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if

Conditional routing — evaluate fields against operators and values to branch message flows.

Overview

The if node evaluates a condition against message data and routes messages to one of two outputs: a true branch or a false branch. It inspects a specified field using a comparison operator and value, making it the primary building block for decision logic in any EdgeFlow pipeline.

8
Operators
2
Output Branches
Nested
Field Access
Dynamic
Value Types

Properties

Property Type Default Description
field string "payload" Dot-notation path to the field to evaluate (e.g. "payload.temperature")
operator string "eq" Comparison operator: eq, ne, gt, lt, gte, lte, contains, exists
value any — Value to compare the field against (ignored for "exists")
condition string — Optional raw expression string evaluated as a JavaScript expression
_condition_result boolean — Appended to msg.payload with the evaluation result (true/false)
_branch string — Appended to msg.payload — "true" or "false" indicating selected branch

Operators

eq / ne

Equal / Not Equal — strict comparison

field: "payload.status"
operator: "eq"
value: "active"
// true when status === "active"

gt / lt / gte / lte

Numeric comparisons — greater/less than

field: "payload.temperature"
operator: "gt"
value: 30
// true when temperature > 30

contains

Substring match on string fields

field: "payload.message"
operator: "contains"
value: "error"
// true when message includes "error"

exists

Check if a field is present and not undefined

field: "payload.gps"
operator: "exists"
// true when msg.payload.gps is defined
// value property is ignored

Example: Temperature Threshold Routing

Route sensor data based on a temperature threshold — readings above 30 °C trigger an alert, all others are logged normally.

// If node configuration
{
  "field": "payload.temperature",
  "operator": "gt",
  "value": 30
}

// Incoming message
{
  "topic": "sensors/greenhouse",
  "payload": {
    "temperature": 34.5,
    "humidity": 72
  }
}

// Result: _condition_result = true, _branch = "true"
// Message routed to output 1 → Alert node
// If temperature were 28.0 → output 2 → Log node

Example: String Matching for Error Handling

Detect error messages in log streams and route them to a dedicated error handler.

// If node configuration
{
  "field": "payload.message",
  "operator": "contains",
  "value": "error"
}

// Incoming log message
{
  "topic": "app/logs",
  "payload": {
    "level": "warn",
    "message": "Connection error: ETIMEDOUT on port 5432",
    "timestamp": "2025-06-15T08:30:00Z"
  }
}

// Result: _condition_result = true, _branch = "true"
// Routed to error handler → sends Slack notification
// Messages without "error" pass to standard log storage

Example: Optional Field Existence Check

Only process GPS-enabled messages that include location data.

// If node configuration
{
  "field": "payload.gps",
  "operator": "exists"
}

// Message WITH GPS
{
  "payload": {
    "device": "tracker-01",
    "gps": { "lat": 51.5074, "lon": -0.1278 }
  }
}
// → true branch → store in location database

// Message WITHOUT GPS
{
  "payload": {
    "device": "sensor-04",
    "temperature": 22.1
  }
}
// → false branch → skip geolocation processing

Common Use Cases

Threshold Alerts

Trigger alarms when sensor values exceed safe limits

Error Routing

Separate error messages from normal log streams

Feature Flags

Enable or disable downstream paths based on config values

Data Validation

Check for required fields before processing messages

Related Nodes

switch

Multi-branch routing
function

Custom logic evaluation
change

Set/change message properties