Accessibility: Set iframe title attribute from child page <title>

example/html/index.html

@@ -32,6 +32,7 @@ <h2>Automagically resizing iFrame</h2>
         src="../child/frame.content.html"
         width="100%"
         scrolling="no"
+        title="iframe-resizer content examples"
       ></iframe>
     </div>
     <p id="callback"></p>

packages/child/index.js

@@ -167,10 +167,17 @@ function init() {
   startEventListeners()
   inPageLinks = setupInPageLinks()
   sendSize('init', 'Init message from host page', undefined, undefined, VERSION)
+  sendTitle()
   onReady()
   isInit = false
 }
 
+function sendTitle() {
+  if (document.title && document.title !== '') {
+    sendMsg(0, 0, 'title', document.title)
+  }
+}
+
 function checkVersion() {
   if (!version || version === '' || version === 'false') {
     advise(

packages/core/index.js

@@ -70,7 +70,7 @@ function iframeListener(event) {
       height: height + getPaddingEnds(compStyle) + getBorderEnds(compStyle),
       width: Number(data[2]),
       type: data[3],
-      version: data[4],
+      msg: data[4],
     }
   }
 
@@ -480,6 +480,12 @@ See <u>https://iframe-resizer.com/setup/#child-page-setup</> for more details.
     log(iframeId, `Version mismatch (Child: ${version} !== Parent: ${VERSION})`)
   }
 
+  function setTitle(title, iframeId) {
+    if (!settings[iframeId]?.syncTitle) return
+    settings[iframeId].iframe.title = title
+    log(iframeId, `Set title attribute to: ${title}`)
+  }
+
   function started() {
     setup = true
   }
@@ -538,14 +544,18 @@ See <u>https://iframe-resizer.com/setup/#child-page-setup</> for more details.
         findTarget(getMsgBody(9))
         break
 
+      case 'title':
+        setTitle(messageData.msg, iframeId)
+        break
+
       case 'reset':
         resetIFrame(messageData)
         break
 
       case 'init':
         resizeIFrame()
         checkSameDomain(iframeId)
-        checkVersion(messageData.version)
+        checkVersion(messageData.msg)
         started()
         on('onReady', messageData.iframe)
         break
@@ -1035,6 +1045,11 @@ The <b>sizeWidth</>, <b>sizeHeight</> and <b>autoResize</> options have been rep
       settings[iframeId].postMessageTarget = iframe.contentWindow
   }
 
+  function chkTitle(iframeId) {
+    const { title } = document.getElementById(iframeId)
+    return title === ''
+  }
+
   function processOptions(options) {
     settings[iframeId] = {
       iframe,
@@ -1043,6 +1058,7 @@ The <b>sizeWidth</>, <b>sizeHeight</> and <b>autoResize</> options have been rep
       ...defaults,
       ...checkOptions(options),
       mode: setMode(options),
+      syncTitle: chkTitle(iframeId),
     }
 
     setDirection()