Controller and View Chunks

# Controller
class PurchaseOrdersController < ApplicationController
    ....

    def modify
        @pr = PurchaseRequest.find(params[:prid])
        @po = @pr.purchase_orders.first

        respond_to :html
    end

# View
.row
  == render '/partials/nav_pr'

  .col-md-8 ng-controller="PurchaseOrderEditCtrl"
    .row
      .col-md-12
        .card
          .card-body
            h5.card-title.text-secondary
              i.fas.fa-feather-alt.text-warning&nbsp;
              | PR No. #{ @pr.pr_number }
              span.text-warning
                | &nbsp;/&nbsp;
              | Purchase Orders

            hr.bg-light.mb-5

            form
              .form-group.row
                label.col-sm-3.col-form-label
                  | Mode of Proc.
                .col-sm-5
                  select.custom-select.mr-sm-2 ng-init="po.mode_proc='#{@po.mode_proc}'" ng-model="po.mode_proc"
                    option value=""
                      | Choose...
                    option value="Shopping" ng-selected="po.mode_proc == '#{@po.mode_proc}'"
                      | Shopping
                    option value="Small Value Procurement" ng-selected="po.mode_proc == '#{@po.mode_proc}'"
                      | Small Value Procurement

              .form-group.row ng-init="po.po_date='#{@po.po_date}'"
                label.col-sm-3.col-form-label
                  | PO Date
                .col-sm-5
                  input.form-control.format-po-num date-input="" type="date" ng-model="po.po_date" ng-model-options="{timezone:'UTC'}"

    - @pr.purchase_orders.each_with_index do |s,i|
      .row
        .col-md-12
          .card
            .card-body
              form

                .form-group.row
                  label.col-sm-3.col-form-label
                    | Supplier:
                  .col-sm-9
                    input.form-control-plaintext readonly="" value="#{s.supplier_name}" ng-init="po.suppliers[#{i}].supplier_name='#{s.supplier_name}'"

                .form-group.row ng-init="po.suppliers[#{i}].supplier_address='#{s.supplier_address}'"
                  label.col-sm-3.col-form-label
                    | Address
                  .col-sm-9
                    input.form-control placeholder="ie. TAGUM CITY" ng-model="po.suppliers[#{i}].supplier_address"

                .form-group.row ng-init="po.suppliers[#{i}].po_number='#{s.po_number}'"
                  label.col-sm-3.col-form-label
                    | PO No.
                  .col-sm-5
                    input.form-control.format-po-num placeholder="00-00-0000" ng-model="po.suppliers[#{i}].po_number"

                .text-center

                  button.btn.btn-light.rounded-circle.po-update poid="#{s.id}" arrindex="#{i}" type="button"
                    i.text-primary.fas.fa-check

                  a.float-right href="/po/#{s.id}.pdf" target="_blank" style="margin-top:10px;"
                    i.far.fa-file-pdf.fa-lg