r_resources

Description:

r resources

r_resources #




This package is made for R-file code generation using build_runner.
R file contains static access to application asset names and inherited access (via BuildContext) to localized String resources.
With this approach you will not be able to make a typo in any resource name.
How to use #
To use the resources code generation add dev dependency in your pubspec.yaml:
dev_dependencies:
build_runner: <build_runner version here>
r_resources: ^1.0.2
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To generate R-file, run build_runner: flutter pub run build_runner build. r.dart file will be created in lib folder
Plain images and SVG #
In order to generate R-names for image assets, you need to follow these steps:

Create assets folder in project root folder (your_app/assets)
Create images folder for plain image files (such as .png, .jpg, etc.). And/Or create svg folder for .svg files.
Add image assets to these folders.
Add assets to pubspec.yaml:

flutter:
assets:
- assets/images/
- assets/svg/
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Run code generation

Note: to add plain images for different scale factors you may add scaled folders inside images folder.
your_app:
assets:
images:
2.0x:
img.png
3.0x:
img.png
img.png
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After r.dart is generated, you can reference assets like follows:
Image.asset(R.images.ic_individual_schools);
SvgPicture.asset(R.svg.ic_filter);
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Configuration file #
r_resources provides some configuration to code gen.
Add the r_options.yaml config file to project root folder. Example:
path: 'lib/codegen'

generate_strings: true

supported_locales:
- en_US
- en_GB
- ru

fallback_locale: en_US
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Parameters:
path - parameter describing where r.dart would be saved. Path should always start with lib folder. Equals lib by default.
generate_strings - parameter that turns on and off string resources generation. Equals false by default, since you may use other localized strings gen packages.
supported_locales - parameter describing which locales will be supported by your app. Equals en by default. It is only makes sence to add this parameter when generate_strings is true otherwise it will be ignored.
fallback_locale - parameter describing which locale translations will be used in case of missing translations. Equals en by default. It is only makes sence to add this parameter when generate_strings is true otherwise it will be ignored.
Strings #
r_resources provides a simple way to generate string translations to your app.
This generation is turned off dy default.
How to use Strings gen #
To start generating localized strings resources you should set generate_strings parameter to true in configuration file.
Also you may need to configure supported_locales and fallback_locale parameters.
All locale naming used by codegen is using the following format: <language_code>_<country_code>. country_code may be ommited to use generic language code for all nested countries. Examples: en_GB, ru, en. Note that en_GB is not the same as en.
After you configured generate_strings, supported_locales and fallback_locale parameters, you should add translation files to your_app/assets/strings.
In case you specified r_options.yaml like this:
generate_strings: true

supported_locales:
- en_US
- en_GB
- ru

fallback_locale: en_US
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then you should add en_US.json, en_GB.json and en_US.json files. And you need to make sure that en_US.json file contains all possible translations, since it will be used as a fallback.
Translations files are single json-s. Field names in different tranlstion files should match.
en_US.json (fallback locale):
{
"label_lorem_ipsum": "Lorem ipsum",
"label_color": "Color",
"format_example": "Your object is ${object} and other is ${other}",
"label_with_newline": "HELLO!\nI'm new line symbol (\\n)"
}
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ru.json:
{
"label_color": "Цвет",
"format_example": "Ты передал object = ${object}"
}
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With these files have been used to generate R, you can access localized values in code as follows:
Text(R.stringsOf(context).label_lorem_ipsum);
Text(R.stringsOf(context).label_color);
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After successfull code generation r.dart will have 2 new classes:

_Strings which instance can be accesed by R.stringsOf(context) and used as localized values container
RStringsDelegate - the LocalizationsDelegate for type _Strings

You should use RStringsDelegate to configure localizations of your app widget:
return MaterialApp(
...,
supportedLocales: RStringsDelegate.supportedLocales,
localizationsDelegates: [
RStringsDelegate(),
GlobalMaterialLocalizations.delegate,
GlobalWidgetsLocalizations.delegate,
GlobalCupertinoLocalizations.delegate,
],
...,
);
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Formatting #
This package is also supports localized formatting:
en_US.json (fallback locale):
{
"format_example": "Your object is ${object} and other is ${other}"
}
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ru.json:
{
"format_example": "Ты передал object = ${object}"
}
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It looks like string interpolation in json files. After generation you will have the following function instead of getter in _Strings class:
String format_example({
required Object object,
required Object other,
});
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It can be used in code as follows:
Text(
R.stringsOf(context).format_example(
object: 12345,
other: 'OTHER',
),
),
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Planned features #
☑ Plain images
☑ SVG
☑ String resources
☐ Colors
☐ Text styles
☐ Themes
License #
Licensed under the MIT License.