Using Eloquent's ORM to insert usermeta.id into posts.usermeta_id - php

Question

I'm working on a user-generated content blog that allows a user to go through the whole upload process before being prompted to sign up. Basic flow: fill out form to pick username/basic info->upload blog post->prompt to sign up with email/password. The purpose of reversing the normal flow is to increase the UX and conversion rate and avoid a wall in the beginning.
Instead of migrating, I've just created the tables manually in PHPmyAdmin. I have 3 relational models: Usermeta->hasOne(App\Mopdels\Post), Post->belongsTo(App\Models\Usermeta), and User->belongsTo(App\Models\Usermeta).
What I'm having trouble with is once the user has created a username and submits the first form to the usermeta table, and then submits the second form to upload their blog post to the post table, it doesn't seem to be attaching the usermeta.id to posts.usermeta_id linking them together. I must be missing something or not attaching it correctly. Here's my StoryController:
<?php
namespace App\Controllers\Story;
use App\Models\Post;
use App\Models\User;
use App\Models\Usermeta;
use App\Controllers\Controller;
use Respect\Validation\Validator as v;
class StoryUploadController extends Controller
{
public function guidance($request, $response)
{
return $this->view->render($response, 'storyupload/guidance.twig');
}
//set up our the Upload Story class so the user can upload their story
//render the view 'uploadstory.twig'
public function getStoryUpload($request, $response)
{
return $this->view->render($response, 'storyupload/upload.twig');
}
// This method is called when the user submits the final form
public function postStoryUpload($request, $response, $id)
{
//set up our validation rules for our complete sign up form
$validation = $this->validator->validate($request, [
'title' => v::stringType()->notEmpty()->length(1, 80),
'body' => v::stringType()->notEmpty()->length(1, 2500),
]);
//if validation fails, stay on story upload page
if ($validation->failed()) {
return $response->withRedirect($this->router>pathFor('storyupload.upload'));
}
$user = Usermeta::find($id)->first();
//We can use our Post Model to send the form data to the database
$post = Post::create([
'title' => $request->getParam('title'),
'body' => $request->getParam('body'),
'category' => $request->getParam('category'),
'files' => $request->getParam('img_path'),
'usermeta_id' => usermeta()->attach($user->id),
]);
//after submit, redirect to completesignup page
return $response->withRedirect($this->router->pathFor('auth.completesignup'));
}
}
I continue to get the error 'usermeta_id cannot be null' so it's definitely not pulling the id from the usermeta table correctly.
I've used the create() method to send the usermeta data to the table in my Auth controller.
Would it be better to have all of my form submissions in the Auth controller and what is the proper way using my example to make sure that my posts.usermeta_id is linked to my usermeta.id?
The usermeta form is taken care of by my Auth Controller:
//render the view 'signup.twig'
public function getSignUp($request, $response)
{
return $this->view->render($response, 'auth/signup.twig');
}
// This method is called when the user submits the form
public function postSignUp($request, $response)
{
$validation = $this->validator->validate($request, [
'name' => v::notEmpty()->alpha(),
'username' => v::noWhitespace()->notEmpty()->UsernameAvailable(),
'city' => v::notEmpty()->alpha(),
'country' => v::notEmpty()->alpha(),
]);
//if validation fails, stay on signup page
if ($validation->failed()) {
return $response->withRedirect($this->router->pathFor('auth.signup'));
}
$usermeta = Usermeta::create([
'name' => $request->getParam('name'),
'username' => $request->getParam('username'),
'city' => $request->getParam('city'),
'country' => $request->getParam('country'),
'share_location' => $request->getParam('share_location'),
]);
//after submit, redirect to storyupload/guidance
return $response->withRedirect($this->router>pathFor('storyupload.guidance'));
}

Answer 1

I wrote quite a bit here. To jump directly to what I believe will solve your problem, see the "Your Issue" section. The rest is here as an educational exercise.
A Quick Intro to Laravel Relations
As you probably already know, "relations" in Laravel are virtual concepts that are derived from the hard data in the database. Because they are virtual, there is some overlap in the definition of relations.
When you say "Usermeta has one Post" - what this means is that the posts table will have a usermeta_id field.
When you say "Post belongs to Usermeta" - what this means is that the posts table will have a usermeta_id field.
Notice that these two relations map to the exact same field in the exact same table. Declaring one relation will declare the other by simple congruence. "Usermeta has one Post" and "Post belongs to Usermeta" are identical relations.
A Tweak to Your Relations
There's one other relation that share this same schema (the posts table have a usermeta_id field). That is "Usermeta has many Posts". The difference here is not in how the relations are stored to the database, but in how Laravel interprets the relations and in what queries Laravel will run.
When you say "Usermeta has one Post", Laravel will scan the database for the first Post with a matching usermeta_id and return that as an instance of the Usermeta model.
When you say "Usermeta has many Posts", Laravel will scan the database for all matching usermeta_ids and return them as a Collection of Usermeta models. You likely want this second behavior -- otherwise users won't be able to make a second post after they sign up.
Setting the usermeta_id Field
Laravel allows you to set database fields directly through a relationship. See their documentation on inserting related models for details.
Because many relationships are just ciphers for the same underlying schema, there's no need to insert or update a related model both ways. For instance, suppose we had the following two models:
class User extends Eloquent {
public function posts() {
return $this->hasMany("App\Post");
}
}
class Post extends Eloquent {
public function user() {
return $this->belongsTo("App\User");
}
}
In this case, the following two lines of code are identical and you only need to use one of them:
$post->user()->associate($user);
$user->posts()->save($post);
Both of these will have the same effect (setting the user_id field on the posts table)
The reason I mention this is that it looks like you're trying to double-dip in your code. You're using attach() (conceivably to set the usermeta_id) and you're also setting the usermeta_id directly. I've added a side-note on the attach method below - as I don't believe it's the right method, anyway.
To use Laravel's relations, you would want code like the following to set this field:
public function postStoryUpload($request, $response, $id)
{
//set up our validation rules for our complete sign up form
$validation = $this->validator->validate($request, [
'title' => v::stringType()->notEmpty()->length(1, 80),
'body' => v::stringType()->notEmpty()->length(1, 2500),
]);
//if validation fails, stay on story upload page
if ($validation->failed()) {
return $response->withRedirect($this->router>pathFor('storyupload.upload'));
}
$user = Usermeta::find($id)->first();
//We can use our Post Model to send the form data to the database
$post = Post::create([
'title' => $request->getParam('title'),
'body' => $request->getParam('body'),
'category' => $request->getParam('category'),
'files' => $request->getParam('img_path'),
]);
// Set the usermeta_id field
$post->usermeta()->associate($user);
// Save the model so we write changes to the database
$post->save();
//after submit, redirect to completesignup page
return $response->withRedirect($this->router->pathFor('auth.completesignup'));
}
Manually Setting the usermeta_id Field
Instead of using Laravel's relations to set this field, you can set the field manually. This can sometimes be cleaner, but it's less explicit and can lead to minor bugs if you aren't careful. To do this, you need to treat the usermeta_id field like any other field on your model.
$post->usermeta_id = $user->id;
This also works when mass assigning attributes using fill or create like so:
$post = \App\Post::create([
'title' => $title,
'body' => $body,
'usermeta_id' => $user->id
]);
$post->fill([
'title' => $title,
'body' => $body,
'usermeta_id' => $user->id
]);
Note that when manually setting the usermeta_id like this, you do not need to use any relationship methods. The following code is redundant:
$post->usermeta_id = $user->id;
$post->usermeta()->associate($user);
Your Issue (I Believe)
There's a caveat to mass assignment, however. Per the Laravel documentation, mass assignment requires you to fill out the model's fillable or guarded attributes.
This is one of the most common bugs, if not the most common bug, in any Laravel code - and it doesn't throw an obvious error so it's easy to miss. Consider the following model:
class Post extends Eloquent {
private $fillable = ["title", "body"];
}
If you attempt to mass assign the usermeta_id field like so:
$post = \App\Post::create([
'title' => $title,
'body' => $body,
'usermeta_id' => $user->id
]);
Then it will silently fail. No error is thrown and the Post is created but the usermeta_id field will be NULL - because it's not mass assignable. This is fixed by updating your model like so:
class Post extends Eloquent {
private $fillable = ["title", "body", "usermeta_id"];
}
I will repeat again, as I did above, that if using mass assignment like this you do not not need to use the associate or save relationship methods. This would be redundant. Therefore you can just set usermeta_id directly to $user->id without any of the usermeta()->associate() shenanigans.
The Bugs I Mentioned
I mentioned that manually setting the field like this can cause bugs. So let's actually discuss what some of those bugs are now instead of glossing over them.
If you update the relationship field manually, Laravel will be unaware that the two models are related until it reloads the model from the database. Consider the following two chunks of code:
$post = new Post();
$post->usermeta_id = $user->id;
dd( $post->usermeta->name );
$post = new Post();
$post->usermeta()->associate($user);
dd( $post->usermeta->name );
The first code block will fail, throwing the error "cannot read attribute of null object" -- because as far as Laravel is aware, $post->usermeta is NULL. You set $post->usermeta_id, but you didn't set $post->usermeta.
The second code block will work as expected, because by running the associate function it sets both usermeta_id and usermeta.
95% of the time this doesn't really cause any issues, however. If you're using an asynchronous API call to save the post and then a separate asynchronous API call to read the post at a later time, then Laravel will read the post from the database and properly set up the relation automatically when we sees the usermeta_id field is filled out.
Side-note On the attach() Method
Laravel uses different methods for saving different types of relations - because the different relations imply different underlying database fields.
associate: This sets the *_id field on the current model's table. For instance: $post->user()->associate($user) will set the user_id on the posts table
save: This sets the *_id field on the other model's table. For instance: $post->comments()->save($comment) will set the post_id on the comments table
attach: This sets both *_id fields on a linking table for many to many relationships. For instance, if you had a tag system then $post->tags()->attach($tag) would set post_id and tag_id on the post_tags table
It can be a bit tricky to remember which of these three functions you need. In general, there's a direct mapping from relation to function:
hasOne, hasMany --> save
belongsTo --> associate
belongsToMany --> attach