How to pass a variable through a service call within the data field in node-red?

Third party integrations Node-RED
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How do I pass a variable within Node-Red? Either from a system variable/state, or from a msg.payload? I swear I’ve done this before but I’ve only passed it directly to an iOS notification which works differently.

See my example below

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I use myself a function node in front of the service call (see example below). However, maybe there is a better way by using templates or somthing like that and avoiding the function node… I would be happy to learn a better way !

This is what I’m currently doing:
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In the function node I’ve put:

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And then for the service call:
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2 Likes
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You can use "/config/www/{{time}}..." in your template. The sidebar docs in Node Red say:

You can use templates in the Domain , Service , Entity Id , and data fields. When using templates the top level is a property of the message object: msg.payload would be {{payload}} . You can also access the flow, global and states contexts {{flow.foobar}} {{global.something}} . For the states context you can use the {{entity.domain.entity_id}} to just get the state or drill further down like {{entity.light.kitchen.attributes.friendly_name}} . {{entity.light.kitchen}} and {{entity.light.kitchen.state}} are equivalent.

So you just needed to drop the msg. part and I think you are good.

4 Likes
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Wow, this is fantastic !

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Ok that worked perfect thank you @Frixx @knobunc

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Note that while you can print state (which is quite cool), there’s no conditional stuff in the mustache templates.

I had to use a ‘template’ node to make a template with the node red variables that I pass to a ‘get template’ node for home assistant to process and the result is the message I send. A bit ugly, but it works well.

The ‘template’ node’s template is:

{{=<% %>=}}
{{ state_attr("<% topic %>", 'friendly_name') }} 
{%- if "<% payload %>" == "home" %} arrived home {%- else %} has left the house{%- endif %}.

(The first line changes the delimiters of mustache to <% %> so I can easily use {{ }} for home assistant templates).

So that generates a home assistant template that get template then passes through home assistant to process.

-ben

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Interesting. I’ve run into an error however.

I have a service call node that needs to replace the data for a media_player entity with a value for volume stored in a flow variable. The location of the data is at flow.mediaPlayer.kitchen.volume_snapshot.

If I add

{"volume_level","{{flow.mediaPlayer.kitchen.volume_snapshot}}"}

to the DATA field, I get a "Call-service API error. Error Message: extra keys not allowed @ data['0']" in my debug node.

I could easily alter the msg.payload to contain this information and just use {{payload}} in the data field, but I’m trying to learn this method and reduce the number of nodes I’m using.

Possible?

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Try this, you were missing the colons

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Lol…I just figured that out when you responded.

1 Like