read xml content and add some numbers with php - php

Question

I have an xml file but through php I would like to make some changes only for some products (each item has its own id.
Let me explain better on some products I would like to add the shipping cost with the price and at the item use grid put from 1 to 0.
<Products>
<Product>
<sku>35</sku>
<sku_manufacturer>test sku</sku_manufacturer>
<manufacturer>test manufacturer</manufacturer>
<ean>800000000000</ean>
<title><![CDATA[title test]]></title>
<description><![CDATA[description</description>
<product_price_vat_inc>8.08</product_price_vat_inc>
<shipping_price_vat_inc>4.99</shipping_price_vat_inc>
<quantity>2842</quantity>
<brand><![CDATA[Finder]]></brand>
<merchant_category><![CDATA[Home/test category]]></merchant_category>
<product_url><![CDATA[https://www.example.com]]></product_url>
<image_1><![CDATA[https://www.example.com]]></image_1>
<image_2><![CDATA[]]></image_2>
<image_3><![CDATA[]]></image_3>
<image_4><![CDATA[]]></image_4>
<image_5><![CDATA[]]></image_5>
<retail_price_vat_inc/>
<product_vat_rate>22</product_vat_rate>
<shipping_vat_rate>22</shipping_vat_rate>
<manufacturer_pdf/>
<ParentSKU/>
<parent_title/>
<Cross_Sell_Sku/>
<ManufacturerWarrantyTime/>
<use_grid>1</use_grid>
<carrier>DHL</carrier>
<shipping_time>2#3</shipping_time>
<carrier_grid_1>DHL</carrier_grid_1>
<shipping_time_carrier_grid_1>2#3</shipping_time_carrier_grid_1>
<carrier_grid_2/>
<shipping_time_carrier_grid_2/>
<carrier_grid_3/>
<shipping_time_carrier_grid_3/>
<carrier_grid_4/>
<shipping_time_carrier_grid_4/>
<carrier_grid_5/>
<shipping_time_carrier_grid_5/>
<DisplayWeight>0.050000</DisplayWeight>
<free_return/>
<min_quantity>1</min_quantity>
<increment>1</increment>
<sales>0</sales>
<eco_participation>0</eco_participation>
<shipping_price_supplement_vat_inc>0</shipping_price_supplement_vat_inc>
<Unit_count>-1.000000</Unit_count>
<Unit_count_type/>
</Product>
</Products>

Answer 1

You XML is a little large so let's strip it down for the example:
$xmlString = <<<'XML'
<Products>
<Product>
<sku>35</sku>
<title><![CDATA[title test]]></title>
<use_grid>1</use_grid>
</Product>
<Product>
<sku>42</sku>
<title><![CDATA[title test two]]></title>
<use_grid>1</use_grid>
</Product>
</Products>
XML;
DOM is a standard API for XML manipulation. PHP supports it and Xpath expressions for fetching nodes.
$document = new DOMDocument('1.0', "UTF-8");
// $document->load($xmlFile);
$document->loadXML($xmlString);
// $xpath for fetching node using expressions
$xpath = new DOMXpath($document);
// iterate "Product" nodes with a specific "sku" child
foreach ($xpath->evaluate('//Product[sku="35"]') as $product) {
// output sku and title for validation
var_dump(
$xpath->evaluate('string(sku)', $product),
$xpath->evaluate('string(title)', $product)
);
// iterate the "use_grid" child elements
foreach ($xpath->evaluate('./use_grid', $product) as $useGrid) {
// output current value
var_dump(
$useGrid->textContent
);
// change it
$useGrid->textContent = "0";
}
}
echo "\n\n", $document->saveXML();
Output:
string(2) "35"
string(10) "title test"
string(1) "1"
<?xml version="1.0"?>
<Products>
<Product>
<sku>35</sku>
<title><![CDATA[title test]]></title>
<use_grid>0</use_grid>
</Product>
<Product>
<sku>42</sku>
<title><![CDATA[title test two]]></title>
<use_grid>1</use_grid>
</Product>
</Products>
Xpath::evaluate()
Xpath::evaluate() fetches nodes using an Xpath expression. The result type depends on the expression. A location path like //Product[sku="35"] will return a list of nodes (DOMNodeList). However Xpath functions inside the can return a scalar value - string(sku) will return the text content of the first sku child node as a string or an empty string.
DOMNode::$textContent
Reading $node->textContent will return all the text inside a node - including inside descendant elements.
Writing it replaces the content while taking care of the escaping.