IO Actions: Block Reference

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Block: Join Text ​

Type: io_text_join

the Join Text block

Join two pieces of text into one combined string. Perfect for building dynamic messages, creating formatted outputs, or combining data from different sources into readable text.

What is Join Text? ​

Think of Join Text like using a plus sign (+) to glue two pieces of text together. Just like "Hello" + "World" becomes "HelloWorld", this block combines any two text values into one.

How It Works ​

INFO

Input A + Input B → Combined Output

Example: "Hello " + "World" → "Hello World"

The Join Text block takes two inputs (A and B) and combines them into a single text output:

  • Input A: First piece of text
  • Input B: Second piece of text
  • Output: A + B (combined text)

Important!

The texts are joined directly with no space between them. If you want a space, you need to add it yourself!

Basic Examples ​

Simple Text Joining ​

Input AInput BOutput
"Hello""World""HelloWorld"
"Hello ""World""Hello World"
"Temperature: ""72°F""Temperature: 72°F"

Adding Spaces and Punctuation ​

Input AInput BOutput
"Good"" morning!""Good morning!"
"Status:"" Active""Status: Active"
"User""#1234""User#1234"

IoT Use Cases ​

🏷️ Creating Labels with Values ​

Temperature Label:

js
A: "Kitchen Temp: "
B: {{ feeds['sensors.kitchen_temp'].value }}
// Output: "Kitchen Temp: 72.5"

Device Status:

js
A: "Door is "
B: {{ feeds['security.door'].value }}
// Output: "Door is OPEN" or "Door is CLOSED"

📊 Building Status Messages ​

Battery Level:

js
A: "Battery at "
B: {{ vars.battery_percent }}%
// Output: "Battery at 85%"

Sensor with Units:

js
A: {{ feeds['sensors.humidity'].value }}
B: "% humidity"
// Output: "65% humidity"

👤 Personalizing Messages ​

Welcome Message:

js
A: "Welcome back, "
B: {{ user.name }}
// Output: "Welcome back, John Smith"

Custom Greeting:

js
A: {{ vars.greeting }}
B: {{ user.username }}
// Output: "Hello, jsmith123"

🔗 Creating URLs and Paths ​

js
A: "https://api.example.com/sensors/"
B: {{ vars.sensor_id }}
// Output: "https://api.example.com/sensors/temp_01"
js
A: "/data/"
B: {{ vars.filename }}
// Output: "/data/readings_2024.csv"

🎨 Formatting with Symbols ​

js
// Arrow Indicators
A: "Temperature "
B: "↑ Rising"
// Output: "Temperature ↑ Rising"

// Status Icons
A: "🔋 "
B: {{ vars.battery_status }}
// Output: "🔋 Charging" or "🔋 Full"

Advanced Patterns ​

Chaining Multiple Join Blocks

Sometimes you need to combine more than two pieces of text. Use multiple Join Text blocks:

Three-Part Message:

js
// First Join
A: "Hello, "
B: {{ user.name }}
// Result: "Hello, John"

// Second Join (using first result)
A: [First Join Output]
B: "! Welcome back."
// Final Output: "Hello, John! Welcome back."
Building Complex Messages

Multi-Line Status Report (using \n for line breaks):

js
// First Join
A: "System Status\n"
B: "Temperature: OK\n"

// Second Join
A: [First Join]
B: "Humidity: OK\n"

// Third Join
A: [Second Join]
B: "Battery: Low"

/* Output:
System Status
Temperature: OK
Humidity: OK
Battery: Low
*/
Conditional Text Building

Combine with logic blocks to build different messages:

js
A: "Sensor "
B: [If temperature > 80 then "⚠️ HOT" else "✓ Normal"]
// Output: "Sensor ⚠️ HOT" or "Sensor ✓ Normal"

Common Patterns & Tips ​

1. Don't Forget Spaces!

Common Mistake

Forgetting to add spaces is the #1 beginner error!

Wrong:

js
A: "Hello"
B: "World"
// Output: "HelloWorld" ❌

Right:

js
A: "Hello "  // Space at the end
B: "World"
// Output: "Hello World" ✅

Also Right:

js
A: "Hello"
B: " World"  // Space at the beginning
// Output: "Hello World" ✅
2. Adding Separators
SeparatorInput AInput BOutput
Comma{{ vars.city }}", USA""Boston, USA"
Dash{{ vars.date }}" - Event""2024-01-15 - Event"
Colon"Error"": Connection lost""Error: Connection lost"
3. Building Lists
js
// Bullet Point
A: "• "
B: {{ vars.item_name }}
// Output: "• Temperature Sensor"

// Numbered
A: "1. "
B: {{ vars.first_step }}
// Output: "1. Check connections"
4. Combining Numbers and Text

When joining numbers with text, the number is automatically converted:

js
A: "Count: "
B: {{ vars.sensor_count }}
// Output: "Count: 5"

A: {{ feeds['sensor'].value }}
B: " degrees"
// Output: "72.5 degrees"
5. Empty String Handling

If one input is empty, you get just the other input:

js
A: "Hello"
B: ""
// Output: "Hello"

A: ""
B: "World"
// Output: "World"

Working with Other Blocks ​

Join + Text Template

Use Join Text to prepare strings for templates:

js
// Join to create feed key
A: "sensor."
B: {{ vars.location }}
// Output: "sensor.kitchen"

// Then use in template
{{ feeds['[Join Output]'].value }}
Join + Variables

Store joined text in a variable for reuse:

js
// Join
A: "Alert: "
B: {{ vars.message }}

// Store result in variable: "formatted_alert"
// Use later in multiple places
Join + Conditionals

Build different messages based on conditions:

js
A: "Status: "
B: [If block result]
// Where If block returns "Online" or "Offline"
// Output: "Status: Online" or "Status: Offline"

Troubleshooting ​

Problem: Text runs together without spaces

Solution: Add a space at the end of the first text or beginning of the second text:

  • Change "Hello" to "Hello "
  • Or change "World" to " World"
Problem: Getting [object Object] in output

Solution: Make sure you're passing text/string values, not complex objects. Use the .value or .name property of feeds:

  • Wrong: B: {{ feeds['sensor.temp'] }}
  • Right: B: {{ feeds['sensor.temp'].value }}
Problem: Numbers not displaying correctly

Solution: Numbers are automatically converted to text. For formatting, use a Text Template block first:

  • Basic: A: "Price: $" B: {{ vars.price }} → "Price: $9.99"
  • Formatted: Use template with {{ vars.price | round: 2 }} first
Problem: Special characters not showing

Solution: Use Unicode or HTML entities:

  • Degree symbol: Use "°" or "°"
  • Line break: Use "\n"
  • Tab: Use "\t"

Quick Reference ​

Task Reference Table
TaskInput AInput BOutput
Add label"Temp: ""72°F""Temp: 72°F"
Add units"50""%""50%"
Add prefix"Error: "message"Error: [message]"
Add suffixfilename".txt""[filename].txt"
Join namesfirst_namelast_name"[first][last]" (no space!)
With spacefirst_name + " "last_name"[first] [last]"
Line break"Line 1\n""Line 2"Two lines
Build path"/home/"username"/home/[username]"
When to Use Join Text vs Text Template

Use Join Text when:

  • Combining exactly two pieces of text
  • Simple concatenation without complex formatting
  • Building URLs, paths, or IDs
  • Adding prefixes or suffixes

Use Text Template when:

  • Combining more than two pieces of text
  • Need advanced formatting (dates, numbers)
  • Using conditional logic
  • Creating multi-line messages
  • Need more control over output format

Inputs ​

A ​

The first string of text - this will appear first in the combined output. Can be static text like 'Hello' or dynamic data from feeds/variables. Don't forget to add a space at the end if you want separation from the second text!

Compatible Blocks (click to expand)
the Get Variable block

Get Variable

Retrieve the value stored in a variable that was previously set using a Set Variable block.

the Multiline Text block

Multiline Text

Create formatted text content with multiple lines, paragraphs, and line breaks.

the Text block

Text

Enter any text content for use in your Actions - words, phrases, device commands, or messages.

the Text Template block

Text Template

Create dynamic, personalized messages by combining static text with live data from your IoT system.

the Join Text block

Join Text

Join two pieces of text into one combined string.

the Text Compare block

Text Compare

Compare two text values using different comparison operations.

the Weather block

Weather

Fetch the current or forecast weather conditions at the specified location.

the Air Quality block

Air Quality

Fetch current or forecast air quality conditions at the specified location using Open-Meteo Air Quality API.

the Round/Floor/Ceiling block

Round/Floor/Ceiling

Convert decimal numbers to whole numbers using different rounding strategies.

the Number block

Number

Enter any numerical value for use in your IoT Actions - whole numbers, decimals, positive, or negative.

the Map block

Map

Transform sensor readings and data values by scaling them from one number range to another.

the Constrain block

Constrain

Keep any number within specified minimum and maximum boundaries.

the Compare Numbers block

Compare Numbers

Build mathematical conditions by comparing any two numerical values in your Action logic.

the Arithmetic block

Arithmetic

Perform mathematical calculations using sensor data, feed values, or any numbers in your Actions.

the Logic Operation block

Logic Operation

Combine multiple conditions to create sophisticated decision logic in your Actions.

the Negate block

Negate

Flip any condition to its opposite - turns true into false and false into true.

the Boolean block

Boolean

A simple true or false value for building logic conditions and controlling digital outputs.

the Get Feed Value block

Get Feed Value

Resolves to the last value of this feed or component, always a String.

the JSONPath Query block

JSONPath Query

Extract specific values from JSON data using JSONPath query syntax.

B ​

The second string of text - this will appear immediately after the first text with no automatic spacing. Can be static text or dynamic values. Add a space at the beginning if you need separation from the first text.

Compatible Blocks (click to expand)
the Get Variable block

Get Variable

Retrieve the value stored in a variable that was previously set using a Set Variable block.

the Multiline Text block

Multiline Text

Create formatted text content with multiple lines, paragraphs, and line breaks.

the Text block

Text

Enter any text content for use in your Actions - words, phrases, device commands, or messages.

the Text Template block

Text Template

Create dynamic, personalized messages by combining static text with live data from your IoT system.

the Join Text block

Join Text

Join two pieces of text into one combined string.

the Text Compare block

Text Compare

Compare two text values using different comparison operations.

the Weather block

Weather

Fetch the current or forecast weather conditions at the specified location.

the Air Quality block

Air Quality

Fetch current or forecast air quality conditions at the specified location using Open-Meteo Air Quality API.

the Round/Floor/Ceiling block

Round/Floor/Ceiling

Convert decimal numbers to whole numbers using different rounding strategies.

the Number block

Number

Enter any numerical value for use in your IoT Actions - whole numbers, decimals, positive, or negative.

the Map block

Map

Transform sensor readings and data values by scaling them from one number range to another.

the Constrain block

Constrain

Keep any number within specified minimum and maximum boundaries.

the Compare Numbers block

Compare Numbers

Build mathematical conditions by comparing any two numerical values in your Action logic.

the Arithmetic block

Arithmetic

Perform mathematical calculations using sensor data, feed values, or any numbers in your Actions.

the Logic Operation block

Logic Operation

Combine multiple conditions to create sophisticated decision logic in your Actions.

the Negate block

Negate

Flip any condition to its opposite - turns true into false and false into true.

the Boolean block

Boolean

A simple true or false value for building logic conditions and controlling digital outputs.

the Get Feed Value block

Get Feed Value

Resolves to the last value of this feed or component, always a String.

the JSONPath Query block

JSONPath Query

Extract specific values from JSON data using JSONPath query syntax.