在 Rails 中使用“f.input 集合”的 onChange 方法

Question

I have this dropdown:

<%= f.input :window_type, collection: @window, selected: @window.first, label: "Window Type", input_html: {onChange: "changePlaceholder(this)", type: "text"} %>

I want to capture when you change an option there, so i can change a placeholder with javascript. So i made this function to check that i was receiving the expected value:

function changePlaceholder(this){
  console.log("This is " + JSON.stringify(this));
}

But when i try to run it, it gives an error with the "this" variable, it says unexpected token. Before i had to change the C from onChange to caps because it was not like that so maybe i'm missing something else with the "this".

I could use a select_chosen, but i prefer the f.input so i can have control over the parameter name in the controller. Thanks.

Answer 1

At the end the answer was simple, something like this works. You have to add a class to the input like:

<%= f.input :topic1, collection: @inputs,include_blank: false,label: "First Input To Read From (Referenced as F)",input_html: {class: "topic1", type: "text" } %>

And then, with jquery:

$(document).on("change", "select.topic1", function(e){
  var topic1 = $(this).children("option:selected").val();
}