Description
============================================================

A list item containing a trait (pro/con), together with some JS that lets the user edit the trait.

Required context:

  * item.uid

  * trait.uid
    trait.content.html
    trait.content.text


HTML
============================================================

<li id="trait-{{trait.uid}}">

  <div class="section normal editable shown noscript-shown">
    {{{trait.content.html}}}
  </div>

  <div class="section editable">
    <div class="trait-controls">
      {{> small-control
            src    = "/arrow-thick-top.svg"
            title  = "move trait up"
            action = [| moveTrait("up",{{{%js item.uid}}},{{{%js trait.uid}}}); |] }}
      {{> small-control
            src    = "/arrow-thick-bottom.svg"
            title  = "move trait down"
            action = [| moveTrait("down",{{{%js item.uid}}},{{{%js trait.uid}}}); |] }}
      {{> space px=16}}
      {{> small-control
            src    = "/pencil.svg"
            title  = "edit trait"
            action = [| editTrait({{{%js item.uid}}}, {{{%js trait.uid}}},
                                  {{{%js trait.content.text}}}); |] }}
      {{> space px=16}}
      {{> small-control
            src    = "/x.svg"
            title  = "delete trait"
            action = [| deleteTrait({{{%js item.uid}}},{{{%js trait.uid}}}); |] }}
    </div>
  </div>

  <div class="section editing">
    {{! a placeholder for the editing interface created by 'editTrait' }}
  </div>

</li>


CSS
============================================================
.trait-controls {
  margin-left: -8px;
}

/* increase the clickable area */
.trait-controls a {
  display: inline-block;
  padding: 7px;
}


JS
============================================================

function moveTrait(dir, itemUid, traitUid) {
  var url = "/haskell/move/item/" + itemUid + "/trait/" + traitUid;
      traitNode = '#trait-' + traitUid;
  $.post(url, {direction: dir})
   .done(function () {
      if (dir == "up") moveNodeUp(traitNode); else moveNodeDown(traitNode);
      fadeIn(traitNode);
   });
}

function deleteTrait(itemUid, traitUid) {
  var url = "/haskell/delete/item/" + itemUid + "/trait/" + traitUid;
      traitNode = '#trait-' + traitUid;
  if (confirm("Confirm deletion?")) {
    $.post(url)
     .done(function () {
        fadeOutAndRemove(traitNode);
     });
  }
}

function submitTrait(itemUid, traitUid, original, ours) {
  var traitNode = '#trait-' + traitUid;
  $.post({
    url: "/haskell/set/item/" + itemUid + "/trait/" + traitUid,
    data: {
      original: original,
      content: ours },
    success: function (data) {
      $.magnificPopup.close();
      $(traitNode).replaceWith(data);
      switchSection(traitNode, "editable"); },
    statusCode: {
      409: function (xhr, st, err) {
        modified = xhr.responseJSON["modified"];
        merged   = xhr.responseJSON["merged"];
        showDiffPopup(ours, modified, merged, function (x) {
          submitTrait(itemUid, traitUid, modified, x) }); } }
    });
}


Note [dynamic interface]
============================================================

'makeTraitEditor' creates a textbox that appears when you try to edit a pro/con; 'makeItemNotesEditor' creates a textbox that appears when you try to edit item's notes. (Both also create some buttons/etc.)

This is rather inelegant, rather hacky, and in most places we try *not* to create any HTML dynamically, instead relying on sections (see Note [show-hide]). However, in this case we have to – Firefox has a bug that makes loading pages with lots of <textarea>s slow, and so we have to reduce the number of <textarea>s contained on each page.

See <https://github.com/aelve/guide/issues/24>.


JS
============================================================

function editTrait(itemUid, traitUid, traitMarkdown) {
  var traitNode = '#trait-' + traitUid;
  makeTraitEditor(itemUid, traitUid, traitMarkdown);
  switchSection(traitNode, "editing");
  autosizeTextarea(traitNode + " .editor-area");
  $(traitNode + " .editor-area").focus();
}

// Dynamically creates a 'View.smallMarkdownEditor'
// (but specifically for a trait).

function makeTraitEditor(itemUid, traitUid, content) {
  var traitNode = '#trait-' + traitUid;
      sectionNode = traitNode + " .section.editing";

  var template =
        '<textarea class="fullwidth editor-area" \
                   autocomplete="off" rows="5"> \
         </textarea> \
         <br> \
         <span class="text-button cancel-button"> \
           <a href="#">cancel</a> \
         </span> \
         <span style="float:right"> \
           <span class="edit-field-instruction"> \
             press Ctrl+Enter or Enter to save \
           </span> \
           <a href="/markdown" target="_blank">Markdown</a> \
         </span>';

  $(sectionNode).html(template);
  $(sectionNode + " .editor-area").text(content);
  var cancel = function () {
    $(sectionNode).html("");
    switchSection(traitNode, "editable");
  };
  $(sectionNode + " .cancel-button")[0].onclick = function () {
    cancel();
    return false;
  };
  $(sectionNode + " .editor-area")[0].onkeydown = function (event) {
    if (event.keyCode == 13 || event.keyCode == 10) {
      submitTrait(itemUid, traitUid, content, this.value);
      return false; }
    if (event.keyCode == 27) {
      cancel();
      return false; }
  };
}