Can't use multiple sourceID's with an XML source data

Can you describe a little more clearly what you think is wrong? Given that $item_ID_xpath only supports a single value at once, overriding prepareKey is precisely the right thing to do to populate a multi-column key - if that is working for you, then all is as it should be.

No further response.

I think my problem is similar to the one posted here - at least, my issue title matches.

My source rows key is a combination of 3 fields: Date, StartTime and BroadcastID. Here is an example of my source xml data:

<event>
  <Date>2013/08/31</Date>
  <StartTime>16:40</StartTime>
  <Duration>00:50:00</Duration>
  <BroadcastID>0238435</BroadcastID>
  <ProgrammeTitle>The Young And The Restless</ProgrammeTitle>
</event>

My problem is that although there are over 900 events in the xml, Migrate is only picking up 27 of them. This is because I've set $item_ID_xpath = 'Date'; when creating a new MigrateItemsXML object, and there are 27 unique days in the xml.

I've tried using prepareKey() as suggested ('sourceid' is set up when creating the MigrateSQLMap object):

  public function prepareKey($source_key, $row) {
    $key['sourceid'] = $row->xml->Date . ' ' . $row->xml->StartTime . ' ' . $row->xml->BroadcastID;
    return $key;
  }

I expected that using prepareKey() to set a unique key per row would allow Migrate to pick up all events, but it's still only picking up one event per Date. Am I right to pick prepareKey() for this, or should I be looking somewhere else? I previously had this logic working fine with a csv source file - my source has recently changed to xml.

The solution was to override the way that Migrate accesses a unique row from the XML. Default behaviour is to access it using a single field.

I overrode MigrateItemsXML like so:

class MigrateItemsScheduleXML extends MigrateItemsXML {
  public function __construct($xml_url, $item_xpath='item', $itemID_xpath='id') {
    parent::__construct($xml_url, $item_xpath, $itemID_xpath);
  }

  /**
   * Get the item ID from the itemXML based on itemIDXpath.
   *
   * @return string
   */
  protected function getItemID($itemXML) {
    $itemID = $this->getElementValue($itemXML, 'Date');
    $itemID .= ' ' . $this->getElementValue($itemXML, 'StartTime');
    $itemID .= ' ' . $this->getElementValue($itemXML, 'BroadcastID');
    return $itemID;
  }
}

and then implemented MigrateItemsScheduleXML like so:

    $item_xpath = 'event';  // relative to document
    $item_ID_xpath = 'Date';         // relative to item_xpath and gets assembled
                                         // into full path /producers/producer/sourceid

    $items_class = new MigrateItemsScheduleXML($items_url, $item_xpath, $item_ID_xpath);
    $this->source = new MigrateSourceMultiItems($items_class, $fields);

Thanks to mikeryan's comment at #2 on #1376520: XML with 'concatenated' primary key for pointing me in the right direction.

What's weird is that I can completely discard prepareKey() since that logic is now handled in getItemID() - I'm not sure that this is consistent, since I used prepareKey() to set up my source key when using a csv file, but now I've got to override MigrateItemsXML and getItemID() to do the same logic when using an xml file. That's not obvious.

Fix typo

No open question here.