I have an application where users can like posts. I use relationships when a user decides to like a post like this:
ParseObject postObject = ParseObject(‘Post’);
postObject.addRelation(‘likes’, [ParseObject(‘User’)…set(‘objectId’, ‘000’)]);
await postObject();
and if user dislike:
ParseObject postObject = ParseObject(‘Post’);
postObject.removeRelation(‘likes’, [ParseObject(‘User’)…set(‘objectId’, ‘000’)]);
await postObject();
How do you know if a user has already liked a particular post?
I was using likes as lists before so for each post I just had to do:
if (likes.contains(‘000’)) {
likes.remove(‘000’);
} else {
likes.add(‘000’);
}
To know if I should add or remove the user’s like.
How do I do the same using relations so I know if I should use addRelation or removeRelation?
Thanks
Related
relative to this answer: How to make follower-following system with django model
I will like to know how to get all the post of the user that I'm following just in case I'll want to add that extra functionality in the future.
You will have an another Model Post associated with User.
class Post(models.Model):
description = models.TextField()
user = models.ForeignKey("User", related_name="posts")
Getting all posts of following_user_id, you can achieve by below query
following_user_ids = request.user.followers.all().values_list("following_user_id", flat=True)
posts = Post.objects.filter(user__in=following_user_ids)
request.user is the logged-in user, related_name="followers" is used get all associated records from UserFollowing Model. values_list() will return the following_user_id in list form than pass the returned list in Post
I want to retrieve the user's photo and display it in a thumbnail form which i have stored in public/assets/uploads/thumbnail/. I tried auth()->user()->user_detail->file_name but I can't get it to work. How do you do it ?
you have to first define a relationship if they are stored in different table
like i did in model
public function imagedata() {
return $this->hasMany(Images::class, 'listID', 'id');
}
and after that when you get the user just call this method like this
$listingimg = Listings::findOrfail($id);
and for calling the relationship
foreach (listingimg as $singleIlisting) {
$singleIlisting->imagedata;
}
modify the code according your needs as if needed and by the way relatio is one to many
I have three tables: users, emails,attachments. User table is connected with emails by user_id. Emails table is connected with attachments by email_id.
My question is: How should I make it look eloquent in laravel to get all users their emails and their attachments? (I know how get all user and they emails but I don't know how to add attachments.)
Depending on your database relationship,you may declare a relationship method in your Email model, for example:
// One to One (If Email has only one attachment)
public function attachment()
{
return $this->hasOne(Attachment::class);
}
Otherwise:
// One to Many (If Email contains more than one attachment)
public function attachments()
{
return $this->hasMany(Attachment::class);
}
To retrieve the related attachment(s) from Email model when reading a user using id, you may try something like this:
$user = User::with('email.attachment')->find(1); // For One-to-One
$user = User::with('email.attachments')->find(1); // For One-to-Many
Hope you've already declared the relationship method in the User model for Email model using the method name email.
Note: make sure, you have used right namespace for models. It may work if you've done everything right and followed the Laravel convention, otherwise do some research. Also check the documentation.
I'm encountering an annoying problem with Laravel and I'm hoping someone knows a way to override it...
This is for a system that allows sales reps to see inventory in their territories. I'm building an editor to allow our sales manager to go in and update the store ACL so he can manage his reps.
I have two related models:
class Store extends Eloquent {
public function StoreACLEntries()
{
return $this->hasMany("StoreACLEntry", "store_id");
}
}
class StoreACLEntry extends Eloquent {
public function Store()
{
return $this->belongsTo("Store");
}
}
The idea here is that a Store can have many entries in the ACL table.
The problem is this: I built a page which interacts with the server via AJAX. The manager can search in a variety of different ways and see the stores and the current restrictions for each from the ACL. My controller performs the search and returns the data (via AJAX) like this:
$stores = Store::where("searchCondition", "=", "whatever")
->with("StoreACLEntries")
->get();
return Response::json(array('stores' => $stores->toArray()));
The response that the client receives looks like this:
{
id: "some ID value",
store_ac_lentries: [
created_at: "2014-10-14 08:13:20"
field: "salesrep"
id: "1"
store_id: "5152-USA"
updated_at: "2014-10-14 08:13:20"
value: "salesrep ID value"
]
}
The problem is with the way the StoreACLEntries name is mutilated: it becomes store_ac_lentries. I've done a little digging and discovered it's the toArray method that's inserting those funky underscores.
So I have two questions: "why?" and "how do I stop it from doing that?"
It has something in common with automatic changing camelCase into snake_case. You should try to change your function name from StoreACLEntries to storeaclentries (lowercase) to remove this effect.
I've created a OData V4 Service described in the articles on the ASP.NET Homepage.
I basically have a table Events where I assign Guests to. I need additional information to this many to many relationship, so I have created a EventGuest table.
Inserting Events and inserting Guests via OData just works fine. It just doesn't want to work, as soon as I want to insert related entities.
This is my Controller-Code:
public async Task<IHttpActionResult> Post(EventGuest eventGuest)
{
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
_db.EventGuest.AddOrUpdate(eventGuest);
await _db.SaveChangesAsync();
return Created(eventGuest);
}
And this is how I want to insert the relationship. For the Client Code I use the official T4 template.
var ev = container.Event.FirstOrDefault();
var guest = container.Guest.FirstOrDefault();
var evGuest = new EventGuest();
evGuest.Guid = Guid.NewGuid();
container.AddObject("EventGuest", evGuest);
container.SetLink(evGuest, "Event", ev);
container.SetLink(evGuest, "Guest", guest);
container.SaveChanges();
The request sent to the Server doesn't look too bad for me:
{"#odata.type":"#Entities.EventGuest","CreationTimestamp":"0001-01-01T00:00:00Z","Guid":"adf500e3-e3a1-4841-883e-2322ed863321","ID":0,"Event#odata.bind":"http://localhost/odata/Event(1)","Guest#odata.bind":"http://localhost/odata/Guest(1)"}
So the Server tries to use #odata.bind, but unfortunately in the POST-Method of the Controller the referenced entities "Guest" and "Event" are null.
Have you tried following the example at the MSDN Documentation? I noticed it always uses AddLink rather than SetLink, even in the SetLink documentation.
MSN Article is here: DataServiceContext.SetLink Method