Questions about Braces Syntax Usage in Mustache Template

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1

Hi all,

I returned three messages in an array from a function. All three messages are returned in JSON format.

The following is the result that I can see in debug:

image
image.png467×604 32.1 KB

How to pass these three messages in mustache template (payload[0], payload[1] and payload[2] separately)?

I aware that payload[0], payload[1] and payload[2] are the values, but I don't think payload[0] syntax will work in mustache template.

I also have another question. For example, I have the following function:

msg.topic="SELECT * FROM location";

var msg1={};
msg1.topic="SELECT * FROM type";

return [msg,msg1];

If I'm passing msg value to mustache template, {{{payload}}} is the syntax.

If I'm passing msg1 value to the mustache template, how is the syntax going to be?

Thanks for helping.

2

Hi,

to access array properties in mustache syntax, you have to use the dot-syntax: payload.0

When you return two messages from a Function with [msg , msg1], then msg will be sent out of the first Function node output and msg1 will be sent out of the second output.

If you return [ [msg, msg1] ] then they will be both sent from the first output, one after the other. That is an important thing to understand - they are sent one after the other. The Template node does not receive both messages at the same time - they arrive as individual messages.

It does not matter what you called the local variable in the Function node, when a message arrives at a Template node its the message. So {{{payload}}} will always refer to the payload property of the message the Template node is currently handling.

3

Hi Nick,

Thanks for the explanation.

I'm using JSGrid to display data and perform CRUD operation. The fields with type "select" (dropdown) are not displaying data. Once I click to add and edit data, I'm unable to make the fields to appear as dropdown with options from the database (e.g. Location_Name from location table). I just would like to make this work.

Here's the link of the topic for more information: Gridview with CRUD Options (MySQL)

I tried the following syntax to access array properties in mustache template, but I'm unable to display the data. Maybe the syntax is incorrect.

var db = {{{payload.0}}}; //payload[0] (Data for main)
var loc = {{{payload.1}}}; //payload[1] (Data for dropdown 1)
var mac = {{{payload.2}}} //payload[2] (Data for dropdown 2)

{
	title: "Location",
	name: "location",
	type: "select",
	items: loc,
	width: 100
}

{
	title: "Type",
	name: "type",
	type: "select",
	items: mac,
	width: 100
}

Hope to hear from you soon. Thanks for helping.