Custom Text Formatter - CometChat Docs

Goal

By the end of this guide you will have a color button in the composer’s rich-text toolbar. The user selects some text, taps a swatch, and the text turns that color — in the composer while typing, and in the message bubble after it is sent. In React Native you do not need to write a text formatter for this. Text color is part of the UI Kit’s built-in rich-text format, so the work splits into two small pieces:

Authoring — a button in the composer’s ToolbarTrailingButtonsView slot that applies a color to the current selection through the composer handle.
Rendering — nothing to do. The UI Kit already renders colored text wherever it formats rich text.

This guide colors text with the built-in rich-text format. To build your own inline pattern — hashtags, keywords, custom tokens — see the Text Formatter Base Class guide instead.

Prerequisites

Completed the Integration Guide
A chat screen using CometChatMessageList and CometChatCompactMessageComposer

ToolbarTrailingButtonsView exists on CometChatCompactMessageComposer only. CometChatMessageComposer has no formatting toolbar, so there is nowhere to mount the button.

ToolbarTrailingButtonsView renders your views at the end of the formatting toolbar, after a divider. It is a render function, and besides user, group and composerId it receives a composer handle — the same controls the built-in Bold and Italic buttons use. The toolbar shows an A and a ✕. Tapping A swaps them for a row of color swatches; tapping a swatch colors the selection. ✕ removes the color from the selection. File: ChatScreen.tsx

import React, { useState } from "react";
import { Text, TouchableOpacity, View } from "react-native";
import {
  CometChatCompactMessageComposer,
  CometChatMessageList,
  useTheme,
} from "@cometchat/chat-uikit-react-native";

const SWATCHES = ["#E11D48", "#F59E0B", "#10B981", "#3B82F6", "#8B5CF6"];

function ChatScreen({ user, group }) {
  const theme = useTheme();
  // Keep the open/closed state in the screen, not inside the render function — see the note below.
  const [colorPickerOpen, setColorPickerOpen] = useState(false);

  return (
    <>
      <CometChatMessageList user={user} group={group} />

      <CometChatCompactMessageComposer
        user={user}
        group={group}
        ToolbarTrailingButtonsView={({ composer }) =>
          colorPickerOpen ? (
            <>
              {SWATCHES.map((swatch) => (
                <TouchableOpacity
                  key={swatch}
                  accessibilityLabel={`Color ${swatch}`}
                  style={{ paddingHorizontal: 5, paddingVertical: 4 }}
                  onPress={() => {
                    composer.applyInlineStyle("color", swatch);
                    setColorPickerOpen(false);
                  }}>
                  <View
                    style={{ width: 18, height: 18, borderRadius: 9, backgroundColor: swatch }}
                  />
                </TouchableOpacity>
              ))}
              <TouchableOpacity
                accessibilityLabel="Close colors"
                style={{ paddingHorizontal: 8, paddingVertical: 4 }}
                onPress={() => setColorPickerOpen(false)}>
                <Text style={{ color: theme.color.iconSecondary }}>✕</Text>
              </TouchableOpacity>
            </>
          ) : (
            <>
              {/* Disabled inside a code block: send keeps code blocks as raw text and
                  drops inline styles, so a color applied there would vanish on send. */}
              <TouchableOpacity
                accessibilityLabel="Color selected text"
                disabled={composer.getActiveStyles().codeBlock}
                style={{
                  paddingHorizontal: 8,
                  paddingVertical: 4,
                  opacity: composer.getActiveStyles().codeBlock ? 0.4 : 1,
                }}
                onPress={() => setColorPickerOpen(true)}>
                <Text style={{ color: "#E11D48", fontWeight: "700" }}>A</Text>
              </TouchableOpacity>
              <TouchableOpacity
                accessibilityLabel="Remove text color"
                style={{ paddingHorizontal: 8, paddingVertical: 4 }}
                onPress={() => composer.removeInlineStyle("color")}>
                <Text style={{ color: theme.color.iconSecondary }}>✕</Text>
              </TouchableOpacity>
            </>
          )
        }
      />
    </>
  );
}

Keep the picker’s state in your screen. The composer mounts ToolbarTrailingButtonsView as a component, and an inline render function is a new function every time your screen re-renders, so whatever it returns is remounted. State held inside it — an open flag in a child component, for example — resets, and the picker closes on its own.

Keep the swatches inside the toolbar — do not open a Modal. A modal takes focus from the text input, which collapses the selection before applyInlineStyle runs, so nothing gets colored. Views rendered inline in the toolbar keep the selection alive, the same way the built-in buttons do.

Step 2: Try It

The slot lives inside the formatting toolbar, so it only renders while the toolbar is visible: enableRichTextEditor must be true and hideRichTextFormattingOptions must be false. Both are the defaults, so the screen above needs neither. The user selects “world”, taps A, picks red, and the word turns red in the composer. With no selection, the color applies to whatever they type next, the same way Bold does. On send, the message text becomes Hello <color=#e11d48>world</color>.

Step 3: Where the Color Shows Up

There is nothing to register. The UI Kit’s rich-text formatting reads the color markup and renders it as colored text on the surfaces that format message text, including:

Message bubbles in CometChatMessageList — and therefore in threads and in CometChatPinnedMessages, which render the same bubbles
The last-message subtitle in CometChatConversations
Results in CometChatSearch

Unlike the React UI Kit, you do not add a formatter to each surface — the color is not a custom marker, so every UI Kit surface that renders rich text already understands it.

What Gets Sent

In the composer	Sent as	Why
Any React Native color string: `'#E11D48'`, `'red'`, `'rgb(225, 29, 72)'`	`<color=#rrggbb>…</color>`	The editor normalises the color, and the message always carries a 6-digit hex
A transparent color, e.g. `'rgba(225, 29, 72, 0.5)'`	Sent fully opaque	The alpha channel is dropped, so text can never be sent invisible
`applyInlineStyle("backgroundColor", …)`	Nothing	Background color only styles the composer; it is not part of the message format, so it is dropped on send
Color inside a code block	Nothing	Code blocks are sent as raw text with every inline style removed
A selection that contains a mention	Mention left uncolored	`applyInlineStyle` skips mentions so they keep their own styling

Use "color" for anything the recipient should see. "backgroundColor" is accepted by applyInlineStyle but never leaves the device.

How It Round-Trips

Composer (author)         Wire format                   Bubble (reader)
─────────────────         ───────────                   ───────────────
select "world"            Hello <color=#e11d48>         Hello world
tap A → red         →      world</color>          →     (in red, built in)

The markup is plain text on the message, so it survives storage and delivery untouched. Every UI Kit surface that renders rich text turns it back into color on its own.

The `composer` Handle

The handle your button receives. Every method acts on the live composer input.

Method	Description
`getText()`	Current plain-text content
`getSelection()`	Current selection as `{ start, end }` — collapsed when there is only a caret
`setText(text)`	Replaces the content
`setSelection(start, end?)`	Moves the selection; omit `end` for a caret
`insertLink(url, text)`	Inserts a link, wrapping the selection when there is one
`toggleBold()` / `toggleItalic()` / `toggleUnderline()` / `toggleStrikethrough()` / `toggleCode()`	Same as the built-in toolbar buttons
`clearFormatting()`	Removes all inline formatting from the selection
`applyInlineStyle(key, value)`	Applies `"color"` or `"backgroundColor"` to the selection
`removeInlineStyle(key)`	Removes that style from the selection
`getMentionRanges()`	Mention ranges in plain-text positions
`getActiveStyles()`	Formatting at the caret — `bold`, `italic`, `underline`, `strikethrough`, `code`, `codeBlock`, `highlight`, `blockType`, `alignment`

getActiveStyles() does not report the current color, so a color button cannot show which swatch is active.

Next Steps

Compact Message Composer → ToolbarTrailingButtonsView — the toolbar slot in detail
Text Formatter Base Class — build your own inline patterns with CometChatTextFormatter
Message List — where the colored message renders

​Goal

​Prerequisites

​Step 1: The Toolbar Button

​Step 2: Try It

​Step 3: Where the Color Shows Up

​What Gets Sent

​How It Round-Trips

​The composer Handle

​Next Steps

Goal

Prerequisites

Step 1: The Toolbar Button

Step 2: Try It

Step 3: Where the Color Shows Up

What Gets Sent

How It Round-Trips

The `composer` Handle

Next Steps