How to Use the Format Editor

StringLane supports four file formats and adjusts its editing behavior for each one. The format is detected automatically from your project files — no configuration required.

Supported formats

Format	File type	Used in
Flutter ARB	app_*.arb (JSON)	Flutter, Dart
iOS Strings	Localizable.strings	iOS, macOS (UIKit/AppKit)
Android XML	res/values*/strings.xml	Android
i18next JSON	*.json in locale folders	React, Node.js, web apps

Flutter ARB

ARB (Application Resource Bundle) is a JSON format with a specific structure. StringLane:

• Reads and writes the @key metadata objects (@description, x-max-length, x-guarded) without touching them
• Preserves key order exactly as it appears in the source file
• Handles ICU MessageFormat strings in values (see Working with ICU Plurals)
• Shows {placeholder} names as Param badges when they're mismatched between locales

See How to Work with ARB Metadata Annotations for details on the @key system.

iOS .strings

Standard iOS .strings format uses "key" = "value"; pairs, one per line. StringLane:

• Preserves all /* comment */ blocks above each key — they're not editable in StringLane but are passed through intact
• Reads .lproj-based locale structure (en.lproj/, fr.lproj/, etc.)
• Handles format specifiers like %@, %d, %1$@ — mismatches between locales are flagged as Param badges
• Does not support .stringsdict (plural files) directly — these are distinct files; work on them in the ARB view if your project uses a dual system

Android XML

Android resources use <string> tags in res/values/strings.xml. StringLane:

• Reads all <string name="...">value</string> entries
• Handles <plurals> elements as multi-value entries, one per quantity (zero, one, two, few, many, other)
• Preserves <![CDATA[...]]> wrappers and XML special characters (&, <, etc.)
• Maps locale variants to values-fr/, values-de/, etc.
• Format specifiers (%s, %d, %1$s) are treated like ARB placeholders for Param validation

i18next JSON

i18next uses JSON files with locale code as the folder name (en/translation.json, fr/translation.json). StringLane:

• Supports nested key paths using dot notation (e.g. settings.account.title appears as a single row)
• Handles {{variable}} interpolation syntax — mismatches flagged as Param badges
• Preserves key order and nesting structure when writing back to disk
• Does not flatten nested keys — they stay nested

Format detection

If StringLane loads a mixed folder (multiple formats), each format is shown in a separate section or you're prompted to select which to work with. Most projects use a single format throughout.