查询解析以获取对象的状态

Question

I am developing a social application using parse. I have following data models for parse.com

User

• name (String)
• email (String)
• ...

Post

• tittle (String)
• description (String)
• User (Pointer)
• Like (Pointer)
• Comment (Pointer)
• LikeCount (Number)
• Comment Count (Number)

Like

• User (Pointer)
• Post (Pointer)

Comments

• text (String)
• User (Pointer)
• Post (Pointer)

Now when I fetch posts I also want to fetch additional information which is

1. If current user liked this post?
2. If current user commented on this post?

I am wondering If I can get all these info in one network call. I don't want to perform multiple network calls for each post.

Answer 1

In your query for fetching the post, you can indicate that you want the query to return also the related objects, like this:

...
query.include("User");
query.include("Like");
query.include("Comment");

or even

query.include("Like.User");

to get the Like object AND the User object related to that Like object

This will ensure that you get the full objects; not just the pointers to them.

However, these queries quickly become complex. I recommend you read the Parse tutorial for the Anypic app, and see how they have solved this. Anypic is for iOS only, but you should be able to understand the concepts. https://parse.com/tutorials/anypic