Within Your theme

README.md

Download modal

field.html.twig

{#
/**
 * @file
 * Theme override for a field.
 *
 * To override output, copy the "field.html.twig" from the templates directory
 * to your theme's directory and customize it, just like customizing other
 * Drupal templates such as page.html.twig or node.html.twig.
 *
 * Instead of overriding the theming for all fields, you can also just override
 * theming for a subset of fields using
 * @link themeable Theme hook suggestions. @endlink For example,
 * here are some theme hook suggestions that can be used for a field_foo field
 * on an article node type:
 * - field--node--field-foo--article.html.twig
 * - field--node--field-foo.html.twig
 * - field--node--article.html.twig
 * - field--field-foo.html.twig
 * - field--text-with-summary.html.twig
 * - field.html.twig
 *
 * Available variables:
 * - attributes: HTML attributes for the containing element.
 * - label_hidden: Whether to show the field label or not.
 * - title_attributes: HTML attributes for the title.
 * - label: The label for the field.
 * - multiple: TRUE if a field can contain multiple items.
 * - items: List of all the field items. Each item contains:
 *   - attributes: List of HTML attributes for each item.
 *   - content: The field item's content.
 * - entity_type: The entity type to which the field belongs.
 * - field_name: The name of the field.
 * - field_type: The type of the field.
 * - label_display: The display settings for the label.
 *
 *
 * @see template_preprocess_field()
 */
#}
{%
  set classes = [
    'field',
    'field--name-' ~ field_name|clean_class,
    'field--type-' ~ field_type|clean_class,
    'field--label-' ~ label_display,
  ]
%}
{%
  set title_classes = [
    'field__label',
    label_display == 'visually_hidden' ? 'visually-hidden',
  ]
%}
{% if label_hidden %}
  {% if multiple %}
    <div{{ attributes.addClass(classes, 'field__items') }}>
      {% for item in items %}
        <div{{ item.attributes.addClass('field__item') }}>{{ item.content }}</div>
      {% endfor %}
    </div>
  {% else %}
    {% for item in items %}
      <div{{ attributes.addClass(classes, 'field__item') }}>
        {%- if "Download" in item.content|raw -%}
        <!-- Button trigger modal -->
        <button type="button" class="button button-action" data-toggle="modal" data-target="#exampleModalCenter">Download <i class="fas fa-download" aria-hidden="true"></i>
        </button>
        <!-- Modal -->
        <div class="modal fade" id="exampleModalCenter" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
          <div class="modal-dialog modal-dialog-centered" role="document">
            <div class="modal-content">
              <div class="modal-header">
                <h5 class="modal-title" id="exampleModalLongTitle">Download</h5>
                <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                  <span aria-hidden="true">&times;</span>
                </button>
              </div>
              <div class="modal-body">
                {# {{ item.content }} #}
                {% if item.content['#url'] %}
                  <a href="{{ item.content['#url'] }}" download="{{ item.content['#url']|raw|render|split('/')|last }}">
                    {{ item.content['#title'] }} Original File
                  </a>
                {% else %}
                  <a class="btn disabled" href="">
                    Link Currently Unavailable
                  </a>
                {% endif %}
                <p>Some items may be under copyright. You are responsible for checking Use and Reproduction terms listed for thie item (below). By downloading, you agree to the <a href="/terms-use">Terms of Use.</a></p>
              </div>
            </div>
          </div>
        </div>
        {%- else -%}
          {{ item.content }}
        {%- endif -%}
      </div>
    {% endfor %}
  {% endif %}
{% else %}
  <div{{ attributes.addClass(classes) }}>
    <div{{ title_attributes.addClass(title_classes) }}>{{ label }}</div>
    {% if multiple %}
      <div class='field__items'>
    {% endif %}
    {% for item in items %}
      <div{{ item.attributes.addClass('field__item') }}>
        {%- if "Download" in item.content|raw -%}
        <!-- Button trigger modal -->
        <button type="button" class="button button-action" data-toggle="modal" data-target="#exampleModalCenter">Download <i class="fas fa-download" aria-hidden="true"></i>
        </button>
        <!-- Modal -->
        <div class="modal fade" id="exampleModalCenter" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
          <div class="modal-dialog modal-dialog-centered" role="document">
            <div class="modal-content">
              <div class="modal-header">
                <h5 class="modal-title" id="exampleModalLongTitle">Download</h5>
                <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                  <span aria-hidden="true">&times;</span>
                </button>
              </div>
              <div class="modal-body">
                {# {{ item.content }} #}
                {% if item.content['#url'] %}
                  <a href="{{ item.content['#url'] }}" download="{{ item.content['#url']|raw|render|split('/')|last }}">
                    {{ item.content['#title'] }} Original File
                  </a>
                {% else %}
                  <a class="btn disabled" href="">
                    Link Currently Unavailable
                  </a>
                {% endif %}
                <p>Some items may be under copyright. You are responsible for checking Use and Reproduction terms listed for thie item (below). By downloading, you agree to the <a href="/terms-use">Terms of Use.</a></p>
              </div>
            </div>
          </div>
        </div>
        {%- else -%}
          {{ item.content }}
        {%- endif -%}
      </div>
    {% endfor %}
    {% if multiple %}
      </div>
    {% endif %}
  </div>
{% endif %}

Ah, based on your prompting I discovered that Bootstrap provides its own modal JS as part of the theme. I didn't even think to check our own theme for an included modal capability. 🤦‍♂️