.0.1.1,switch,fw-01
sw-floor2,10.0.2.1,switch,fw-01
srv-web,10.0.1.10,server,sw-floor1
srv-db,10.0.1.11,server,sw-floor1
srv-mail,10.0.2.10,server,sw-floor2

Checklist: Before Outputting CSV Import Data

ALL directive lines appear before the CSV header row.
A # label: directive exists and references valid column names.
ALL # connect: values are valid JSON with double-quoted keys.
ALL %placeholder% names exactly match CSV column headers (case-sensitive).
A CSV header row exists as the first non-directive line.
Every data row has the same number of fields as the header.
Utility columns are listed in # ignore:.
# identity: is set if connections target a column other than the first.
# namespace: is set when multiple CSV imports coexist in one diagram.
# layout: is set to an appropriate algorithm for the data structure.

Cross-References

XML fundamentals: See drawio-core-xml-format for mxGraph file structure.
Style syntax: See drawio-syntax-styles for the complete style property reference.
Connection details: See drawio-syntax-connections for edge routing and style options.
Flowcharts: See drawio-impl-flowcharts for flowchart-specific shapes and patterns.

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