Get variables from several interrelated functions in PHP - php

Question

I'm trying to get variables from several interrelated functions during XML parsing and put them into arrays. The code is:
function readChapters($reader) {
while($reader->read()) {
if( /* condition here */ ) {
$chapter = readValue($reader);
}
if( /* condition here */ ) {
readModules($reader);
}
if( /* condition here */ ) {
return;
}
}
}
function readModules($reader) {
while($reader->read()) {
if( /* condition here */ ) {
readModule($reader);
}
if( /* condition here */ ) {
return($reader);
}
}
}
function readModule($reader) {
while($reader->read()) {
if( /* condition here */ ) {
$topic = readValue($reader);
}
if( /* condition here */ ) {
$description = readValue($reader);
}
}
}
function readValue($reader) {
while($reader->read()) {
if( /* condition here */ ) {
return $reader->readInnerXML();
}
}
}
$reader = new XMLReader();
$reader->open('example.xml');
$current = 0;
$topics_list = array();
$chapterName = ""; // want to add $chapter
$topicName = ""; // want to add $topic
$descriptionText = ""; // want to add $description
while($reader->read()) {
if(// condition here) {
readChapters($reader);
}
$topics_list[$current] = array();
$topics_list[$current]['chapter'] = $chapterName;
$topics_list[$current]['topic'] = $topicName;
$topics_list[$current]['description'] = $descriptionText;
}
$reader->close();
print_r($topics_list);
Problem: How to get $chapter, $topic, $description variables from outside of these functions in order to put them into arrays? Thanks in advance.
Update: The XML document structure is here, and the expected structure of Array():
Array (
[0] => Array (
[chapter] => Chapter_name1
[topic] => Topic_name1
[description] => Content_of_the_topic1
)
[1] => Array (
[chapter] => Chapter_name1
[topic] => Topic_name2
[description] => Content_of_the_topic2
)
[2] => Array (
[chapter] => Chapter_name2
[topic] => Topic_name2
[description] => Content_of_the_topic2
)
.....
)

Answer 1

You're essentially using a set of function to build a data structure using data from an XML object. That means that each function should return the data structure it's named for: readChapters() should return a chapter structure (and should probably be named readChapter(), since I think it's only reading one chapter, correct?), and so on. I don't know what your XML looks like or what your desired data structure looks like, but you'll want something like this:
function readChapter($reader) {
$chapter = array();
while (// condition) {
if (// something)
$chapter['chapter'] = readValue($reader);
elseif (// something else)
$chapter['topic'] = readValue($reader);
// etc
}
return $chapter;
}
Then in your main loop below, you can have this:
while ($reader->read()) {
if (// condition here) {
$topics_list[] = readChapter($reader);
}
}
Hope that gets you closer to something you can build!