I do agree with the answer posted by @tatsuDn but I wanted to provide a solution that loads your environment variables from a .env file.
First create a .env file in the root folder of your project.
Ensure that you add the file to your pubspec.yaml and [git] ignore it.
Here is how your .env file should look
API_KEY=sampleapikey
# This line is a comment
# The white line above will be ignored
HEADER=sampleapiheader
ANOTHER_UNIQUE_KEY=theValueOfThisKey
KEY_CONTAINS_#=*234*5#
KEY_CONTAINS_EQUALS=IP8iwe=0&
Here is how your assets section to look like.
# To add assets to your application, add an assets section, like this:
assets:
- assets/images/
- assets/flags/
- .env
Finally, load your environment variable by reading and parsing the .env file to get a Map<String, String> that contains your key value pairs.
Future<Map<String, String>> parseStringToMap({String assetsFileName = '.env'}) async {
final lines = await rootBundle.loadString(assetsFileName);
Map<String, String> environment = {};
for (String line in lines.split('\n')) {
line = line.trim();
if (line.contains('=') //Set Key Value Pairs on lines separated by =
&&
!line.startsWith(RegExp(r'=|#'))) {
//No need to add emty keys and remove comments
List<String> contents = line.split('=');
environment[contents[0]] = contents.sublist(1).join('=');
}
}
return environment;
}
You can put a quick button in your code to test that the environment variables are being loaded properly.
ElevatedButton(
onPressed: () async {
final env = await parseStringToMap(assetsFileName: '.env');
print(env);
},
child: Text('Print Environment Variables')
),
Here is the output from the .env file above.
>>>I/flutter ( 7182): {API_KEY: sampleapikey, HEADER: sampleapiheader, ANOTHER_UNIQUE_KEY: theValueOfThisKey, KEY_CONTAINS_#: *234*5#, KEY_CONTAINS_EQUALS: IP8iwe=0&}
Notes: You will need to rerun the app (not hot reload) so that the .env assets is loaded.
You can also just load your variables in a json file[this may be helpful when you have non string environemental variables and you dont want to parse string.
To avaoid IO, it is a good Idea to just load the environment variables once and access them through out the app using service locators like GetIt.
