counter.html

<script type="text/x-red" data-template-name="counter">
    <div class="form-row">
        <label for="node-input-name"><i class="fa fa-tag"></i> Name</label>
        <input type="text" id="node-input-name" placeholder="Name">
    </div>
    <div class="form-row">
        <label for="node-input-init"><i class="fa fa-cog"></i> Initial Count</label>
        <input type="text" id="node-input-init" placeholder="0">
    </div>
    <div class="form-row">
        <label for="node-input-step"><i class="fa fa-forward"></i> Default Step</label>
        <input type="text" id="node-input-step" placeholder="1">
    </div>
    <div class="form-row">
        <label for="node-input-lower"><i class="fa fa-arrow-down"></i> Lower Limit</label>
        <input type="text" id="node-input-lower" placeholder="unlimited">
    </div>
    <div class="form-row">
        <label for="node-input-upper"><i class="fa fa-arrow-up"></i> Upper Limit</label>
        <input type="text" id="node-input-upper" placeholder="unlimited">
    </div>
    <div class="form-row">
        <label for="node-input-mode"><i class="fa fa-tasks"></i> Mode</label>
        <select id="node-input-mode">
            <option value="increment">increment</option>
            <option value="decrement">decrement</option>
        </select>
    </div>
    <div class="form-row">
        <label for="node-input-outputs"><i class="fa fa-random"></i> Outputs</label>
        <select id="node-input-outputs">
            <option value="1">single (1)</option>
            <option value="2">split (2)</option>
        </select>
    </div>
</script>

<script type="text/x-red" data-help-name="counter">
    <p>A simple node to create a counter with messages.</p>
    <p>By default the counter will be incremented for every inbound message and append the current count to <code>msg.count</code>.</p>
    <p><strong>Configuration</strong><br/>
    <ul>
      <li><code>Initial Count</code>: The initial count can be set in the configuration. By default it will be <strong>zero</strong> at start.</li>
      <li><code>Default Step</code>: Default amount that will be incremented or decremented on every incoming message.</li>
      <li><code>Lower Limit</code>: Optional limitation of the lower count limit. Will add <code>countLowerLimitReached</code> to <code>msg</code> if reached.</li>
      <li><code>Upper Limit</code>: Optional limitation of the upper count limit. Will add <code>countUpperLimitReached</code> to <code>msg</code> if reached.</li>
      <li><code>Mode</code>: Determine if count value should be incremented or decremented on every incoming message.</li>
      <li><code>Outputs</code>: Selects the output format of the counter. For more info read below.</li>
    </ul>
    </p>
    <p><strong>Output</strong><br/>
    There are two output options for the counter value:
    <ul>
      <li><strong>single</strong>: The actual count will be appended to <code>msg.count</code> of the original <code>msg</code>.</li>
      <li><strong>split</strong>: The node will become two outputs, first will return the count as <code>msg.payload</code> and possible limitation info, the second returns the untouched original <code>msg</code>.</li>
    </ul>
    </p>
    <p><strong>Control</strong><br/>
    It's possible to control the counter with incoming <code>msg</code> properties:
    <ul>
      <li><code>msg.increment</code>: counter will be incremented by the given value.</li>
      <li><code>msg.decrement</code>: counter will be decremented by the given value.</li>
      <li><code>msg.reset</code>: resets the counter to it's initial count, or to the given value, when it's a number.</li>
    </ul>
    </p>
</script>

<script type="text/javascript">
    RED.nodes.registerType("counter", {
      category: "function",
      defaults: {
          name: {value:""},
          init: {value:"0"},
          step: {value:"1"},
          lower: {value:null},
          upper: {value:null},
          mode: {value:"increment"},
          outputs: {value:"1"}
      },
      color:"#e2d96e",
      inputs: 1,
      outputs: 1,
      icon: "counter.png",
      label: function() {
          return this.name || "counter";
      },
      labelStyle: function() {
          return this.name ? "node_label_italic" : "";
      },
      oneditprepare: function() {
          this.init = this.init || 0;
          this.step = this.step || 1;
          this.lower = this.lower || null;
          this.upper = this.upper || null;
          this.mode = this.mode || "increment";
          this.outputs = this.outputs || 1;
      }
    });
</script>