CODEWITHSUNDEEP
dart
Kevin Lee
Kevin Lee

Reputation: 355

Dart : Class Constructor not called

I have following code :

class Article {
    String title;
    String contentString;
    Content content;
    
    Article(String title, String contentString) {
        this.title = title;
        this.content = contentString;
        //I want to call function here
    }

    Article.fromJson(Map<String, dynamic> json)
      : title = json['title'],
        contentString = json['content'];

    void _someFunction() {
       //create function to generate the Content
    }
}

class Content {
  final String text;
  final bool isLink;

  Content({this.text, this.isLink});
}

What i want to achieve is calling a function when the class is initialized. I tried to debug and add break point but it's not triggered. Is it possible to call a function when the class is initialized?

Upvotes: 0

Views: 338

Answers (1)

lrn
lrn

Reputation: 71623

Any code you put at the //I want to... point should be called when the Article constructor is called. It won't be called if the Article.fromJson constructor is called instead. I'm guessing that's what's happening since you haven't said how you constrcut the Articles.

Consider changing the fromJson constructor to:

  Article.fromJson(Map<String, dynamic> json)
      : this(json['title'], json['content']);

This is a redirecting generative constructor, which means it forwards to the Article constructor, and all code run by that will also be run when using Article.fromJson.

Upvotes: 1

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