How does the author create meaning in A Doll's House?

The "meaning" of the play, according to the definition of the term "meaning" in literature, would be, in the words of Professor Jon Lye,

In the conventions, traditions, cultural codes which have been handed down, so that. . . the meaning of the text. . . would be created by common traditions and conventions of usage, practice and interpretation.

This being said, meaning has to convey a cultural, traditional, and emotional connection with readers in order for the text to make any sense to them. That is the essential notion of what meaning is. Let us then explore how the playwright uses these three elements to convey connection and thus create "meaning" in the play. 
Culture and conventions connection- The culture to which this refers is the composite of mannerisms, social expectations, and idiosyncrasies of the time and place in which the play occurs. In this case, the "culture" is Victorian society of the mid to late 1800s. The woman is expected to be the proverbial "angel of the household" and social and gender ranks are clearly delineated. 
Ibsen creates meaning when all of these elements are presented well in the play, yet they are endangered by the changes that loom in the horizon: changes that are not just circumscribed to Nora, but to a whole era. These will be times in which women will ask questions, demand an active role in society, and question the "establishment." The pretty little "doll's house," in which Nora is the doll, is slowly coming to a sure and steady end. 
Tradition- Again, the author presents us with visual "stamps" that, for us, are quite easy to relate to: the warming hearth during winter, the Christmas tree in the living room, children playing in the household, a "happy," cheerful wife, and a hardworking husband.  The Helmers are the epitome of traditionalism. Here, the author uses those very stamps to slowly filter in how they are all part of a very large facade. They are all part of a huge illusion of comfort and joy which hides a massive crack in the pavement: the reality which lies beneath that illusion. These include the sacrifices that women make to perpetuate the image of "virtuous perfection" that they are expected to fulfill, the suppression of the rights of females, and the ridiculous expectations bestowed upon them which make the charade continue. 
Emotion- All of the examples of connections mentioned above elicit feelings of commiseration in the audience. In the case of A Doll's House, the play mainly caused shock when it was first staged.The rebellion of Nora was seen as immoral, and Ibsen caught a lot of backlash with his play. 

Certainly, he has an ethical comprehension of human life; however, his own feeling does not always dictate to him the moral law, which in each single case must and should be applied. Besides, as far as the present work is concerned, the effect of the resolution is weakened by the fact that the final scene is too long. Fædrelandet (The Country), Copenhagen, 22 December 1879.

However, the modern reader (and even the progressive reader of Ibsen's era) can understand the meaning that Ibsen intended to convey. Meaning is entirely relevant to the story that we can connect to it. Ibsen created meaning by creating a scenario which we can all relate to in terms of what is real and fake about it. He gave us the entire meaning to the point that it is still understood in today's modern times.
http://www.anglistik.uni-bayreuth.de/en/Studium/Intro__Material_LIT/meaning/index.html