How to loop through children and grandchildren in laravel - php

Question

I'm trying to find a way to do \App\Goal::find(1)->children and get returned all children, and childrens children.
With the database pasted below I want
\App\Goal::find(1)->children
to return
2, 4 and 5. Currently I can only do \App\Goal::find(1)->goals, which returns only 2 and 4
I have a database like this:
id user_id goal_id objective
1 1 NULL Get rich
2 1 1 Save $5
3 1 NULL Learn to cook
4 1 1 Save $10,000
5 1 4 Buy stocks
6 1 5 Buy 5x Intel
7 1 5 Buy 5x AMD
How would you go about creating the children() function in the Goal model?
Please ask if any important info is missing from this
Edit:
Goal.php:
public function user()
{
return $this->belongsToUser(User::class);
}
public function goals()
{
return $this->hasMany(Goal::class, 'goal_id')
}
When I run \App\Goals::find(1)->goals in the GoalController it returns the children of itself (with id 2 and 4 from the example db table), but not its grandchildren...
ID 5 from the example table has a parent of id 4, which itself has a parent id of 1.
So how could I get \App\Goal::find(1)->children or \App\Goal::find(1)->goals to return its grandchildren, and their children etc?

Answer 1

So, assuming the table you've posted is the goals table, related to App\Goal...
If you have these two relationships set up on the model:
public function children()
{
return $this->hasMany(Goal::class, 'parent_id');
}
public function childrenRecursive()
{
return $this->children()->with('children');
}
You can call Goal::with('childrenRecursive')->get() which will return a nested collection of all the children and children's children.
If you'd like all of the children in a flat array, you could do something like this:
public function getFamilyAttribute()
{
$family = collect([]);
$children = $this->children;
while (!is_null($children )) {
$family->push($children);
$children = $children->children;
}
return $family;
}