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# Injecting a variable into text: double curly braces

# 🧩 Injecting a variable into text: double curly braces

The mechanism fits in one sentence: **any word written between double curly braces in a text field makes a new input point appear on the block.** You punch a hole in your sentence, and Celestory builds the socket that will fill it. 🪄

---

## ✍️ The principle in three steps

In a Dialogue block, you type:

```plain text
Hello {{FirstName}}! You have {{Score}} points.
```

1. **You write.** Two inputs appear on the block: `FirstName` and `Score`.
1. **You connect.** They are points like any other: plug in a variable, another block's output, or type a hard-coded value.
1. **Celestory substitutes.** At runtime, each reference gives way to the value it received.

🔺 **A single curly brace triggers nothing.** `{FirstName}` will be displayed as is, literally.

🔺 **Creating the point is not enough, you have to wire it.** An input left dangling is replaced by **nothing at all**: your sentence becomes "Hello ! You have  points.", without the slightest error message.

---

## 🔤 What you are allowed to write between the braces

The name only accepts **unaccented letters**, **digits** and the **underscore** `_`. Everything else breaks detection **silently**: no input is created.

```plain text
{{FirstName}}     ✅ detected
{{Score_2}}       ✅ detected
{{Café}}          ❌ the accent breaks everything
{{my-score}}      ❌ the hyphen is not accepted
{{ FirstName }}   ❌ nor are the spaces
```

🔺 No, you **cannot** write `{{Café}}`. Put your accents in the rest of the sentence, never inside the braces.

🔺 Case matters: `{{Score}}` and `{{score}}` create **two different inputs**.

---

## 🔁 The same variable quoted several times

```plain text
Well played {{FirstName}}! Really, {{FirstName}}, what a game.
```

Celestory creates **only one point**, `FirstName`, not two. You wire it once, and **every** occurrence is replaced. ✅

---

## 🎚️ What type is the point that gets created?

The point is not locked to "Text". It accepts **Text**, a **Number** or a **Boolean** interchangeably, and the value is converted to text when displayed.

Two blocks also accept an **Object**: **Format text** and the **Dialogue** block of the Chatbot template. The object is inserted there in its raw form — useful for debugging, rarely elegant for a player.

---

## 🧱 The blocks concerned

The mechanism is not universal: it lives in ten blocks.

**Whatever the template:** **Format text** (the dedicated block, which does nothing else and returns the assembled text), **Notification**, and **HTML5** — where the braces go in the code, not in a text field.

**Chatbot template:** **Dialogue**, **Choice with dialogue**, **Narrator**, **Alert**.

**Visual Novel template:** **Dialogue**, **Alert**, **Slide**.

🔺 Everywhere else, `{{...}}` is nothing but ordinary text. Need a dynamic sentence in another block? Build it with **Format text** and wire its output wherever it is needed.

---

## ⚠️ Renaming a reference means losing its wire

A point is only recognised by its exact name. If you correct `{{FirstName}}` to `{{PlayerFirstName}}`, Celestory considers that the old point no longer exists: **it deletes it, and deletes the link that was plugged into it.** The new point appears blank. Likewise, removing `{{Score}}` from the sentence makes the `Score` input disappear.

So check your connections after every text tweak, especially on a block that holds five or six references.

---

→ Next step: open a **Format text** block, write `Hello {{FirstName}}, you have {{Score}} points.`, connect the two inputs to your variables and wire the output into a Dialogue block. You are holding the basic building block of all personalisation in Celestory.