javascript - 如果没有找到结果则显示 div

Question

我有这个代码。 http://jsfiddle.net/n3EmN/171/ 如何在选中某些复选框但未找到结果时显示 div，并在找到结果时隐藏该 div？例如，当我选中复选框“red”和复选框“africa”时，没有找到结果，所以现在我必须显示一个 div，我该怎么做？

HTML

<div class="flowers-wrap">

  <h3 style="font-size:14px; font-weight:normal;">Available Flowers</h3>
  <p style="font-size:12px;"><strong>Filter flowers by colour:</strong></p>
  <form>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-colour" value="red" id="red" /> Red</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-colour" value="yellow" id="yellow" /> Yellow</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-colour" value="pink" id="pink" /> Pink</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-colour" value="purple" id="purple" /> Purple</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-colour" value="green" id="green" /> Green</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-colour" value="other" id="other" /> Other</label>
  </form>
  <p style="font-size:12px;"><strong>Filter flowers by size:</strong></p>
  <form>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-size" value="tiny" id="tiny" /> Tiny</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-size" value="small" id="small" /> Small</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-size" value="medium" id="medium" /> Medium</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-size" value="large" id="large" /> Large</label>
    <br>
    <label style="font-size:12px;">
      <input type="checkbox" name="fl-size" value="giant" id="giant" /> Giant</label>
  </form>

</div>

<div class="continents-wrap">

  <h3 style="font-size:14px; font-weight:normal;">Available Continents</h3>

  <div class="continents" style="font-size:12px;">
    <div>Africa
      <input type="checkbox" name="fl-cont" value="africa" id="africa" />
    </div>
    <div>Europe
      <input type="checkbox" name="fl-cont" value="europe" id="europe" />
    </div>
    <div>Asia
      <input type="checkbox" name="fl-cont" value="asia" id="asia" />
    </div>
    <div>North America
      <input type="checkbox" name="fl-cont" value="north-america" id="north-america" />
    </div>
    <div>South America
      <input type="checkbox" name="fl-cont" value="south-america" id="south-america" />
    </div>
    <div>Antarctica
      <input type="checkbox" name="fl-cont" value="antarctica" id="antarctica" />
    </div>
    <div>Australasia
      <input type="checkbox" name="fl-cont" value="australasia" id="australasia" />
    </div>
  </div>

</div>

<div class="flowers">
  <div class="flower" data-id="aloe" data-category="green small medium africa">Aloe</div>
  <div class="flower" data-id="lavendar" data-category="purple green medium africa europe">Lavender</div>
  <div class="flower" data-id="stinging-nettle" data-category="green large africa europe asia">Stinging Nettle</div>
  <div class="flower" data-id="gorse" data-category="green yellow large europe">Gorse</div>
  <div class="flower" data-id="hemp" data-category="green large asia">Hemp</div>
  <div class="flower" data-id="titan-arum" data-category="purple other giant asia">Titan Arum</div>
  <div class="flower" data-id="golden-wattle" data-category="green yellow large australasia">Golden Wattle</div>
  <div class="flower" data-id="purple-prairie-clover" data-category="purple green other medium north-america">Purple Prairie Clover</div>
  <div class="flower" data-id="camellia" data-category="pink other large north-america">Camellia</div>
  <div class="flower" data-id="scarlet-carnation" data-category="red medium north-america">Scarlet Carnation</div>
  <div class="flower" data-id="indian-paintbrush" data-category="red medium north-america">Indian Paintbrush</div>
  <div class="flower" data-id="moss-verbena" data-category="purple other small south-america">Moss Verbena</div>
  <div class="flower" data-id="climbing-dayflower" data-category="blue tiny south-america">Climbing Dayflower</div>
  <div class="flower" data-id="antarctic-pearlwort" data-category="green yellow large antarctica">Antarctic Pearlwort</div>
</div>

CSS

body {
  font-family: 'Arial';
  color: #646464;
}

.continents-wrap {
  float: left;
  width: 20%;
  margin: 0 5% 0 0;
  padding: 0;
}

.flowers-wrap {
  float: left;
  width: 20%;
  margin: 0 5% 0 0;
  padding: 0;
  position: relative;
}

.flowers {
  float: left;
  width: 50%;
}

.flowers div {
  float: left;
  width: 90%;
  height: 68px;
  line-height: 68px;
  padding: 0 5%;
  background: #eee;
  margin: 0 0 1px;
  position: relative;
}

JS

  var $filterCheckboxes = $('input[type="checkbox"]');

  $filterCheckboxes.on('change', function() {

  var selectedFilters = {};

  $filterCheckboxes.filter(':checked').each(function() {

    if (!selectedFilters.hasOwnProperty(this.name)) {
      selectedFilters[this.name] = [];
    }

    selectedFilters[this.name].push(this.value);

  });

  // create a collection containing all of the filterable elements
  var $filteredResults = $('.flower');

  // loop over the selected filter name -> (array) values pairs
  $.each(selectedFilters, function(name, filterValues) {

    // filter each .flower element
    $filteredResults = $filteredResults.filter(function() {

        var matched = false,
        currentFilterValues = $(this).data('category').split(' ');

      // loop over each category value in the current .flower's data-category
      $.each(currentFilterValues, function(_, currentFilterValue) {

        // if the current category exists in the selected filters array
        // set matched to true, and stop looping. as we're ORing in each
        // set of filters, we only need to match once

        if ($.inArray(currentFilterValue, filterValues) != -1) {
          matched = true;
          return false;
        }
      });

      // if matched is true the current .flower element is returned
      return matched;

    });
  });

  $('.flower').hide().filter($filteredResults).show();

});

Answer 1

您可以检查 jQuery 选择器结果的长度属性。由于 jQuery 选择器查找元素数组，因此您可以检查 jQuery 对象的 length 属性。

if ($filteredResults.length == 0) {
    $("#divID").show();
} else {
    $("#divID").hide();
}