如何告诉我的simple_form对象返回仅包含选定ID而不包含任何空值的数组？

Question

So I have a simple_form object that looks like this:

<%= f.input :parents, collection: (@node.family_tree.nodes - @node.parents - [@node]).uniq, as: :check_boxes, label: "Parent 1" %>

This produces HTML that looks like this:

<div class="node_parents">
<label>Parent 1</label>
<input id="node_parents_13" name="node[parents][]" type="checkbox" value="13" /><label>Jack</label>
<input id="node_parents_35" name="node[parents][]" type="checkbox" value="35" /><label>Testy</label>
<input id="node_parents_37" name="node[parents][]" type="checkbox" value="37" /><label>Resty</label>
<input id="node_parents_36" name="node[parents][]" type="checkbox" value="36" /><label>Mesty</label>
<input name="node[parents][]" type="hidden" value="" />
</div>

When I fill out 2 of the 4 objects, my log looks like this:

Parameters: {"utf8"=>"✓", "authenticity_token"=>"F1HGLwIjDG3VaIYlnsu7NbROEiWBO8xqJtjh5MreI9E=", "node"=>{"name"=>"Lesty", "parents"=>["13", "35", "", ""], "family_tree_id"=>"2"}, "commit"=>"Update Node", "id"=>"38"}

Rather than it sending the params[:parents] as a 4-element array with 2 empty/nil values, I would rather it just send a 2-element array.

How do I do that?

Answer 1

I don't know if you really need to change what is sent by the form, or if you can just filter out the blank values in the controller before doing anything with them?

If you do want to avoid sending empty values then you will need to do something with javascript on form submit, to alter the params from the form before they are submitted. It's definitely much simpler to let the form submit the blanks and filter them out in the controller, however.

To do it with javascript, you'll need to do something like this: i'm assuming you're using jQuery here. The approach i have chosen is to change the submit button so it calls a function instead of submitting the form. The function disables the empty inputs (thus not including them in the form data) and then submits the form.

Add a js function to the page

<script type="text/javascript">
  var processForm = function(){
    //disable unchecked checkboxes
    $("#myForm input[type=checkbox]").not(":checked").attr("disabled", "disabled");
    $("#myForm").submit();
  };
</script>

then replace your submit button with this:

<%= button_to_function "Submit", "processForm();" %>

Answer 2

Try this

params[:node][:parents].reject!{|p| p == ""} 

or

params[:node][:parents].reject!(&:blank?)