在CKEditor中选择光标前的单词

Question

我正在处理自动填充插件，我的要求是在按空格键的同时选择光标前的单词，以便我可以获取所选文本并填充或插入新文本。

E.g。在“ck”之后按空格时，我用“CKEditor”替换“ck”。

我所做的是，在按空格键时，我将光标前的单词作为键，如果键是“ck”，则用“CKEditor”替换它，选择带有范围的“ck”并插入新单词“CKEditor”

if (e.data.keyCode == 32) { 

    var s = editor.getSelection();  
    var cursor = s._.cache.nativeSel.anchorOffset;
    var data = s._.cache.nativeSel.focusNode.data;
    var node = s._.cache.nativeSel.focusNode;
    var selection = editor.getSelection();
    data = data.substring(0,cursor)
    var startIndex = data.lastIndexOf(" ");
    if (startIndex==-1) {
        startIndex=0;
    } else {
        startIndex=startIndex+1;
    }
    var key = data.substring(startIndex,data.length);
    // HERE KEY IS THE WORD BEFORE CURSOR, THERE IS NO ISSUE IN IT. 
    key = key.trim();
    if (key.trim() == 'ck') {
        var ranges = [];
        var range, text, index;
        console.log(editor.getSelection().getStartElement());
        var text = getTextNodes( editor.getSelection().getStartElement() ,key );
        range = editor.createRange();
        range.setStart( text, cursor - (key.length));
        range.setEnd( text, cursor);  
        ranges.push( range );
        selection.selectRanges( ranges );
        editor.insertHtml('CKEditor'); 
    }


// GETTING NODE OF THE KEY

function getTextNodes( element,key ) {
    var children = element.getChildren();
    var child;
    for ( var i = children.count(); i--; ) {
        child = children.getItem( i );
        if ( child.type == CKEDITOR.NODE_ELEMENT )
            getTextNodes( child );
        else if ( child.type == CKEDITOR.NODE_TEXT ) {
           if (child.$.data.indexOf(key)!=-1) {
               var text = child;
               return child;
        }
   }
}

它工作正常99％，但如果“ck”是新行的第一个单词则失败。