(PHP 5, PHP 7, PHP 8)
DOMText::isWhitespaceInElementContent — このテキストノードが空白を含むかどうかを示す
このテキストノードが空白のみを含む（あるいは空である）かどうかを示します。 このテキストノードが要素の内容に空白を含むかどうかは、 ドキュメントの読み込み時に決定されます。
この関数にはパラメータはありません。
if you have an xml element such as <name>Foo Bar</name> (note the space), isWhitespaceInElementContent will return false.
However it will return true for <name><name> or <name/>
so, that function can be used to determine if the element has a text content or notTo add to `permidion at yahoo dot com''s comment:
Quite true. According to DOM Level 3 Core, the `isWhitespaceInElementContent()' method indicates, whether the node contains `whitespace in element content' (or `element content whitespace' according to the newer spec), see [1].
Btw, it seems the `isWhitespaceInElementContent()' method was replaced with the `isElementContentWhitespace' attribute in the current W3C recommendation, see [2].
I have the feeling, though, it would be more precise with the word `only' added, like: `... indicates, whether the node contains *only* element content whitespace.' This would better correspond with the fact the result is false, when there are any non-whitespace characters present (in addition to the whitespace ones), as already noted.
[1] (please concatenate the following two lines)
http://www.w3.org/TR/2003/WD-DOM-Level-3-Core-20030226/DOM3-Core.html
#core-Text3-isWhitespaceInElementContent
[2] (please concatenate the following two lines)
http://www.w3.org/TR/DOM-Level-3-Core/core.html
#Text3-isElementContentWhitespace