Stream.xml.each(pathStr){action}

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Stream.xml.each(pathStr){ action(s) }

This operator locates the xml object for each object at the pathStr (within the XML), generating a l. The .each(pathStr) invokes the action block with the xml item bound in turn to each book element. On completion, it restores the XML object to its previous state.

Consider a note "Source note" with this $Text:

<shelf>
	<book price="9.95">War and Peace</book>
	<book price="4.95">No et Moi</book>
	<audio price="14.95">Born To Run</audio>
</shelf>

Example usage of path:

$MyList("test") = "";
$Text("Source note").xml.each("/shelf/book"){
	$MyList("test2")+=xml["book"]+"\n";
};

which sets $MyList of note "test" to a list of children of the <shelf> element that are <book> elements. "War and Peace;No et Moi".

$MyList("test2") = "";
$Text("Source note").xml.each("/shelf/book"){
	$MyList("test2")+=xml["book[2]"]+"\n";
};

which sets $MyList of note "test" to the value of child element of the <shelf> element that represents the second book, "No et Moi". Other iterated elements return a blank. See 'Notes' below.

$MyList("test2") = "";
$Text("Source note").xml.each("/shelf/book"){
	$MyList("test2")+=xml["book@price"]+"\n";
};

witch sets $MyList of note "test" to a list of the price attribute of each book element, "9.95;4.95".

Notes:

• Acceptable path content is a subset of the XPath standard (see https://www.w3.org/TR/2017/REC-xpath-31-20170321/).
• To accord with standard XML and XPath usage, the first child of an XML node is child [1], not [0].
• XML attributes are not related to Tinderbox attributes.

Consider this source stream:

<shelf>
<book price="9.95">War and Peace</book>
<book price="4.95">No et Moi</book>
<audio price="14.95">Born To Run</book>
</shelf>

Examples

Stream.xml.each("/shelf/book") {action} 

returns every 'book' object in the 'shelf' object and iterates over them, i.e. for each (path-matched) item it invokes the action block with the xml item bound in turn to each book element. In the example above this means the action is run 3 times, once for each of the 3 <book> elements under <shelf>.

Inside the action clause, action code can refer to the value of the iterated item as elementName[], book[]. Any attribute of that item can be addressed as elementName[@attribute] book[@price], 'i.e. here the 'price' attribute of the XML object in focus.

On completion, it restores the xml object to its previous state.