CODEWITHSUNDEEP
dartyaml
Csteele5
Csteele5

Reputation: 1292

Can't figure out how to load yaml document in Dart

According to the readme for the Dart-Yaml pub package, I should be able to do the following:

var db = loadYamlDocument("db.yaml");

with print(db['hostname']); giving me the value I have specified for port in that yaml, however I'm told that YamlDocument has no instance method []. Okay, I guess that object doesn't have map behaviors, which is something I would have expected it to have. Looking through the docs, there's mention of a YamlMap, but I don't see how to implement that at all.

If I simply try print(db); I actually get the string: 'db.yaml'.

So I tried using new File('db.yaml'); and then sending that variable into the loadYamlDocument method, but that doesn't work either.

Does anyone have any luck reading a yaml document and getting a map out of it in Dart?

Upvotes: 3

Views: 2741

Answers (2)

Hadrien Lejard
Hadrien Lejard

Reputation: 5924

import "dart:io";
import "package:yaml/yaml.dart";

main() {
  File file = new File('pubspec.yaml');
  String yamlString = file.readAsStringSync();
  Map yaml = loadYaml(yamlString);
}

EDIT:

Map loadYamlFileSync(String path) {
  File file = new File(path);
  if (file?.existsSync() == true) {
    return loadYaml(file.readAsStringSync());
  }
  return null;
}

Future<Map> loadYamlFile(String path) async{
  File file = new File(path);
  if ((await file?.exists()) == true) {
    String content = await file.readAsString();
    return loadYaml(content);
  }
  return null;
}

main(List<String> args){
  print(loadYamlFileSync("pubspec.yaml"));
}

Upvotes: 8

Argenti Apparatus
Argenti Apparatus

Reputation: 4013

Check the documentation pages for the Yaml package.

loadYamlDocument() returns a YamlDocument which is a 'heavyweight' class that gives you access to all the features of a Yaml document.

You probably want to use loadYaml, which in most cases is going to return a Map. The description says that the actual implementation of the map is a YamlMap (the Yaml package's implementation of a Map, that they presumably need to use instead of a HashMap for some technical reason).

Upvotes: 3

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