Polymer Dart - Can't access elements inside a template element

Question

I'm having trouble accessing the elements that are within <template if = "{{something}}">. I've read some posts published on the web and mainly the solution involves the use of MutationObserver. The problem is i've template elements chained with other template elements. Below's an illustration:

       <template repeat="{{container in containers}}">
        <!-- Tab content -->
        <div id="{{container.secondname}}" class="{{container.secondname}}">
          <template id="firstTemplate" if="{{currentContainer.photos.isEmpty}}">
              (...)
          </template>
          <template id="secondTemplate-{{container.name}}" if="{{currentContainer.photos.isNotEmpty}}">
            <div class="row">
              <div class="col col-xs-12 col-sm-12 col-md-12 col-lg-12">     
                <section class="centerStuff">
                  <template if="{{container.photosToDisplay.length < 1}}">
                    (...)
                  </template>
                  <template if="{{container.photosToDisplay.length > 0}}">
                      <template if="{{isInOverflow}}">
                        <div on-click="{{moveLeft}}" id="thumb-back"></div>
                      </template>    
                      <ul id="nav-{{container.secondname}}" class="navlistHorizontal">
                        <template repeat="{{photo in currentContainer.photosToDisplay}}">  
                          <li> 
                            <div class="mementoSpecialImage">
                              <div class="imageBoard">
                                <img src="{{photo.miniThumbnailToShow.src}}"
                                     class="image img-thumbnail"
                                     title="{{photo.title}}"
                                     on-click="{{showImage}}"
                                     id="{{photo.title}}"
                                     data-id="{{photo.id}}" >
                                </div>
                            </div> 

How can i proceed to access the img element?

Thanks for your help.

Answer 1

var img = this.querySelector('.imageBoard .image img-thumbnail') as ImageElement;