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Examples of non-repeatable workflows are often used in AppFacets.

Jira Legacy

showSummary	false
server	JIRA (mqidentity.atlassian.net)
serverId	77fb3325-4051-36d9-bcc7-761f62050707
key	DOCS-36

Code Block

language	xml
title	Non-repeatable workflow example
linenumbers	true

placeholder for example of non-repeatable workflow<AppFacet name="CSVLoader">
    <String name="destModelName" />
    <String name="DriverId" />
    <String name="ParkingLotId" />
    <String name="fileName" KnownBy="csvLoaderAc" Update="auto" />
    <Action name="csvLoaderAc" documentation="Data Facet to load CSV Data">
        <Workflow Limit="1" Live="1" Timeout="-1">
            <Task name="Main">
                <Event name="Argument" as="ActionArgument" />
                <Invoke name="CSVDataLoader" waitFor="Argument">
                    <FacetScript>
                        <Log Message="Loading file..."/>
                        <LoadFromCSV fileName="[%:Event.Argument.fileName.Value:%]" 
                                     destModelName="[%:Event.Argument.destModelName.Value:%]"
                                     DriverId="[%:Event.Argument.DriverId.Value:%]"
                                     ParkingLotId="[%:Event.Argument.ParkingLotId.Value:%]" />
                        <Log Message="Loading complete!!!"/>
                    </FacetScript>
                </Invoke>
                <Output name="ActionResult">
                    <Value>
                        <Log Message="Output file name: [%:Event.Argument.fileName.Value:%]"/>
                        <fileName>[%:Event.Argument.fileName.Value:%]</fileName>
                    </Value>
                </Output>
            </Task>
        </Workflow>
    </Action>
</AppFacet>

b. Repeatable (multi-run, stream) workflows

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Note

title	Use While = "true" in the first task

Due to the current compiler limitation, you must use While = "true" for the first task that appears in your workflow definition (source code) in order for the compiler to recognize that this is a repeatable workflow. You do not need to specify While = "true" for the subsequent tasks in the same workflow definition.

Code Block

language	xml
title	Repeatable workflow example
linenumbers	true

<ThingFacet Name="TempFacetSerial">
    <Number Name="tempValue" update="auto" KnownBy="SerialReadAction" />
    <String Name="unit" default="Celsius" Documentation="Celsius or Fahrenheit" />
    <String Name="peripheral" />
    <String Name="interfacePort" />
    <String Name="interface" />
    <String Name="uniqueId" default="56789" />
    <String Name="baudrate" />
    <String Name="format" default="ascii" />
    <String Name="operation" />
    <String Name="payload" />

    <Action Name="SerialReadAction" Documentation="Start the serial port">
        <Workflow Limit="1" Live="1" Timeout="-1">
            <Task name="Main" while="true">
                <Event name="Argument" as="ActionArgument" />

                <Invoke name="InvokeSerialRead" waitFor="Argument" get="perif://">
                    <Message>
                        <Value>
                            <InterfacePort>"[%:Event.Argument.interfacePort.Value:%]"
                            </InterfacePort>
                            <Baudrate>"[%:Event.Argument.baudrate.Value:%]"</Baudrate>
                            <Interface>"[%:Event.Argument.interface.Value:%]"</Interface>
                            <UniqueId>"[%:Event.Argument.uniqueId.Value:%]"</UniqueId>
                            <Operation>"[%:Event.Argument.operation.Value:%]"</Operation>
                            <format>"[%:Event.Argument.format.Value:%]"</format>
                            <Payload>"[%:Event.Argument.payload.Value:%]"</Payload>
                            <Peripheral>"[%:Event.Argument.peripheral.Value:%]"</Peripheral>
                        </Value>
                    </Message>
                </Invoke>
                <Output name="Result" as="ActionResult">
                    <Value>
                        <tempValue>
                            [%:Invoke.InvokeSerialRead.Message.Value/number(
                            substring-before(substring-after("[%:Invoke.InvokeSerialRead.Message.Value:%]",
                            '#TCB:'), '#')):%]
                        </tempValue>
                    </Value>
                </Output>

            </Task>
        </Workflow>
    </Action>
</ThingFacet>

Non-waiting versus externally-activated workflows

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Instances of such workflow are started right after they are created. This is done by ensuring that all the input values of the workflow's initial task(s) have their values assigned in your source code (versus waiting for external events to give value). They are only useful if they are doing something or communicating with some other entities [en-masse] which is difficult with non-repeatable workflows.

Jira Legacy

showSummary	false
server	JIRA (mqidentity.atlassian.net)
serverId	77fb3325-4051-36d9-bcc7-761f62050707
key	DOCS-36

Code Block

language	xml
title	Example of non-waiting workflow
linenumbers	true

Placeholder for example of non-waiting workflow<Action name="SetOutput">
  <Workflow Limit="1" Live="1" Timeout="-1">
    <Task name="Step1">
      <Input name="Argument" type="string" kind="literal" value="Hello World!"/>
      <Output name="Result" type="string" value="Step1 says '[:Input.Argument:]'"/>
    </Task>
    <Task name="Step2">
      <Input name="Argument" type="string" value="Step1.Result"/>
      <Output name="Result" type="string" value="Step2 says that '[:Input.Argument:]'"/>
    </Task>
    <Task name="Step3">
      <Input name="Argument" type="string" value="Step2.Result"/>
      <Output name="Result" type="string" value="Step3 says that '[:Input.Argument:]'"/>
    </Task>
    <Task name="Step4">
      <Input name="Argument" type="string" value="Step3.Result"/>
      <Output name="Result" type="string" value="Step4 says that '[:Input.Argument:]'"/>
    </Task>
  </Workflow>
</Action>

b. Externally-activated workflows

These are workflows which have explicit “event handler”. Instances of these workflows wait for the external event to come and then start ("external" here means external to the workflow itself). The "event handler" is written as "Event" in the workflow definition. In ThingFacet (and AppFacet) workflows, the Event is typically the ActionArgument, which is triggered by the modification of actionable attributes of the model facet. Jira LegacyshowSummaryfalseserverJIRA (mqidentity.atlassian.net)serverId77fb3325-4051-36d9-bcc7-761f62050707keyDOCS-36

Code Block

language	xml
title	Example of externally-activated workflow
linenumbers	true

Placeholder for example of externally-activated workflows.<Action name="SetOutput">
  <Workflow Limit="1" Live="1" Timeout="-1">
    <Task name="Step1">
      <Event name="Argument" as="ActionArgument" />
      <Output name="Result" type="string" value="Step1 says '[:Event.Argument:]'"/>
    </Task>
    <Task name="Step2">
      <Input name="Argument" type="string" value="Step1.Result"/>
      <Output name="Result" type="string" value="Step2 says that '[:Input.Argument:]'"/>
    </Task>
    <Task name="Step3">
      <Input name="Argument" type="string" value="Step2.Result"/>
      <Output name="Result" type="string" value="Step3 says that '[:Input.Argument:]'"/>
    </Task>
    <Task name="Step4">
      <Input name="Argument" type="string" value="Step3.Result"/>
      <Output name="Result" type="string" value="Step4 says that '[:Input.Argument:]'"/>
    </Task>
  </Workflow>
</Action>

Externally-continued versus internally continued workflows

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These have an invoke with the WaitFor modifier. Instances of such workflows can start, work for a while and then suspend and wait for an event in the middle of task (on the waitFor). Once wait is completed they continue until the next WaitFor or process completion (The "external" here means external to the workflow itself). Jira LegacyshowSummaryfalseserverJIRA (mqidentity.atlassian.net)serverId77fb3325-4051-36d9-bcc7-761f62050707keyDOCS-36

Code Block

language	xml
title	Example of externally-continued workflow
linenumbers	true

Placeholder for example of externally-continued workflow<Action Name="SerialReadAction" Documentation="Start the serial port">
  <Workflow Limit="1" Live="1" Timeout="-1">
    <Task name="Main" while="true">
      <Event name="Argument" as="ActionArgument" />
      <Invoke name="InvokeSerialRead" waitFor="Argument" get="perif://">
        <Message>
          <Value>
            <InterfacePort>
              "[%:Event.Argument.interfacePort.Value:%]"
            </InterfacePort>
            <Baudrate>
              "[%:Event.Argument.baudrate.Value:%]"
            </Baudrate>
            <Interface>
              "[%:Event.Argument.interface.Value:%]"
            </Interface>
            <UniqueId>
              "[%:Event.Argument.uniqueId.Value:%]"
            </UniqueId>
            <Operation>
              "[%:Event.Argument.operation.Value:%]"
            </Operation>
            <format>
              "[%:Event.Argument.format.Value:%]"
            </format>
            <Payload>
              "[%:Event.Argument.payload.Value:%]"
            </Payload>
            <Peripheral>
              "[%:Event.Argument.peripheral.Value:%]"
            </Peripheral>
          </Value>
        </Message>
      </Invoke>
      <Log
           Message="Invoke --> [%:Invoke.InvokeSerialRead.Message.Value.received:%]" />
      <Output name="Result" as="ActionResult">
        <Value>
          <tempValue>
            [%:Invoke.InvokeSerialRead.Message.Value/number(
            substring-before(substring-after("[%:Invoke.InvokeSerialRead.Message.Value:%]",
            '#TCB:'), '#')):%]
          </tempValue>
        </Value>
      </Output>
    </Task>
  </Workflow>
</Action>

b. Internally continued workflows

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In such workflows, it is a good practice to have a Timeout modifier on the workflow.

expand

Workflow instances run on top of pipelines, that is, they use pipelines to be instantiate, trigger or communicate. We call the pipeline that instantiate a workflow instance the originating pipeline. Based on the relationship between the workflow and its originating pipeline, workflow can be categorized into non-repeatable workflows and repeatable workflows.

In non-repeatable workflow, the originating pipeline waits until the workflow completes. In repeating working, the originating pipeline does not wait. The workflow, after being instantiated, may be triggered by a different pipeline.

Code Block

language

xml
title	unused notes

Info

icon	false

Example for Internally continued workflows

<ThingFacet Name="PhidgetRFID">
  <Sid Name="RFIDId" />
  <String Name="ReadTag" Update="auto" KnownBy="PhidgetReadRFIDTagAc" />
  <String Name="WriteTag" KnownBy="PhidgetWriteRFIDTagAc" />
  <String Name="RFIDURL" Default="phid://" />
  <String Name="InterfaceType" />
  <String Name="InterfaceIndex" />
  <Unique Name="RFIDIndex" Value="InterfaceIndex" />
  <DateTime Name="timestamp" Format="$SimpleDateFormat(yyyy-MM-dd'T'HH:mm:ss'Z')" />
  <AA>
    [:#o#Output.ActionArgument:]
  </AA>
  <Action Name="PhidgetReadRFIDTagAc" Documentation="Read the Tag Automatically in the vicinity">
    <Workflow Limit="1" Live="1" Timeout="-1">
      <Task name="Main" while="true">
        <Event name="Argument" as="ActionArgument" />
        <Invoke name="ReadValue" waitFor="Argument"
                get="[%:Event.Argument.RFIDURL.Value:%]" SerialNumber="[%:Event.Argument.InterfaceIndex.Value:%]"
                DeviceType="[%:Event.Argument.InterfaceType.Value:%]" />
        <Output name="Result" as="ActionResult">
          <Value>
            <ReadTag>
              [%:[%:@Output:%]Invoke.ReadValue.Message.Value:%]
            </ReadTag>
          </Value>
        </Output>
      </Task>
    </Workflow>
  </Action>
  <Action Name="PhidgetWriteRFIDTagAc" Documentation="Write the Tag Value to RFID in the vicinity">
    <Workflow Limit="1" Live="1" Timeout="-1">
      <Task name="Main" while="true">
        <Output name="ActionArgument" as="ActionArgument" />
        <Invoke name="WriteValue" waitFor="ActionArgument"
                skip-if="[%:[:AA:].WriteTag/no-value(Value):%]" post="[%:[:AA:].RFIDURL.Value:%]"
                SerialNumber="[%:[:AA:].InterfaceIndex.Value:%]"
                SensorType="WriteTag" DeviceType="[%:[:AA:].InterfaceType.Value:%]">
          <Message Type="text" Value="[%:[:AA:].WriteTag.Value:%]" />
        </Invoke>
        <Output name="Result" as="ActionResult">
          <Value>
            <WriteTag>
              [%:[%:@Output:%]Invoke.WriteValue.Message.Value:%]
            </WriteTag>
          </Value>
        </Output>
      </Task>
    </Workflow>
  </Action>
</ThingFacet>

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Key

Non-waiting versus externally-activated workflows

Externally-continued versus internally continued workflows