Batch intersection of points with line

Question

I have 1.000 point layers (shapefiles).

How can I find points intersected to a line without defining the points layer?

Because defining thousand layer takes time. And I dont wanna merge those point layers because I need it for visual purpose.

I make a custome line which has branch. I already have a solution to 'sum' each value in points that intersected in line from previous question but not finished. This is the function :

aggregate(layer:='point1',aggregate:='sum',expression:="number",filter:=intersects($geometry, geometry(@parent))) + aggregate(layer:='point2',aggregate:='sum',expression:="number",filter:=intersects($geometry, geometry(@parent)))

1st problem : i got wrong sum result after the first line i draw ( i want duplicate points only count once)

2nd probelm : imagine i have 1000 layers of points, it is so hard to type them all. So i need generalization for N points layer or any solution which doesnt require to define points layer.

UPDATE

I was thinking of another option to get correct sum number.

The picture above is the attribute table for drawn line to get intersecting point and get the point attribute.

Maybe we can merge these two column, so the yellow-highlighted line one group into one.

Answer 1

You will have to loop through all your project's layers and pass them in the aggregate function with this expression:

with_variable('point_layers', array_filter(
    array_foreach(@map_layers, layer_property( @element, 'name')),  --< get a list of all layers names
@element <> layer_property(@layer, 'name') ), --< filter current layer out of the list

array_count( --< function to add all numbers in an array (you have to make it)
    array_filter( array_foreach( @point_layers ,  --< loop through all layers names
         aggregate(layer:=@element ,
         aggregate:='sum', 
         expression:="att",  --< the attribute
         filter:=intersects($geometry, geometry(@parent)))),
    @element is not NULL)--< filter all NULL values
    ))

I haven't found a function to add all numbers in an array in the qgis expression builder, so you'll have to create one by copying this in the function editor (next to the expression tab):

from qgis.core import *
from qgis.gui import *

@qgsfunction(args='auto', group='Custom')
def array_count(array, feature, parent):
    """
    Calculates Sum of numbers in an array.
    <h2>Example usage:</h2>
    <ul>
      <li>array_count(array(1, 2, 3)) -> 6</li>
    </ul>
    """
    arrayCount = sum(array)
    return arrayCount

It might be a bit slow for 1000 point layers. edit: you have to filter current layer out of the list for it to work