Wednesday, May 18, 2016

HTML5 Input Types for Oracle JET

I read an interesting question today, "Can you use HTML5 Input Types with Oracle JET's ojInputText?" Of course, the answer is "Yes" (the answer is always Yes). A better question is "How do you use HTML5 Input Types with Oracle JET's ojInputText?" OK, before we go there, let's answer the "Why" question: "Why would you use HTML5 Input Types with Oracle JET's ojInputText?" Oracle JET already includes number, text, and date input types, all styled according to the Oracle Alta specification. The reason for HTML5 Input Types? Device support. The idea behind HTML5 input types is to allow each device to display the most appropriate input method for a specific input type. This allows mobile web apps to maintain consistency with native mobile apps. For this reason, I am a HUGE fan of HTML5 input types. Note: desktop browsers don't have very good support for HTML5 Input Types.

Let's move onto the "How" question. Can you just set the type attribute of an ojInputText to "date" and get an HTML5 date input? No. Oracle JET will reset the type attribute to "text." The trick is to register a MutationObserver to listen for changes to the type attribute, and then reset it back to date (or whatever HTML5 input type you desire). Next question: How do I assign a MutationObserver to an instance of ojInputText? At this time, the best way I know to do this is with a knockout custom binding handler. You may remember that we used a custom binding handler last time we extended ojInputText (and then reused it a few more times). The reason for registering a ko.bindingHandler is to give us life cycle management events: we know when the DOM element is available and can enhance that element as we see fit. Here is an example of a custom component named html5DateInputText that extends ojInputText through ko.bindingHandlers. On initialization, the bindingHandler configures a MutationObserver that ensures the type attribute is always date. If you don't see a browser-specific date picker in the following example, then your browser might not support the date HTML5 input type. That doesn't mean the example is broken. It still works (depending on how you define the word "works") and falls back gracefully to a plain ojInputText.

Here is the custom binding handler:

var observerConfig = {
  attributes: true,
  childList: true,
  characterData: true
// Custom binding handler that wraps ojInputText and provides extra functionality
ko.bindingHandlers.html5DateInputText = {
    // setup extension to ojInputText as well as register event handlers
    init: function(element, valueAccessor, allBindingsAccessor, ctx) {
      var options = allBindingsAccessor().ojInputTextOptions || {};

      var observer = new MutationObserver(function(mutations) {
        ko.utils.arrayForEach(mutations, function(mutation) {
          if (mutation.type === 'attributes') {
            if (mutation.attributeName === 'type') {
              var $target = $(;
              if ($target.attr('type') !== 'date') {
                $target.attr('type', 'date');
      observer.observe(element, observerConfig);
          'ojoptionchange': function (event, data) {
            // use option === "value" for final value
            // use option === "rawValue" for each character
            if(data.option === "rawValue") {
              var val = data.value;
              var observable = valueAccessor();

      //handle disposal (if KO removes by the template binding)
      ko.utils.domNodeDisposal.addDisposeCallback(element, function() {
        console.log("ojInputText destroyed");
    // This is how we update the UI based on observable changes
    update: function(element, valueAccessor) {
      var value = ko.utils.unwrapObservable(valueAccessor());
      $(element).ojInputText("option", "value", value);

If you want a different input type (tel, number, email and so on), then change lines 19 and 20 to match your target input type.

Note: The ojInputText Alta skin includes padding: 0 5px. The Chrome HTML5 Date spinners weren't centered using that padding so I added a line of CSS to reset padding to 5px on all sides.

No comments:

Post a Comment