Request JSON

The Request JSON is used for the CalculateLayout endpoint of the Symbio-Graphic-Service. Layout calculation can be requested for

• the calculation type cxn (connection; route for a single connection path from a source node to a target node) and
• the calculation type flow (process flow; directed graph with any number of nodes and edges).

From now on the description refers to the calculation type flow.

Table of contents

• 1.0 - General structure of the Request JSON
• 2.0 - The diagram meta-information part of the Request JSON
  • 2.1 - How it typically looks like
  • 2.2 - The requested result type
  • 2.3 - The requested calculation type
  • 2.4 - The configurations
• 3.0 - The context part of the Request JSON (diagram as a whole)
  • 3.1 - How it typically looks like
  • 3.2 - Context informations
• 4.0 - The content part of the Request JSON (containing the nodes and edges collections)
  • 4.1 - How it typically looks like
  • 4.2 - The nodes collection
  • The laneRelevantRelated collection
  • 4.3 - The edges collection
• 5.0 - The pools part of the Request JSON
  • 5.1 - How it typically looks like
  • 5.2 - The pool tuning
• 6.0 - The elements part of the Request JSON
  • 6.1 - How it typically looks like for events
  • 6.2 - How it typically looks like for tasks
  • 6.3 - How it typically looks like for roles
  • 6.4 - How it typically looks like for data --- REWORK STOPED HERE
• 7.0 Understanding the correlation of nodes / edges and elements by examples
  • Sample 1 (a node/shape and the underlaying element vs. the BPMN equivalent)

1. - General structure of the Request JSON

The Request JSON (for calculation type flow) must provide all necessary information to calculate a layout (and optionally render a graphic, in the case the result type is esvg, svg, sesvg or ssvg) of a process flow (directed graph with any number of nodes and edges).

Disclaimer: The following comparison between the Request JSON and BPMN is made not because the two formats perform a similar task, but because they convey similar content: Process flows.

{
  "result": "json",
  "calculation": "flow",
  "configurations": [
    ...
  ],

  "context": {
    ...
  },

  "content": {
    "nodes": [
      {
        ...
      },
      ...
    ],
    "edges": [
      {
        ...
      },
      ...
    ]
  },

  "pools": [
    ...
  ],

  "elements": [
    ...
  ]
}

<definitions>

  <bpmndi:BPMNDiagram>
    ...
    ...

    <bpmndi:BPMNPlane>

      <bpmndi:BPMNShape>
      ...
      </bpmndi:BPMNShape>
      ...


      <bpmndi:BPMNEdge>
      ...
      </bpmndi:BPMNEdge>
      ...

    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>

  <collaboration>
      ...
  </collaboration>

  <process>
      ...
  </process>
</definitions>

2.0 - The diagram meta-information part of the Request JSON

2.1 - How it typically looks like

  "result": "json",
  "calculation": "flow",
  "configurations": [
    {
      "layoutType": "flow",
      "lcid": 1031,
      "vertical": true
    }
  ]
























.

  "result": "json",
  "calculation": "flow",
  "configurations": [
    {
      "layoutType": "flow",
      "lcid": 1031,
      "vertical": true
    },
    {
      "layoutType": "flow",
      "lcid": 1031,
      "vertical": false
    },
    {
      "layoutType": "swimlane-roles",
      "lcid": 1031,
      "vertical": true
    },
    {
      "layoutType": "swimlane-roles",
      "lcid": 1031,
      "vertical": false
    },
    {
      "layoutType": "swimlane-apps",
      "lcid": 1031,
      "vertical": true
    },
    {
      "layoutType": "swimlane-apps",
      "lcid": 1031,
      "vertical": false
    }
  ]

2.2 - The requested result type

The currently suported result types for the calculation type flow are

• json (JSON, the recommended result type) - used in case the resulting JSON should be parsed to post-process the calculation result and log messages are not desired,
• ejson (JSON, enhanced with additional information) - used in case the resulting JSON should be parsed to post-process the calculation result and log messages are desired,
• esvg (HTML embedded SVG, enhanced with additional information) - used in case the resulting HTML has to be displayed directly (e. g. in a test app) and log messages are desired,
• svg (HTML embedded SVG, without additional information) - used in case the resulting HTML has to be displayed directly (e. g. in a test app) and log messages are not desired,
• sesvg (stand-alone SVG, enhanced with additional information) - used in case the resulting SVG has to be embedded into a custom HTML page and log messages are desired and
• ssvg (stand-alone SVG, without additional information) - used in case the resulting SVG has to be embedded into a custom HTML page and log messages are not desired

2.3 - The requested calculation type

The currently suported calculation types are

• cxn (route for a single connection path from a source node to a target node)- used to calculate one single shape-to-shape connection path and
• flow (directed graph with any number of nodes and edges)- used to calculate a directed graph, that represents a process flow.

The calculation type cxn supports all result types.
The calculation type flow supports the result types 1. ... 4. only.

2.4 - The configurations

The configurations collection can currently contain one or six configuration(s).
One configuration is provided, of only one of the following layouts hast to be calculated:

• The layoutType set to flow (layout without pools / lanes) and vertical set to true .
• The layoutType set to flow (layout without pools / lanes) and vertical set to false .
• The layoutType set to swimlane-roles (layout with pools / lanes, lanes are based on roles or organizational units) and vertical set to true .
• The layoutType set to swimlane-roles (wlayout ith pools / lanes, lanes are based on roles or organizational units) and vertical set to false .
• The layoutType set to swimlane-apps (layout with pools / lanes, lanes are based on application systems and fall back to roles or organizational units) and vertical set to true .
• The layoutType set to swimlane-apps (layout with pools / lanes, lanes are based on application systems and fall back to roles or organizational units) and vertical set to false .

All six configurations (three layoutType values multiplied with two vertical direction values) are provided, if all of the above listed layouts have to be calculated.

3.0 - The context part of the Request JSON (diagram as a whole)

The context represents the diagram (process) to layout as a whole. BPMN contains this data within the <bpmndi:BPMNDiagram> tag.

3.1 - How it typically looks like

  "context": {
    "id": "3783f2a0-99c0-4120-a639-4acfd59a8021",
    "properties": {
      "elementTypeKind": "business",
      "facetName": "processes",
      "state": "inProcess",
      "stereoType": "f5942ab4-2365-4a07-8a3f-04d10fb3b870",
      "type": "subProcess",
      "versionId": "2a536296-d3c7-47cf-8d2e-511eaf5b666d"
    },
    "attributes": [
      {
        "key": "links",
        "type": "linksValue",
        "values": [
          {
            "lcid": 127,
            "value": {
              "links": [
                {
                  "locator": "www.duckduckgo.com",
                  "title": "Find"
                }
              ]
            }
          }
        ]
      },
      {
        "key": "majorVersion",
        "type": "integer",
        "values": [
          {
            "lcid": 127,
            "value": 0
          }
        ]
      },
      {
        "key": "minorVersion",
        "type": "integer",
        "values": [
          {
            "lcid": 127,
            "value": 1
          }
        ]
      },
      {
        "key": "name",
        "type": "multiLineText",
        "values": [
          {
            "lcid": 1031,
            "value": "GRAPHIC-API"
          }
        ]
      }
    ]
  }

3.2 - Context informations

Typical information provided for the diagran (process) are:

• The id contains the unique identity of the diagram, it is provided for informational purposes only and is passed on to the Result JSON .
• The properties contains a collection of optional information.
• The attributes contains a collection of information, that are used to be displayed when the diagram is rendered. Therefore these informations are passed on to the Result JSON . Typically the text attributes are provided in multiple languages.

4.0 - The content part of the Request JSON (containing the nodes and edges collections)

The content contains the nodes and edges (in the meaning of nodes and edges within a directed graph) of the diagram (process). Typically the nodes and edges are displayed as soon als the layout is rendered. Therefore the nodes require the calculation of their positions and the edges require the calculation of their routes in order to be written to the Result JSON including the positions and routes.

4.1 - How it typically looks like

  "content": {
    "nodes": [
      {
        "shapeId": "e85e124a-86aa-4fe6-aaaf-4c5707215461",
        "elementId": "5dd9be26-b592-4e02-b4b0-e508a7844e27",
        "properties": {
          "type": "evStart"
        },
        "laneRelevantRelated": [
          {
            "elementId": "c61aaf77-5d75-4ff6-a567-d9662715c46d",
            "layoutTypes": [
              "swimlane-roles",
              "swimlane-apps"
            ]
          }
        ]
      },
      ...
    ],
    "edges": [
      {
        "shapeId": "ad711e08-3fd4-44b6-bac8-518e72a005c2",
        "elementId": "3bf7c2cf-a70e-49d3-9377-301bfebec515",
        "properties": {
          "type": "crt1",
          "source": {
            "shapeId": "542e5c76-5482-4b4d-bf56-8a6d927e6a6b"
          },
          "target": {
            "shapeId": "343b15d4-3d51-4b1b-9bef-4b3b4889a88f"
          }
        }
      },
      ...
    ],

(see chapter 7.0 Understanding the correlation of nodes / edges and elements by examples below).

4.2 - The nodes collection

Nodes represent the shapes, comparable to BPMN <startEvent> or <task>.

      {
        "shapeId": "e85e124a-86aa-4fe6-aaaf-4c5707215461",
        "elementId": "5dd9be26-b592-4e02-b4b0-e508a7844e27",
        "properties": {
          "pool": {
            "poolId": "c84c7e2e-ea39-4fc8-b2dd-10df2b7c766a"
          },
	  "type": "evStart"
        },
        "laneRelevantRelated": [
          {
            "elementId": "c61aaf77-5d75-4ff6-a567-d9662715c46d",
            "layoutTypes": [
              "swimlane-roles",
              "swimlane-apps"
            ]
          }
        ]
      }

Typical information provided for a node are:

• The shapeId contains the unique identity of the node.
• The elementId contains the unique identity of the element, the node is based on, it is passed on to the Result JSON .
• The properties contains a collection of optional information, which are passed on to the Result JSON .
  • The optional pool contains the assignment of this node to a pool (this assignment is the same for all layouts).
  • The optional type contains the type of the node.
• The laneRelevantRelated contains a collection of elements, that are used to determine the lane the shape is to be assigned to.

The pool assignment

A node can optionally be assigned to a pool. The poolId must refer to an existing pool within the The pools part of the Request JSON .

The laneRelevantRelated collection

Since the Request JSON has to support multiple layouts at once, it is required to provide information about the lane assignment per layout. Therefore the laneRelevantRelated element collection includes for each lane relevant element the information which layoutTypes are supported by a lane relevant element. The values used for the layoutTypes here match the values used for the layoutType within the configurations.

(For details regarding the layoutType values see chapter The configurations above).

Putting it all together For a sample, that shows the correlation between node and element in the Request JSON and in the Result JSON and also in comparison to BPMN see chapter 7.0 Understanding the correlation of nodes / edges and elements by examples and section Sample 1 (a node/shape and the underlaying element vs. the BPMN equivalent).

4.3 - The edges collection

Edges represent the connection between shapes, comparable to BPMN <sequenceFlow>.

    {
        "shapeId": "ad711e08-3fd4-44b6-bac8-518e72a005c2",
        "elementId": "3bf7c2cf-a70e-49d3-9377-301bfebec515",
        "properties": {
          "type": "crt1",
          "source": {
            "shapeId": "542e5c76-5482-4b4d-bf56-8a6d927e6a6b"
          },
          "target": {
            "shapeId": "343b15d4-3d51-4b1b-9bef-4b3b4889a88f"
          }
        }
      }

Typical information provided for an edge are:

• The shapeId contains the unique identity of the node.
• The elementId contains the unique identity of the element, the edge is based on, it is passed on to the Result JSON .
• The properties contains a collection of information, which are processed by the layouter. Every edge must contain a source shapeId and a target shapeId in order to connect two nodes.

5.0 - The pools part of the Request JSON

Pools can be automatically recognized from the nodes collection.

But either if empty pools are to be added or if pools shall be sorted in a distict order the automatic pool recognition is insufficient and the pools must be listed explicitly.

So we have these cases:

• The diagram is to be laid out (and optionally rendered) without pools: The pools part can be left empty.
• The diagram is to be laid out (and optionally rendered) with pools but there are no specicic requirements to the pools: The pools part can be left empty.
• The diagram is to be laid out (and optionally rendered) with pools and an empty pool hast to be added: The pools part must contain the pools in the desired sort order.
• The diagram is to be laid out (and optionally rendered) with pools and the order of the pool has to be distinct: The pools part must contain the pools in the desired sort order.

5.1 - How it typically looks like

This is an example with three pools:

{
  "id": "d5d7ce44-c18f-4119-aa18-8f9e8aa69e85",
  "properties": {
    "type": "bpmnPool",
    "kind": "object",
    "servity": "source"
  },
  "attributes": [{
    "key": "name",
    "type": "multiLineText",
    "values": [
      { "lcid": 1033, "value": "Data source" }
    ]
  }]
},
{
  "id": "03c092c9-b723-4a38-befd-f6f54aef42d6",
  "properties": {
    "type": "bpmnPool",
    "kind": "object"
  },
  "attributes": [{
    "key": "name",
    "type": "multiLineText",
    "values": [
      { "lcid": 1033, "value": "Processing" }
    ]
  }],
  "children": [
      "467cbfa4-ff43-49fe-ac0d-49beda2e07f6",
      "c989af38-3e9e-4693-a284-3801da7696de"
  ]
},
{
  "id": "63cf252b-ed7f-458e-97c3-3b557786eb52",
  "properties": {
    "type": "bpmnPool",
    "kind": "object",
    "servity": "target"
  },
  "attributes": [{
    "key": "name",
    "type": "multiLineText",
    "values": [
      { "lcid": 1033, "value": "Data target" }
    ]
  }]
},
...

The "pools" are of item type "bpmnPool" and of item kind "object".

It is highly recommended to define names for all pools (see "attributes" with "key": "name").

5.2 - The pool servity

One pool should be designated as the default pool so that shapes can be automatically (fall- back) attached to the default pool without explicitly assigning a pool to shapes. This creates a fail-safe behavior and makes the JSON code shorter. To identify the default pool you can:

• Mark all pools except the default pool as "source" ( "servity": "source" ) or "target" ( "servity": "target" ). In case of multiple matches, the last one wins.
• Mark the default pool ( "servity": "default" ). In case of multiple matches, the last one wins.
• In case no pool is designated as the default pool , the centre pool (count / 2) is used.

In the case that a pool should contain multiple lanes and the lanes should be in a defined order, it is recommended to define the lanes as a list of children (see "children"). The ids, specified in the list of children, must refer to existing items, that are typically roles, groups, application systems or application services.

Nevertheless, it is possible to provide the pools without any tuning at all and let the Symbio-Graphic-Service do all the tuning.

6.0 - The elements part of the Request JSON

The elements collection contains all elements, that

• underlay a node or
• are connected to nodes as related or laneRelevantRelated elements .

6.1 - How it typically looks like for events

{
  "id":
    "B63F2971E571B69F49AAD5B0733302FA",
  "properties": {
    "type": "evStart",
    "kind": "OBJ",
    "evType": "throwSignal"
  },
  "attributes": [
    {
      "key": "name",
      "values": [
        { "lcid": 1033,
          "value": "Start" }
      ]
    },
      ...
  ]
}

<bpmn:startEvent
 id="StartEvent_0034tgy"
 name="Goods arrived">
  <bpmn:outgoing>
    SequenceFlow_0pern26
  </bpmn:outgoing>
</bpmn:startEvent>
...

6.2 - How it typically looks like for tasks

{
  "id":
    "bcf7ab71d86145919a5a0a570fa2beed",
  "properties": {
    "type": "task",
    "kind": "OBJ",
    "typeDisplayName": "Task"
  },
  "attributes": [
    {
      "key": "name",
      "values": [
        { "lcid": 1033,
          "value": "Task-01" }
      ]
    },
    ...
  ],
  "related": [
    {
      "key": "accountableRole",
      "shortKey": "A",
      "versionIds": [
    "35f4cfb5437e4f1d8fd072859648e183"
      ]
    },
    ...
  ]
}

<bpmn:task
 id="Activity_16oto7s"
 name="Process goods">
  <bpmn:incoming>
    SequenceFlow_0pern26
  </bpmn:incoming>
  <bpmn:outgoing>
    SequenceFlow_1vdst1y
  </bpmn:outgoing>
</bpmn:task>
...

6.3 - How it typically looks like for roles

{
  "id":
    "ed6645df50804e6f9ab235121c5ea567",
  "versionId":
    "a2a8e8e8090f464fac78bec8b851c963",
  "properties": {
    "kind": "OBJ",
    "stereoType": "extern",
    "type": "role",
    "typeDisplayName": "Role"
  },
  "attributes": [
    {
      "key": "name",
      "values": [
        { "lcid": 1033,
          "value": "DP officer" }
      ]
    },
    ...
  ]
}

<bpmn:laneSet
  id="LaneSet_1n0pzhw">
  <bpmn:lane
    id="Lane_0w5mswf"
    name="MyLane-01">
    ...
  </bpmn:lane>
</bpmn:laneSet>
  

6.4 - How it typically looks like for data

{
  "id":
    "480439511168499d8bc5a1fda3285542",
  "versionId":
    "1129e2af0a174064a79849002e1ceb56",
  "properties": {
    "kind": "OBJ",
    "type": "system",
    "typeDisplayName": "Application"
  },
  "attributes": [
    {
      "key": "name",
      "values": [
        { "lcid": 1033,
          "value": "Accounting portal" }
      ]
    },
    ...
  ]
},
{
  "id":
    "9487278f25464394aff9e68bef9b2535",
  "versionId":
    "f1c69f8d04ad4e9e82f11f0465f536a6",
  "properties": {
    "kind": "OBJ",
    "type": "inOut",
    "typeDisplayName": "Input/Output"
  },
  "attributes": [
    {
      "key": "name",
      "values": [
        { "lcid": 1033,
          "value": "Inbound quotation" }
      ]
    },
    ...
  ]
}

<bpmn:dataStoreReference
  id=
    "DataStoreReference_07dozvu"
  name=
    "Data-Store" />
  















<bpmn:dataObjectReference
  id=
    "DataObjectReference_1unf7qz"
  name=
    "Data-Object"
  dataObjectRef=
    "DataObject_1lq9toa" />
<bpmn:dataObject
  id=
    "DataObject_1lq9toa" />

{
	"id": "a6743dd3-8881-4d22-bfe7-0b7f703097c8",
	"properties": {
            "itemId": "9bc5994a-f64f-431f-a631-1ff405f22643",
            "type": "evStart",
            "poolId": "6496cb0f-8763-4e27-a8dd-77870be94fd5"
	}
}

Referencing the shape's underlying item is done with "itemId" : "9bc5994a-f64f-431f-a631-1ff405f22643".
The (optional) second reference, "poolId": "6496cb0f-8763-4e27-a8dd-77870be94fd5", defines membership of the shape in a pool.

Here is the shape underlying item:

{
  "id": "9bc5994a-f64f-431f-a631-1ff405f22643",
  "properties": {
    "type": "evStart",
    "kind": "OBJ",
    "evType": "throwSignal"
  },
  "attributes": [{
    "key": "name",
    "values": [
      { "lcid": 1033, "value": "recognize hunger" }
    ]
  }]
}

The type is provided via the "properties" property array property "type".
In addition to that the kind (which determines whether it is a shape or a edge) is provided via the "properties" property array property "kind".
In case the item (and thus the shape as well) is defined more specifically, the "properties" property array might contain a property "evType" or "funcType" ore "funcMarker".
The text to display is defined within the "attributes" property array object with the "key": "name". Since the request JSON supports multiple languages, the name value is provided by the "values" property array, that can hold distinct value objects for different cultures.

Edges and edge items

The design of edge content elements is intended to be minimalistic.
Here is an example:

{
	"id": "e5dfd46e-8720-408e-b760-171038da9f6d",
	"properties": {
		"itemId": "6496cb0f-8763-4e27-a8dd-77870be94fd5",
		"sourceId": "a6743dd3-8881-4d22-bfe7-0b7f703097c8",
		"targetId": "75397704-e829-49b3-a40c-02379fb0b393",
		"type": "activ1"
	}
}

Referencing the edge's underlying item is done with "itemId" : "6496cb0f-8763-4e27-a8dd-77870be94fd5".
The is no reference to a pool, since edges can cross lanes and pools.
The referencing of the source and target shapes is done with "sourceId": "a6743dd3-8881-4d22-bfe7-0b7f703097c8" and "targetId": "75397704-e829-49b3-a40c-02379fb0b393". An edge must always hold a source and a target shape reference.

Here is the edge underlying item:

{
    "id": "6496cb0f-8763-4e27-a8dd-77870be94fd5",
    "properties": {
        "kind": "CXN",
        "sourceId": "9bc5994a-f64f-431f-a631-1ff405f22643",
        "targetId": "b0907b38-e8e4-42f3-bc0a-d3e83ae2a1a7",
        "type": "activ1"
	},
    "attributes": [{
        "key": "cxnRole",
        "values": [
        { "lcid": 1033, "value": "yes" }
        ]
    }]
}

The type is provided via the "properties" property array property "type".
In addition to that the kind (which determines whether it is a shape or a edge) is provided via the "properties" property array property "kind".
The text to display is defined within the "attributes" property array object with the "key": "cxnRole". Since the request JSON supports multiple languages, the name value is provided by the "values" property array, that can hold distinct value objects for different cultures.

Lane items

In the case that the diagram is to be laid out and rendered with lanes, the lanes are automatically recognized by the fact, that they are related to structure building items via the configured laneRelevant relation (see "laneRelevant": "responsible" within configurations property). The lanes must not be of any of any specific item type (see "type": "..."), but they must be of item kind "OBJ" (see "kind": "OBJ") and must not be of any of the structure building item types (like "type": "func", "type": "evStart", "type": "evIntermediate", "type": "evEnd", "type": "ruleXor", "type": "ruleOr", "type": "ruleAnd" or "type": "condition").

In the case that multiple lanes should be contained in a pool and the lanes should be in a defined order, it is recommended to define the lanes as a list of children (see "children") within the pool. The ids, specified in the list of children, must refer to existing lane (items), that are typically roles, groups, application systems or application services.

Understanding the correlation of nodes / edges and elements by examples

The biggest part of the necessary information is the description of the nodes and edges. In order to understand the nodes and edges within the Request JSON, comparing their data to BPMN and the expected outcome Result JSON could be helpful.

Disclaimer: The following comparison between the Request JSON, BPMN and the Result JSON is made not because the two formats perform a similar task, but because they convey similar content: Process flows.

While the Request JSON contains only the necessary information for automatic layout calculation and rendering, the BPMN also already contains all information for rendering (like position and size of shapes or the interpolation points of edges), which comes closer to the Result JSON.

For basics about the nodes see section The nodes collection.

Sample 1 (a node/shape and the underlaying element vs. the BPMN equivalent)

{
  "shapeId": "fd4e1872-8742-4bfa-9c4f-b271ec81c73f",
  "elementId": "ab99ac91-be7d-43c4-955d-04324360fbdf",
  "properties": {
    "type": "evStart"
  },
  "laneRelevantRelated": [
    {
      "elementId": "c61aaf77-5d75-4ff6-a567-d9662715c46d",
      "layoutTypes": [
        "swimlane-roles",
        "swimlane-apps"
      ]
    }
  ]
}












































.

{
  "id": "ab99ac91-be7d-43c4-955d-04324360fbdf",
  "properties": {
    "kind": "object",
    "type": "evStart",
    "typeDisplayName": "Start"
  },
  "attributes": [
    {
      "key": "description",
      "type": "singleLineText",
      "values": [
        {
          "lcid": 1031,
          "value": "Goods arrived"
        }
      ]
    },
    {
      "key": "evStartTrigger",
      "type": "selectionValue",
      "values": [
        {
          "lcid": 127,
          "value": "evTriggerNoneIntSub"
        }
      ]
    },
    {
      "key": "evType",
      "type": "selectionValue",
      "values": [
        {
          "lcid": 127,
          "value": "evTypeMessage"
        }
      ]
    },
    {
      "key": "name",
      "type": "multiLineText",
      "values": [
        {
          "lcid": 1031,
          "value": "Start-01"
        }
      ]
    }
  ],
  "related": [
    {
      "key": "executiveRole",
      "shortKey": "R",
      "versionIds": [
        "9700e981-1c36-4536-a05b-592aa2fd6219"
      ]
    }
  ]
},

<bpmndi:BPMNShape id="IntermediateThrowEvent_0iyvpzm_di" bpmnElement="IntermediateThrowEvent_0iyvpzm">
  <dc:Bounds x="458" y="313" width="36" height="36" />
  <bpmndi:BPMNLabel>
    <dc:Bounds x="464" y="353" width="24" height="12" />
  </bpmndi:BPMNLabel>
</bpmndi:BPMNShape>

<g>
  <!-- evStart(evStart) /ID:fd4e1872-8742-4bfa-9c4f-b271ec81c73f /ItemID:ab99ac91-be7d-43c4-955d-04324360fbdf -->
  <!-- evStart /W:160 /H:160 -->
  <ellipse cx="124.7244" cy="63.49606" rx="22.677164" ry="22.677164"
    style="shape-rendering:auto; stroke:#808080; stroke-width:1px; stroke-linecap:round;
    stroke-dasharray:; stroke-opacity:1; fill:#FFFFFF; fill-opacity:1;"></ellipse>
  <!-- ##ATS##_evTypeShapeCatchMessage /W:80 /H:80 -->
  <rect x="113.5" y="55.5" rx="2.2677164" ry="2.2677164" width="22" height="16"
    style="stroke:#000000; stroke-width:1px; stroke-linecap:round; stroke-dasharray:;
    stroke-opacity:1; fill:#FFFFFF; fill-opacity:1;"></rect>
  <path d="M113.224396,57.66535L122.295265,65.602356C124.56298,66.73621 124.56298,66.73621 
    126.830696,65.602356L135.90157,57.66535" style="shape-rendering:auto; stroke:#000000;
    stroke-width:1px; stroke-linecap:round; stroke-dasharray:; stroke-opacity:1;
    fill:transparent; fill-opacity:0.0;"></path>
  <text class="" x="124.5" y="99.92084" text-anchor="middle"
    style="fill:#444444;font-family:Segoe UI;font-weight:400;font-style:normal;font-size:9pt;text-decoration:none;">
    <tspan class="" x="124.5" dy="0">Goods</tspan><tspan class="" x="124.5" dy="15">arrived</tspan></text>
</g>

{
  "id": "ab99ac91-be7d-43c4-955d-04324360fbdf",
  "properties": {
    "column": 0.0,
    "evType": "evTypeCatchMessage",
    "height": 50,
    "kind": "shape",
    "row": 0.0,
    "type": "evStart",
    "typeDisplayName": "Start",
    "width": 50,
    "x": 112.5,
    "y": 45.0
  },
  "attributes": [
    {
      "key": "evStartTrigger",
      "values": [
        { "lcid": 127, "value": "evTriggerStd" }
      ]
    },
    {
      "key": "name",
      "values": [
        { "lcid": 1033, "value": "Goods arrived" }
      ]
    }
  ],
  "attributeDisplays": [
    {
      "key": "name",
      "width": 70.0,
      "height": 34.0625,
      "xOffset": -10.0,
      "yOffset": 60.0,
      "rotation": 0.0,
      "horizontalAlignment": "center",
      "verticalAlignment": "top"
    }
  ],
  "related": [
    {
      "key": "executiveRole",
      "shortKey": "R",
      "ids": [
        "4c71d84e-2084-4dc1-bda4-dd2ff664aba4"
      ]
    }
  ]
}

Sample 2 (an edge)

For basics about the edges see section The edges collection.

BPMN sample for interpolation points of an edge

<bpmndi:BPMNEdge id="SequenceFlow_1vmk1br_di" bpmnElement="SequenceFlow_1vmk1br">
  <di:waypoint xsi:type="dc:Point" x="209" y="331" />
  <di:waypoint xsi:type="dc:Point" x="245" y="331" />
  <bpmndi:BPMNLabel>
    <dc:Bounds x="182" y="310" width="90" height="12" />
  </bpmndi:BPMNLabel>
</bpmndi:BPMNEdge>