When should you use js frameworks?

Question

JavaScript

Hello. Question - when should you use js frameworks such as angular, meteor, vuejs and others? That is, because of what need will this framework be used in the project? Looking at the current situation, it sometimes seems like a framework is being used, just because it's popular. Explain, please, on fingers.

Answer 1

When there are many complex relationships between interface elements.
If the web interface can be divided into simple loosely coupled bricks like "pressed the button - the panel unfolded, pressed again - folded, and she sneeze, what's going on in all other elements" - a framework is not needed.
If there are connections between them in the spirit of "if I pressed this button, then you need to look at the state of that checkbox and if it is true, then do A and B, if false, then X, Y and Z, and then something else in the adjacent list then filter it and by the results, perhaps disable some elements" - you can't get anywhere. As the number of such connections grows, the amount of code and all sorts of checks grows exponentially, everything gets tangled up in a Gordian knot.