Patch CodeMirror to trigger custom events on copy/cut to be used with a local buffer

CodeMirror.5.36.0.copy.cut.js

// there are 2 patches, also see: https://github.com/codemirror/CodeMirror/issues/5594
// line 8703  
function onCopyCut(e) {
    if (signalDOMEvent(cm, e)) { return }
    if (cm.somethingSelected()) {
      setLastCopied({lineWise: false, text: cm.getSelections()})
      if (e.type == "cut") { cm.replaceSelection("", null, "cut") }
    } else if (!cm.options.lineWiseCopyCut) {
      return
    } else {
      var ranges = copyableRanges(cm)
      setLastCopied({lineWise: true, text: ranges.text})
      if (e.type == "cut") {
        cm.operation(function () {
          cm.setSelections(ranges.ranges, 0, sel_dontScroll)
          cm.replaceSelection("", null, "cut")
        })
      }
    }
    /* -----------
     * |**patch**|
     * -----------
     * trigger custom event 'cut' or 'copy', just add a handler on a parent and
     * look for "event.detail.data" or "event.detail.target", 
     * see: https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Creating_and_triggering_events,
     * https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent
     */
    var event = new CustomEvent(e.type, {detail: {text: cm.getSelections(), target: cm.display.wrapper}, bubbles: true, cancelable: true});
    cm.display.wrapper.dispatchEvent(event);
    /* end */
    if (e.clipboardData) {
      e.clipboardData.clearData()
      var content = lastCopied.text.join("\n")
      // iOS exposes the clipboard API, but seems to discard content inserted into it
      e.clipboardData.setData("Text", content)
      if (e.clipboardData.getData("Text") == content) {
        e.preventDefault()
        return
      }
    }
    // Old-fashioned briefly-focus-a-textarea hack
    var kludge = hiddenTextarea(), te = kludge.firstChild
    cm.display.lineSpace.insertBefore(kludge, cm.display.lineSpace.firstChild)
    te.value = lastCopied.text.join("\n")
    var hadFocus = document.activeElement
    selectInput(te)
    setTimeout(function () {
      cm.display.lineSpace.removeChild(kludge)
      hadFocus.focus()
      if (hadFocus == div) { input.showPrimarySelection() }
    }, 50)
  }

// after previous replacement look at line 9222 
  function prepareCopyCut(e) {
    if (signalDOMEvent(cm, e)) { return }
    if (cm.somethingSelected()) {
      setLastCopied({lineWise: false, text: cm.getSelections()})
    } else if (!cm.options.lineWiseCopyCut) {
      return
    } else {
      var ranges = copyableRanges(cm)
      setLastCopied({lineWise: true, text: ranges.text})
      if (e.type == "cut") {
        cm.setSelections(ranges.ranges, null, sel_dontScroll)
      } else {
        input.prevInput = ""
        te.value = ranges.text.join("\n")
        selectInput(te)
      }
    }
    if (e.type == "cut") { cm.state.cutIncoming = true }
    /* -----------
     * |**patch**|
     * -----------
     * trigger custom event 'cut' or 'copy', just add a handler on a parent and
     * look for "event.detail.data" or "event.detail.target", 
     * see: https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Creating_and_triggering_events,
     * https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent
     */
    var event = new CustomEvent(e.type, {detail: {text: cm.getSelections(), target: te}, bubbles: true, cancelable: true});
    te.parentNode.dispatchEvent(event);
    /* end */
  }

jQuery v3.1.1 has problems with event.originalEvent.detail, use addEventlistener or patch with jQuery trigger().