bpmn-visualization is a TypeScript library for visualizing process execution data on BPMN diagrams. It is in early development stages and is subject to change prior to the 1.0.0 release.

1. Overview

1.1. Live Examples

To see bpmn-visualization in action, give a try to the examples live environment.
You will quickly have an overview of the bpmn-visualization capabilities.

1.2. Source Code

bpmn-visualization is an open source library.
You can find the source code on GitHub.

We will be more than happy to exchange ideas and more with you on the subject.
Because who knows, if you feel like contributing (feature, bug, doc, etc), you are very welcome to do so! 🙂

1.3. Usage

1.3.1. Bundles

bpmn-visualization can be directly used in HTML pages or integrated in Javascript and TypeScript applications. It is distributed as a npm package in various bundle formats.

1.3.2. API

The API documentation is provided directly in the package thanks to the TypeScript declaration files that can be used in IDE for code assist.

There is also an HTML version which is available in the API HTML documentation.

1.3.3. More technical details

For more technical details and how-to, go to the bpmn-visualization-examples repository.

1.4. Glossary

Here are a list of terms and concepts we are using in the bpmn-visualization documentation, issues, examples…​

Table 1. Glossary
Term or concept Description

BPMN rendering

The part of the rendering that concerns purely the BPMN model according to the specification

Customization

The library user changes the rendering / behavior using their own code by extending the library

Configuration

The library user changes the rendering / behavior using existing features

Custom behavior

Any behavior that causes changes in the BPMN rendering (adding popup, changing elements color or thickness…​)

Diagram navigation

Set of user interactions, that permits pan and zoom, to achieve desired visibility on diagram elements or diagram as a whole

Options

Configuration elements used at the library initialization and by the APIs at runtime

Library integration

Something about how an app can integrate the library

Process data

Execution data + derived data

Execution data

Data that is generated during the natural process instance flow: state, logs, …​

Derived data

Data that by any means derives from the execution data and/or other contextual data

1.5. BPMN Diagrams

BPMN diagrams are at the foundation of the bpmn-visualization capabilities.

Go to Supported BPMN Elements section to better now what is the current BPMN support.

1.5.1. BPMN rendering

The first goal of bpmn-visualization is to render BPMN diagrams but this is up to the integration (i.e. the application that uses it) to provide the BPMN diagram content.
For instance, it can be retrieved from a local file, by pulling a REST API, made available after a push from websockets or SSE, …​

Once the integration gets the BPMN diagram input source, it just has to pass it to bpmn-visualization which is then in charge of rendering the diagram.

1.5.1.1. Default BPMN Theme

By default, the rendering uses the following settings:

  • fill color: white

  • stroke color: black

  • font:

    • family: Arial, Helvetica, sans-serif

    • color: black

    • size: 11

The default colors are deliberately neutral. They make it easy to highlight process data with specific colors.

If the defaults don’t fit your needs, please read how to customize the BPMN Theme.

Default BPMN Theme

Default BPMN Theme

1.5.1.2. Customizing the BPMN Theme

It is possible to change the default theme by extending bpmn-visualization or by using CSS in the page displaying the diagram.

  • Extending gives the full control on the theme customization, including colors, size, icons, and more.

  • CSS is the fastest to implement but provides fewer features. For instance, you cannot change the icons or precisely control the size of the strokes.

The current extension mechanism is experimental and subject to change.

For more details, see the Custom BPMN Theme examples.

Custom BPMN Theme

Custom BPMN Theme

1.5.2. Diagram Navigation

In addition to BPMN rendering, bpmn-visualization provides several ways to explore and navigate through the BPMN diagrams. This is made available at load time or at runtime, through user interactions or API calls.

The navigation features are:

  • zoom: change the diagram scale to show details or have an overview of the diagram.

  • fit: reset/set the zoom level and eventually translate the diagram (for instance, center the diagram).

  • pan: drag the diagram and move/translate it, to hidden parts or change the position in the view.

Navigation is particularly useful for large diagrams. Fitting the view to the screen provides a good overview of a large diagram, but it can be hard to see details.
You can zoom to highlight specific parts, then pan to view different diagram portions.
After navigating around, you may want to reset the zoom level and go back to a full diagram overview.

1.6. Process data

bpmn-visualization gives you the opportunity to visualize the Process Data on top of the BPMN diagrams. The purpose of the library is to gain the visibility on what happens in your processes.

Process Data consists of two main data sets:

  • Execution Data - data that accompanies the process instance (case) through the execution flow. All the events occurring along this workflow, contractual data and every other bits of information related to this particular instance from start to the end.

  • Derived Data - data that derives from the execution data: predictions, analysis, statistics. The other data that can be associated with the process instance can also be a part of this set.

1.6.1. Process data examples

The example of Process Data for different tasks can be as follows.

user task:

  • time of the execution

  • percentage of the time spent in this task in the scope of whole time to finish the process instance

  • data related to list of activities done to complete this task:

    • SAP data manipulations

    • messaging system data

    • Microsoft Excel entries (reporting)

    • other proprietary systems data

service task:

  • time of the execution

  • data related to list of activities done to complete this task:

    • RPA robot data

    • external API call

    • …​

1.7. Custom behavior

bpmn-visualization provides API to interact with the BPMN elements and their representation as DOM Element.

Fore more examples about Custom Behavior, see the examples live environment

1.7.1. BPMN semantic and DOM Element

A BPMN element contains BPMN semantic information that can be matched with Process data. The DOM Element let you manipulate the representation and allow enriching its behavior by adding event listeners for instance.

The following example demonstrates how to let users interact with a BPMN diagram when clicking on a task, passing the mouse over another task or a transition between two elements.
Here, it displays BPMN information only, but it could use this feature to display execution data related to the current BPMN element: execution time and details, pending user of an activity, current error at this stage of the process, and more.

Display popovers on over or click

Display popovers on over or click

1.7.2. Style

The style of BPMN elements can be modified at runtime allowing to mark, hide, change appearance of one or several specific elements. For instance, this feature can be used to mark a task as in error, warn that an activity has been started for a while and seems stuck, …​

This example shows how to see which path in a process is the current running activity.

custom behavior path highlighting

Path highlighting with the miwg-test-suite C.1.1 BPMN diagram

1.8. Overlays

bpmn-visualization provides API to add overlays on top of BPMN elements. This additional overlays layer permits you to show whatever data you want and enrich your diagrams.

1.8.1. Use case

There are various use cases concerning overlays. For example the aforementioned Process data can be easily displayed in rectangular shapes on top of the edges and tasks. Whether you would like to show a path frequency or probability for the next step, the overlays are here to help you achieve this.

1.8.2. Overlays examples

To see overlays simple examples, go to the Simple examples - live demo You will find out how to add overlays to BPMN elements and how to apply style to them.

Overlay

Simple overlay example.

For the more complete example, please go to Monitoring of all process instances - live demo. This demo shows how to add execution time and frequency data on diagram elements.

Monitoring

Monitoring of all process instances demo, execution time and frequency displayed on BPMN elements.

2. Supported BPMN Elements

The BPMN support roadmap is available in GitHub milestones

The following presents BPMN elements that can be rendered by the bpmn-visualization and states which is their rendering status i.e. if the BPMN elements are rendered with their final shapes.

Legend for rendering status
  • considered as stable (only minor changes may occur)

  • early access (1st attempt)

  • experimental (subject to change)

  • no status means that are arbitrary rendering is used (i.e. not following the BPMN specification requirements), generally using a dedicated color to identify the shape among others

2.1. Containers

Table 2. Containers
Name Rendering Comments

Lane

Sub lanes are also supported

Pool

2.2. Activities

Table 3. Activities
Name Rendering Icon Comments

Abstract Task

Business Rule Task

Business rule icon

Manual Task

Manual rule icon

Icon may be subject to change+ icon: the task icon is derived from the noun project 'hand' icon by João Miranda, licensed as Creative Commons CCBY 3.0

Receive Task

Receive rule icon

Icon may be subject to change

Script Task

Script rule icon

Icon may be subject to change
icon: the task icon is derived from the noun project 'script' icon by Sérgio Filipe Cardoso Pires, licensed as Creative Commons CCBY 3.0

Send Task

Send rule icon

Icon may be subject to change

Service Task

Service rule icon

Icon may be subject to change
icon: the task icon is derived from the draw.io bpmn mxgraph stencil

User Task

User rule icon

Icon may be subject to change
icon: the task icon is derived from the flaticon 'employees' icon "Icons made by freepik from https://www.flaticon.com"

Call Activity calling a Process

Call Activity calling a Global Task

Call Activity calling a Global Business Rule Task

Call Activity calling a Global Manual Task

Call Activity calling a Global Script Task

Call Activity calling a Global User Task

Embedded Sub-Process

Event Sub-Process

Collapsed sub-process :
- Missing start event icon

Table 4. Markers
Name Rendering Icon Comments

Loop Marker

Loop icon

The icon is derived from the loop of draw.io

Sequential Multi-Instance Marker

Sequential Multi Instance icon

Parallel Multi-Instance Marker

Parallel Multi Instance icon

Notes about markers

  • The size of the marker icons will be set to a fixed size later

  • The marker icon of the collapsed activities may be subject to change

2.3. Events

The event definition can be defined on the event or on the definitions.

Note: the following events use icons derived from existing solutions

Table 5. Start Events
Name Rendering Icon Comments

None Start Event

Conditional Start Event

Conditional icon

The stroke & icon width may be adjusted

Message Start Event

Message icon

The stroke & icon width may be adjusted

Signal Start Event

Signal icon

The stroke & icon width may be adjusted

Timer Start Event

Timer icon

The icon width may be adjusted

Table 6. Event Sub-Process Interrupting Start Events
Name Rendering Icon Comments

Compensation Interrupting Start Event

Compensation icon

The stroke & icon width may be adjusted

Conditional Interrupting Start Event

Conditional icon

The stroke & icon width may be adjusted

Error Interrupting Start Event

Error icon

The stroke & icon width may be adjusted

Escalation Interrupting Start Event

Escalation icon

The stroke & icon width may be adjusted

Message Interrupting Start Event

Message icon

The stroke & icon width may be adjusted

Signal Interrupting Start Event

Signal icon

The stroke & icon width may be adjusted

Timer Interrupting Start Event

Timer icon

The icon width may be adjusted

Table 7. Event Sub-Process Non-Interrupting Start Events
Name Rendering Icon Comments

Conditional Non-interrupting Start Event

Conditional icon

The stroke & icon width may be adjusted

Escalation Non-interrupting Start Event

Escalation icon

The stroke & icon width may be adjusted

Message Non-interrupting Start Event

Message icon

The stroke & icon width may be adjusted

Signal Non-interrupting Start Event

Signal icon

The stroke & icon width may be adjusted

Timer Non-interrupting Start Event

Timer icon

The icon width may be adjusted

Table 8. Intermediate Catch Events
Name Rendering Icon Comments

Conditional Intermediate Catch Event

Conditional icon

The stroke & icon width may be adjusted

Link Intermediate Catch Event

Link icon

The stroke & icon width may be adjusted

Message Intermediate Catch Event

Message icon

The stroke & icon width may be adjusted

Signal Intermediate Catch Event

Signal icon

The stroke & icon width may be adjusted

Timer Intermediate Catch Event

Timer icon

The icon width may be adjusted

Table 9. Intermediate Throw Events
Name Rendering Icon Comments

None Intermediate Throw Event

The stroke width may be adjusted

Compensation Intermediate Throw Event

Compensation icon

The stroke & icon width may be adjusted

Escalation Intermediate Throw Event

Escalation icon

The stroke & icon width may be adjusted

Link Intermediate Throw Event

Link icon

The stroke & icon width may be adjusted

Message Intermediate Throw Event

Message icon

The stroke & icon width may be adjusted

Signal Intermediate Throw Event

Signal icon

The stroke & icon width may be adjusted

Table 10. Interrupting Boundary Events
Name Rendering Icon Comments

Cancel Interrupting Boundary Event

Cancel icon

The stroke & icon width may be adjusted

Compensation Interrupting Boundary Event

Compensation icon

The stroke & icon width may be adjusted

Conditional Interrupting Boundary Event

Conditional icon

The stroke & icon width may be adjusted

Error Interrupting Boundary Event

Error icon

The stroke & icon width may be adjusted

Escalation Interrupting Boundary Event

Escalation icon

The stroke & icon width may be adjusted

Message Interrupting Boundary Event

Message icon

The stroke & icon width may be adjusted

Signal Interrupting Boundary Event

Signal icon

The stroke & icon width may be adjusted

Timer Interrupting Boundary Event

Timer icon

The stroke & icon width may be adjusted

Table 11. Non-interrupting Boundary Events
Name Rendering Icon Comments

Conditional Non-interrupting Boundary Event

Conditional icon

The stroke & icon width may be adjusted

Escalation Non-interrupting Boundary Event

Escalation icon

The stroke & icon width may be adjusted

Message Non-interrupting Boundary Event

Message icon

The stroke & icon width may be adjusted

Signal Non-interrupting Boundary Event

Signal icon

The stroke & icon width may be adjusted

Timer Non-interrupting Boundary Event

Timer icon

The stroke & icon width may be adjusted

Table 12. End Events
Name Rendering Icon Comments

None End Event

The stroke width may be adjusted

Cancel End Event

Cancel icon

The icon width may be adjusted

Compensation End Event

Compensation icon

The icon width may be adjusted

Error End Event

Error icon

The icon width may be adjusted

Escalation End Event

Escalation icon

The icon width may be adjusted

Message End Event

Message icon

The stroke & icon width may be adjusted

Signal End Event

Signal icon

The stroke & icon width may be adjusted

Terminate End Event

Terminate icon

The stroke width may be adjusted

2.4. Flows

Table 13. Flows
Name Rendering Comments

Sequence Flow

Subject to change: arrow size/form and position endpoint

Default Sequence Flow

Subject to change: arrow size/form and position endpoint
marker is derived from dash marker of draw.io

Conditional Sequence Flow

Subject to change: arrow size/form and position endpoint

Message Flow

  • No message: Subject to change: arrow size/form and position endpoint

  • Initiating message: To do

  • Non-initiating message: To do

Way Points

Subject to change: paths may be rounded

2.5. Gateways

Table 14. Gateways
Name Rendering Icon Comments

Exclusive

Exclusive icon

Icon may be subject to change

Inclusive

Inclusive icon

Icon may be subject to change

Parallel

Parallel icon

Icon may be subject to change

Event-Based

Event-Based icon Exclusive Event-Based icon Parallel Event-Based icon

Support the event gateway type (Exclusive and Parallel) and the instantiate status

2.6. Labels

Table 15. Labels
Name Rendering Comments

Shape Label

Edge Label

2.7. Artifacts

Table 16. Artifacts
Name Rendering Comments

Group

Text Annotation

2.8. Associations

Table 17. Associations
Name Rendering Comments

Text Annotation Association

All three directional associations are supported: None, One, Both

2.9. Architecture and Development

2.9.1. Architecture Overview

bpmn-visualization consists on 2 main modules:

  • parsing: read a BPMN source (xml string) and convert it into its own internal Model.

  • rendering: display the BPMN diagrams represented by the internal Model, using the mxGraph library

architecture overview

2.9.2. BPMN Internal Model

Our internal model is based on the BPMN specification.

internal model

2.9.3. BPMN Parsing

2.9.3.1. XML Parser

To parse XML data, we use the fast-xml-parser library.

You can see the implementation in BpmnXmlParser.ts.

2.9.3.2. Json Parser

To parse a JSON data, we use a custom parser.

You can see the implementation in BpmnJsonParser.ts. We have different converters (in the converter folder where the BpmnJsonParser file is) in order to match the BPMN model to our internal model.

2.9.4. mxGraph Integration

The mxGraph integration is in charge of rendering the BPMN diagrams, by filling the mxGraph model from the BPMN model.

It also provides the Diagram Navigation support.

For more details, see the development documentation.

2.9.5. Development