30 - HTML Element Type Check

by steen_hansen

HTML

<!DOCTYPE html><meta charset="utf-8" />
<title id='title-id'>30 HTML Element Type Checks</title>



  
<div id='js-div' style="width:50%; ">
  <a href='https://github.com/steenhansen/type-czech'  target="_blank" class='git-hub'>GitHub Package</a>
  <div id='js-code'>the javascript</div>
</div>


<div id="the-explanation" style="width:50%"  class='code-scroll'>
  <div class='an-explantion'>30 - HTML Element Type Checks</div>
  
  <div id='explanation-text'>
    <br>

    Error found by PRE_check_changeToSubmit() when attempting to set a-table to
    have the type of 'submit'.
    <table id='a-table'>

      <tr>
        <th style='text-align: left;'>function changeToSubmit(id)</th>
        <th>Change HTML Element to Submit Button</th>
      </tr>

      <tr><th>
          OK, change plain button into Submit button
      </th><th>
          <button id='submit-button' type="button" disabled>Plain-Button</button> now a submit button
      </th></tr>
     
      <tr><th>
          <span class='red-explanation'>Error</span>, change a-table into a Submit button
      </th><th>
        <div class="red-explanation">a-table cannot be a Submit button</div>
      </th></tr>

    </table>

<hr>

         HTML elements can have their types checked.
         
<pre>
a_div = document.querySelector('div')
div_type = type_czech.typeFinal(a_div)    //HTMLDivElement
</pre>


         HTML elements can also be queried for their prototypes chain.


<pre>
a_div = document.querySelector('div')
div_protos=type_czech.typeProtos(a_div)//["HTMLDivElement","HTMLElement 
</pre>


And finally, HTML elements can also be asked their object type.
<pre>
a_div = document.querySelector('div')
isa_HTMLElem = type_czech.typeIsA(a_div, 'HTMLElement')  // true
</pre>



<hr>



Two errors are found by PRE_check_alterImgHref() when trying to set a-div to have a location
address, in blue text. And, when incorrectly setting a-picture's src location to a local anchor
in green text.
<table>

  <tr>
    <th...