Associate multiple thing actions

One can associate multiple actions to a Thingfacet Attribute. You can do this by providing comma separated list of Action names. For example:

Assoicating Multiple Actions

<String name="State" KnownBy="SyncImageAction,SyncPresetAction"/>

Here you can see two actions: SyncPresetAction and SyncImageActon which deal with camera preset and snapshot image respectively. Both the actions update the "State" attribute of a Camera Facet.

Multiple Thing Actions

<!-- Actions -->
<Action Name="SyncPresetAction" Documentation="Synchronize camera state and preset">
  <Workflow Limit="1" Live="1" Timeout="PT20S">
    <Task Name="Main" While="true">
      <Event Name="Argument" As="ActionArgument"/>
      <Invoke Name="SetPreset" waitFor="Argument" skip-if="[%:[:AA:].Preset/no-value(Value):%]" delayAfter="PT5S"
        get="[%:[:AA:].URL.Value:%]/cgi-bin/decoder_control.cgi?[:UP:][%:amp:%]command=15[%:amp:%]sit=[%:[:AA:].Preset.Value:%]"/>
      <Output name="Result" as="ActionResult">
        <Value>
          <State> [%:[%:@Output:%]/if([:POK:]) then 'ON' else 'OFF':%]</State>
          <Preset>[%:[%:@Output:%]/if([:POK:]) then '[%:[:AA:].Preset.Value:%]' else null():%]</Preset>
        </Value>
      </Output>
    </Task>
  </Workflow>
</Action>
<Action name="SyncImageAction" documentation="Synchronize camera state and snapshot image">
  <Workflow Limit="1" Live="1" Timeout="PT10S">
    <Task name="Main" while="true">
      <Event name="Argument" as="ActionArgument"/>
      <Invoke name="GetImage" waitFor="Argument" delay="PT1S" get="[%:[:AA:].URL.Value:%]/cgi-bin/video_snapshot.cgi?[:UP:]"/>
      <Output name="Result" as="ActionResult">
        <Value>
          <State>[%:[%:@Output:%]/if([:IOK:]) then 'ON' else 'OFF':%]</State>
          <Image>[%:[%:@Output:%]/if([:IOK:]) then Invoke/GetImage/Message/Value/text() else '/img/no-image.jpg':%]</Image>
        </Value>
      </Output>
    </Task>
  </Workflow>
</Action>

Rules for Selecting an Action:

TQLEngine Rules for selecting an Action are as follows. Please note that an Action is Triggered whenever there is a change detected between "Value" and "Known" values of a ThingFacet Attribute. A change is notified by Applications using TQL Update Query.

Order of Action Names specified in KnownBy - The first Action Name gets first preference, second gets second preference and so on.
Minimum number of Action (s) that satisfy the update criteria. This rule is used in conjunction with previous order of preference rule.

ESKY Camera Thing Facet

<ThingFacet name="Esky">
  <Sid name="CameraId"/>
  <String name="URL"/>
  <String name="UserName"/>
  <String name="Password"/>
  <String name="State" KnownBy="SyncImageAction,SyncPresetAction"/>
  <String name="Image" KnownBy="SyncImageAction"/>
  <String name="Preset" KnownBy="SyncPresetAction"/>
  <Unique name="Camera" value="URL"/>
  <!-- Helpers -->
  <AA>[:#o#Event.Argument:]</AA>
  <UP>user=[%:[:AA:].UserName.Value:%][%:amp:%]pwd=[%:[:AA:].Password.Value:%]</UP>
  <POK>Invoke/SetPreset/Message/starts-with(Value, 'ok')</POK>
  <IOK>Invoke/GetImage/Message/starts-with(Value, 'data')</IOK>
  <!-- Actions -->
  <Action name="SyncPresetAction" documentation="Synchronize camera state and preset">
    <Workflow Limit="1" Live="1" Timeout="PT20S">
      <Task name="Main" while="true">
        <Event name="Argument" as="ActionArgument"/>
        <Invoke name="SetPreset" waitFor="Argument" skip-if="[%:[:AA:].Preset/no-value(Value):%]" delayAfter="PT5S"
          get="[%:[:AA:].URL.Value:%]/cgi-bin/decoder_control.cgi?[:UP:][%:amp:%]command=15[%:amp:%]sit=[%:[:AA:].Preset.Value:%]"/>
        <Output name="Result" as="ActionResult">
          <Value>
            <State> [%:[%:@Output:%]/if([:POK:]) then 'ON' else 'OFF':%]</State>
            <Preset>[%:[%:@Output:%]/if([:POK:]) then '[%:[:AA:].Preset.Value:%]' else null():%]</Preset>
          </Value>
        </Output>
      </Task>
    </Workflow>
  </Action>
  <Action name="SyncImageAction" documentation="Synchronize camera state and snapshot image">
    <Workflow Limit="1" Live="1" Timeout="PT10S">
      <Task name="Main" while="true">
        <Event name="Argument" as="ActionArgument"/>
        <Invoke name="GetImage" waitFor="Argument" delay="PT1S" get="[%:[:AA:].URL.Value:%]/cgi-bin/video_snapshot.cgi?[:UP:]"/>
        <Output name="Result" as="ActionResult">
          <Value>
            <State>[%:[%:@Output:%]/if([:IOK:]) then 'ON' else 'OFF':%]</State>
            <Image>[%:[%:@Output:%]/if([:IOK:]) then Invoke/GetImage/Message/Value/text() else '/img/no-image.jpg':%]</Image>
          </Value>
        </Output>
      </Task>
    </Workflow>
  </Action>
</ThingFacet>

For example in case of ESKY Camera Facet - here is the list the table of Attribute, Action Association and Attributes that get affected by Actions.

Attribute	Action(s) Association	Attribute(s) Being Updated By Action
State	SyncImageAction, SyncPresetAction	State, Image, Preset
Image	SyncImageAction	State, Image
Preset	SyncPresetAction	State, Preset

Based on the above Action Association and Rules applied by the TQLEngine, table below gives possibilities:

User's (Applications) Desire to update using TQL Update Query	Action Selected by TQLEngine
Image	SyncImageAction
Preset	SyncPresetAction
Image, State	SyncImageAction
State	SyncImageAction (* Note both Rules get applied)