使用Laravel的复杂注释，标签，投票，收藏夹数据库关系

Question

I am trying to learn HABTM and Polymorphic Relationships by building a small but complex application in Laravel 4.2. It takes in links and lets users interact with the content and each other via keywords like tag, comment, vote, favorite, and follow. I have honestly been working on this for about 3 days and feel like I am just spinning my wheels in the mud. Here's the breakdown -

Models:

User, Link, Tag, Comment, Vote, Favorite, Follow

Super basic use cases:

USER -> ACTION   -> TARGET
User -> Submit   -> Link, Tag, Comment
User -> Tag      -> User, Link
User -> Comment  -> User, Link
User -> Vote     -> Tag, Comment
User -> Favorite -> User, Link, Tag, Comment
User -> Follow   -> User, Tag

(assumed) Tables:

users            [id, username]
links            [id, user_id, url]
tags             [id, user_id, text]
commentables     [id, user_id, commentable, commentable_id, text] //how do i handle comment replies?
taggables        [id, user_id, taggable, taggable_id, weight]
votables         [id, user_id, voteable, voteable_od, vote]
favorables       [id, user_id, favorable, favorable_id]
followable       [id, user_id, followable, followable_id]

From here .. I'm not sure that I'm doing it right. I keep getting caught up in the different ways to define a relationship and I'm just wanting to understand the design completely

What do my model files look like? What cases I might use belongsToMany vs morphToMany? Is this even the right approach or should I explore using pivot tables? I would appreciate some pointers on what I need to be learning to implement this correctly

Here is what my User.php will probably look like, but I'm not sure what the returns should actually be since I don't quite understand the relationship's wants/needs

(assumed) User.php

usersFavored()    // Users which this User has Favored
usersFollowed()   // Users which this User has Followed
linksSubmitted()  // Links created by the User in the DB
linksFavored()    // ...
tagsOnSelf()      // Tags attached to this User by other Users
tagsCreated()     // Tags which the User created in the DB
tags()            // Tags which the User was the first to attach to a Link
tagsVoted()       // Tags on which the User has Voted across the entire site
tagsFavored()     // ...
tagsFollowed()    // ...
commentsOnSelf()  // ...
comments()        // Comments across the site
commentsFavored() // ...
votesOnSelf()     // ...
votes()           // Votes across the site
favorites()       // Favorites across the site
follows()         // Follows across the site

I feel like I'm close to making this work. I have the views and routes ready because I've rebuilt this project about four times. I just need to wrestle all of this database relationship logic so I can make the app come to life. Your input is much appreciated!

Answer 1

here are some of my thoughts

1. I was really confused about whether to use belongsToMany vs morphToMany. But now as I get more familiar with Laravel, it becomes clear to me that what morphToMany can do can be done by belongsToMany too. So you need only master belongsToMany. It's powerful enough. However, if you want to know the difference between the two relationships, here's the explanation on when you should use either of them. For belongsToMany, you just want to fetch some entities and you do not care about their states. However, if you need to differentiate the states between those entities such as votes(two types: up vote and down vote), you could use morphToMany.
2. For your assumed User.php, each of those functions should just return a sql query instance. These functions are used in controller to get results. Simply put, functions in models are just different sql statements wrapped well to use in controllers. In this way you separate business logic from sql selection statements.
3. When you call functions in models, make sure you call ->get() to ensure the execution of sql statement. In essence, each functions in models only return an unexecuted sql statement. If you want to get the results of sql statements, you need to call ->get().

Hope this helps. Ready to help if you have more questions