Retrieving data from siblings to node that match - php

Question

I'm iterating through a xml doc with SimpleXML. I have an array ($ids) with id's and I'm checking whether there's a match or not in the XML (Worksheet/Table/Row/Cell/Data). If it's a match I want to be able to get to the data from the following two siblings, but I can't figure out how.
from the php:
// $ids <---- array('8', '53', '38')
foreach ($thePositions->Worksheet->Table->Row as $row) {
if($row->Cell->Data == true) {
for ($i = 0; $i < count($ids); $i++) {
foreach($row->Cell->Data as $data) {
if ($data == $ids[$i]) {
echo 'match!';
/*
Tried $siblings = $data->xpath('preceding-sibling::* | following-sibling::*');
but doesn't seem to work in this case.
*/
}
}
}
}
}
the xml:
<?xml version="1.0"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
xmlns:o="urn:schemas-microsoft-com:office:office"
xmlns:x="urn:schemas-microsoft-com:office:excel"
xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
xmlns:html="http://www.w3.org/TR/REC-html40">
<DocumentProperties xmlns="urn:schemas-microsoft-com:office:office">
<LastAuthor>Herpa Derp </LastAuthor>
<Created>2012-09-25T13:44:01Z</Created>
<LastSaved>2012-09-25T13:48:24Z</LastSaved>
<Version>14.0</Version>
</DocumentProperties>
<OfficeDocumentSettings xmlns="urn:schemas-microsoft-com:office:office">
<AllowPNG/>
</OfficeDocumentSettings>
<ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">
<WindowHeight>14060</WindowHeight>
<WindowWidth>25040</WindowWidth>
<WindowTopX>25540</WindowTopX>
<WindowTopY>4100</WindowTopY>
<Date1904/>
<ProtectStructure>False</ProtectStructure>
<ProtectWindows>False</ProtectWindows>
</ExcelWorkbook>
<Styles>
<Style ss:ID="Default" ss:Name="Normal">
<Alignment ss:Vertical="Bottom"/>
<Borders/>
<Font ss:FontName="Calibri" x:Family="Swiss" ss:Size="12" ss:Color="#000000"/>
<Interior/>
<NumberFormat/>
<Protection/>
</Style>
<Style ss:ID="s62">
<Font ss:FontName="Courier" ss:Color="#000000"/>
</Style>
</Styles>
<Worksheet ss:Name="Workbook1.csv">
<Table ss:ExpandedColumnCount="5" ss:ExpandedRowCount="79" x:FullColumns="1"
x:FullRows="1" ss:DefaultColumnWidth="65" ss:DefaultRowHeight="15">
<Column ss:Index="2" ss:AutoFitWidth="0" ss:Width="43"/>
<Column ss:AutoFitWidth="0" ss:Width="113"/>
<Column ss:Index="5" ss:AutoFitWidth="0" ss:Width="220"/>
<Row ss:Index="6">
<Cell ss:Index="3" ss:StyleID="s62"/>
</Row>
<Row>
<Cell ss:Index="3" ss:StyleID="s62"/>
</Row>
<Row>
<Cell ss:Index="3" ss:StyleID="s62"/>
</Row>
<Row>
<Cell ss:Index="2"><Data ss:Type="String">id</Data></Cell>
<Cell ss:StyleID="s62"><Data ss:Type="String">latitude</Data></Cell>
<Cell><Data ss:Type="String">longitude</Data></Cell>
</Row>
<Row>
<Cell ss:Index="2"><Data ss:Type="Number">8</Data></Cell>
<Cell ss:StyleID="s62"><Data ss:Type="Number">57.4999</Data></Cell> // to be saved to $latutude
<Cell><Data ss:Type="Number">15.8280</Data></Cell> // to be saved to $longitude
</Row>
<Row>
<Cell ss:Index="2"><Data ss:Type="Number">38</Data></Cell>
<Cell><Data ss:Type="Number">56.5659</Data></Cell>
<Cell><Data ss:Type="Number">16.1380</Data></Cell>
</Row>

Answer 1

The reason asking for siblings isn't working is that the <Data> elements aren't siblings; they're more like cousins - children of adjacent <Cell> elements.
For the same reason, you shouldn't be using foreach($row->Cell->Data as $data), as this is equivalent to foreach($row->Cell[0]->Data as $data), i.e. look at all <Data> children of the first <Cell> node. Since there will only ever be one <Data> element in a <Cell>, you might as well just write $data = $row->Cell[0]->Data - which in this case is fine, because the values you're looking for are at the beginning of rows.
What you actually need to do is loop over the <Cell>s: foreach($row->Cell as $cell) { $data = $cell->Data; /* ... */ }
You then have a couple of options for finding the adjacent cells, including XPath. A more "PHP-ish" way would be to use array indexes (siblings are indexed numerically in SimpleXML loop/array access):
foreach($row->Cell as $cell_index => $cell)
{
$data = $cell->Data;
if ($data == $ids[$i])
{
// Tip: always cast SimpleXML objects to string when you're done with their magic XMLiness
$latitudes[$i] = (string)$row->Cell[ $cell_index + 1 ]->Data;
$longitudes[$i] = (string)$row->Cell[ $cell_index + 2 ]->Data;
}
}
Alternatively, you could rely on your IDs always being in the first column, and the lat and long in the next two (this is a spreadsheet, after all!) and avoid the inner loop altogether:
if ( $row->Cell[0]->Data == $ids[$i] )
{
$latitudes[$i] = (string)$row->Cell[1]->Data;
$longitudes[$i] = (string)$row->Cell[2]->Data;
}

Answer 2

It looks like in case of this XML, cells are always in same order so it can be done as follows:
$ids = array('8', '53', '38');
foreach ($xml->Worksheet->Table->Row as $row) {
$children = $row->children();
if (count($children) == 3 && in_array(((string) $children[0]->Data), $ids)) {
echo 'lat: ' . $children[1]->Data . ' lng: ' . $children[2]->Data . "\n";
}
}

Answer 3

You can do it entirely in XPath, without any loops, like:
//Row[Cell/Data[. = '8' or . = '53' or . = '38']]/following-sibling::*[position() <= 2]
That search all rows with the id in any data element and then takes the next two siblings.
Or
//Row[Cell[1]/Data[. = '8' or . = '53' or . = '38']]/following-sibling::*[position() <= 2]
if it is sure that the id is always in the first cell. (which also prevents errors due to an id being the same as a longitude/langitude)
Or
//Row[Cell[#ss:Index = "2"]/Data[. = '8' or . = '53' or . = '38']]/following-sibling::*[position() <= 2]
if the id is in the cell with index 2.
But in all cases, you need to initialize the namespaces correctly

Answer 4

An alternative approach if you have lots of IDs to match is to create a "hash" of all the rows based on their ID, and then look into that hash rather than looping through searching for matches.
// Initialise an empty array to use as the hash
$rows_by_id = array();
// Loop over all the rows in the spreadsheet
foreach ($thePositions->Worksheet->Table->Row as $row) {
// Skip rows with less than 3 cells
if ( count($row->Cell) < 3 ) {
continue;
}
// Take the ID from the first cell on the row
$id = (string)$row->Cell[0]->Data;
// Add this row to the hash, identified by it's ID
$rows_by_id[$id] = array(
'latitude' => (string)$row->Cell[1]->Data,
'longitude' => (string)$row->Cell[2]->Data
);
// Or if your IDs are not unique, and you want all matches:
// $rows_by_id[$id][] = array( ... )
}
foreach ( $ids as $required_id ) {
// Retrieve the results from the hash
if ( isset($rows_by_id[$required_id]) ) {
$matched_row = $rows_by_id[$required_id];
echo "ID $required_id has latitude {$matched_row['latitude']} and longitude {$matched_row['longitude']}.\n";
}
else {
echo "ID $required_id was not matched. :(\n";
}
// If you have non-unique matches, you'll need something like this:
// $all_matched_rows = $rows_by_id[$required_id]; ... foreach ( $all_matched_rows as $matched_row )
}