How to Edit an XML File in PHP

Edit data inside an XML document using the DOMDocument class in PHP.

Use PHP (Hypertext Preprocessor) to manage, edit and control other files of different formats on your server. Extensible Markup Language (XML) is a programming language used to transport and store data. PHP was created to use with the SQL programming language, which also helps with the storage of data. This makes PHP optimum to work with the XML programming language. PHP has a predefined class called DOMDocument that is used to work with XML documents. Use the DOMDocument class to edit XML files on your server.

Instructions

1. Open a new document in a text-editing program like Notepad or a web-authoring application such as Dreamweaver.

2. Use the "DOMDocument" class in PHP to load the XML document that you want to edit. You do this by creating a new class instance in the PHP coding. It looks something like this:

   "<?php

   $xml_Document= new DOMDocument('1.0', 'utf-8');

   $xml_Document->formatOutput = true;

   $xml_Document->preserveWhiteSpace = false;

   $xml_Document->load('example.xml');"

   Change the "example.xml" to the name of the XML document that you want to edit. Remove the quotation marks from the first and last line of the code.

3. Type in the code to load the "table" from the XML document. Load the table as an element by using the table name. For instance, if you have a "Contacts" table with column headings of "Name," "Address," "City," "State," "Zip Code" and "Telephone Number," you load "Contacts" before loading the individual columns. Load the table element with the PHP code to edit.

   "$element = $xml->getElementsByTagName('contact')->contact(0);"

   Change "contact" to the name of your table.

4. Load the child elements with the PHP code. These child elements are the names of the individual columns inside of the table.

   "$name = $element->getElementsByTagName('name')->contact(0);

   $address = $element->getElementsByTagName('address')->contact(0);

   $city = $element->getElementsByTagName('city')->contact(0);

   $state = $element->getElementsByTagName('state')->contact(0);

   $zip = $element->getElementsByTagName('zip code')->contact(0);

   $phone = $element->getElementsByTagName('telephone')->contact(0);"

   The coding represents the columns in the "Contacts" table example used above. Change the values to represent the columns in your XML document.

5. Use PHP code to edit the values in the rows of the table specified above. Specify the row that you want to change first by adding the value to the variable. Then decide which column of information that corresponds with that row you want to change. For instance, say you have a contact with the name "Jon Doe" in your "Contacts" table who has changed his phone number. To change the phone number in the XML document, pull two pieces of information that matche the "Jon Doe" record so that the code knows what row you are referring to and then change the information. The coding will look something like this:

   "$name->nodeValue = 'Jon Doe';

   $state->nodeValue = 'NY';"

   Now that you have specified what row to change, set a new variable to change the information you need to change.

   "$newPhone = $xml->createElement('telephone' 213-555-5555);

   $element->replaceChild($name, $name);

   $element->replaceChild($state,$state);

   $element->replaceChild($newPhone, $phone);

   ?>"

   As you can see, you replace the "Name" and "State" information for "Jon Doe" to the old data that you loaded from the XML document. You didn't change that information at all. But for the phone number, you changed that to the new phone number specified earlier. Use this as a road map for editing the rows inside of your XML document, using the right column names and the information that you want to change.

6. Save the PHP document and load it to your web server in the same folder as the XML document you want to edit. Run the PHP document by typing in its web address in an Internet browser and hitting "Enter" on your keyboard.

References

• PHP 4 Every 1: Edit XML
• PHP: The DOMDocument Class
• The Free Dictionary: PHP