WordPress: using PHP Libraries, Web Service Integrations & Platform Migrations

GD

GD is probably the most popular image-manipulation PHP library and usually comes compiled with default installations of PHP. GD tends to be a little bit faster than Imagick when dealing with larger images and it is generally less of a server resource hog. GD is a great tool and can get you where you need to go most of the time, but Imagick has more features and functionality.

Imagick

One of the most powerful image-manipulation tools and our personal favorite—though we wish someone would update its website to use WordPress—Imagick can be used to manipulate image files programmatically in just about any way you can imagine. You can install Imagick on your server and run it through the command line via the shell_exec() or exec() PHP functions, or you can use the Imagick PHP library as a wrapper for the underlying software. The Imagick library is not bundled with PHP by default and you must install it separately along with the Imagick software itself.

Justin Sternberg made some really easy-to-use methods using Imagick for overlaying any text on any image and then saving the separate image as an attachment against a WordPress post. This can be very useful if you require all the images on your web application to be watermarked with your URL, so if anybody hijacks your images, at least they have your web address embedded into them. Check out Justin’s code at WordPress-Image-Watermark.

Zebra_Image

Zebra_Image is a super-lightweight and easy-to-use PHP library for image manipulation. This is a great alternative to Imagick, if Imagick is overkill, you can’t install Imagick on your web server, or you only need to perform some basic image-manipulation tasks like resizing, cropping, rotating, flipping, and/or sharpening images. This single-file PHP library requires only the GD extension, which usually comes precompiled with PHP.

Imagine

Somewhere between Imagick and Zebra_Image is probably Imagine. This object-oriented PHP library is very powerful, and you can use it to do almost any kind of image manipulation. Like Zebra_Image, Imagine is also a GD-based PHP library.

Dynamic Dummy Image Generator

The Dynamic Dummy Image Generator isn’t a PHP library, but it’s a great little tool that we wanted to mention that can help your WordPress website development efforts. You know when your client never provided you with the images they promised you three weeks ago? Using Dummy Image, you can dynamically create any sized images from a URL.

Snappy

Now this is cool! With Snappy, you can automatically create an image and/or a PDF from any URL or HTML page. Think of all the cool things you can do by autogenerating an image of any website you want.

Snappy

We mentioned Snappy earlier, but we wanted to reiterate how cool and easy it is to generate PDFs of a web page via a provided URL or HTML. You can even generate a multiple-page PDF document by passing in multiple URLs. Want a detailed PDF document of your entire website? Just loop all of your pages and pass them into Snappy!

Snappy uses two popular open source HTML-to-PDF and HTML-to-image command-line tools: wkhtmltopdf and wkhtmltoimage. You can download and install the necessary binary files and easily install them on your server with Composer: A Dependency Manager for PHP.

FPDF

The F in FPDF stands for “free”! This is a great lightweight alternative to PDFlib if you are not generating too many PDF documents and they are not too complex. You can use FPDF to generate dynamic PDF documents with just PHP: it does not depend on other PHP libraries except for Zlib to enable compression and GD for GIF support, which both usually come precompiled with PHP. Some of the main functions of FDPF include the following:

__construct

Constructor

AcceptPageBreak

Accept or not automatic page break

AddFont

Add a new font

AddLink

Create an internal link

AddPage

Add a new page

AliasNbPages

Define an alias for number of pages

Cell

Print a cell

Close

Terminate the document

Error

Fatal error

Footer

Page footer

GetPageHeight

Get current page height

GetPageWidth

Get current page width

GetStringWidth

Compute string length

GetX

Get current x position

GetY

Get current y position

Header

Page header

Image

Output an image

Line

Draw a line

Link

Put a link

Ln

Line break

MultiCell

Print text with line breaks

Output

Save or send the document

PageNo

Page number

Rect

Draw a rectangle

SetAuthor

Set the document author

SetAutoPageBreak

Set the automatic page-breaking mode

SetCompression

Turn compression on or off

SetCreator

Set document creator

SetDisplayMode

Set display mode

SetDrawColor

Set drawing color

SetFillColor

Set filling color

SetFont

Set font

SetFontSize

Set font size

SetKeywords

Associate keywords with document

SetLeftMargin

Set left margin

SetLineWidth

Set line width

SetLink

Set internal link destination

SetMargins

Set margins

SetRightMargin

Set right margin

SetSubject

Set document subject

SetTextColor

Set text color

SetTitle

Set document title

SetTopMargin

Set top margin

SetX

Set current x position

SetXY

Set current x and y positions

SetY

Set current y position and optionally reset x

Text

Print a string

Write

Print flowing text

Other PDF-generation PHP libraries

Depending on your specific needs you may want to do a Google search for some of these and look them over in more detail:

• wkhtmltopdf

• mPDF

• Dompdf

• TCPDF

• HTML2PdF

MaxMind GeoIP

MaxMind GeoIP gets data from a user’s IP address, such as their location and internet provider. MaxMind is a great service because it has a very extensive API and a free downloadable database.

You can download the PHP library with all of the functionality from the MaxMind website. To utilize its API, download and install the code from GitHub.

Geocoder PHP

Geocoder PHP is a PHP library that will assist you in building geo-aware web and mobile applications. Unlike MaxMind, which is its own geolocation provider, Geocoder PHP allows you to choose from multiple geolocation providers, including MaxMind. This PHP library makes calling and fetching geolocation data from various geolocation providers streamlined and consistent. To use the Geocoder PHP library, you need to choose a provider and an HTTP client/adapter. The following providers are currently available to this PHP library, and you can add your own if need be:

• Algolia Places

• ArcGIS Online

• Bing Maps

• FreeGeoIp

• Geocode Earth

• GeoIP

• GeoIP2

• Geonames

• GeoPlugin

• Google Maps

• Google Maps Places

• GraphHopper

• Here

• HostIp

• IpInfo

• IpInfoDB

• ipstack

• LocationIQ

• Mapbox

• MapQuest

• MaxMind

• MaxMind Binary

• Nominatim

• OpenCage

• Pelias

• Photon

• PickPoint

• TomTom

• Yandex

Web-hosting geolocation

Some web hosts have geotargeting services baked into their platforms to offer you geolocation information like a site visitor’s continent, country, state/region, or city. You can use this data to display different content to visitors based on their location.

For instance, on top of WP Engine’s hosting services, it has an additional geolocation service that integrates with its platform’s custom WordPress caching system via a custom WordPress plugin. It stores cached visitor information in buckets that can be accessed via preset PHP variables and WordPress shortcodes. This is probably one of the fastest ways to integrate geolocation data with your website, but you must already be hosted with WP Engine.

Compressing individual files into an archive

Here is some basic code for adding files to a ZIP archive that you create one file at a time. As you can imagine, you could write some code to loop through any files you want, adding them to your new ZIP file however you want:

<?php

// First create a ZipArchive Instance
$zip = new ZipArchive();

// Use the open() method to create a zip file on the server
$zip->open( 'compressed-dir-path/messenlehner-kids.zip', ZipArchive::CREATE );

// Use the addFile() method to add a file to your zip
$zip->addFile( 'some-dir-path/index.html', 'index.html' );

// You can also add files to subdirectories within the zip
$zip->addFile( 'some-dir-path/dalya.png', 'images/dalya.png' );
$zip->addFile( 'some-dir-path/brian.png', 'images/brian.png' );
$zip->addFile( 'some-dir-path/nina.mp4', 'videos/nina.png' );

// You can also change a file name while you are adding it to the zip
$zip->addFile( 'some-dir-path/CWM.png', 'images/cam.png' );
$zip->addFile( 'some-dir-path/babyA.png', 'images/aksel.png' );

// Call the close() method to finish and save your new zip
$zip->close();

?>

Compressing multiple files into an archive

ZipArchive has functions for retrieving various files from provided directory paths so you can add files to your ZIP archive file in bulk instead of one by one:

addGlob()

This method allows you to identify files of defined file types.

addPattern()-

This method allows you to use regular expressions to identify files in a directory based on any pattern in their filename.

Following is an example using both the addGlob() and addPattern() methods to add all .png and .jpg images and .mp4 videos from provided directories into a ZIP file:

<?php

// First create a ZipArchive Instance
$zip = new ZipArchive();

// Use the open() method to create a zip file on the server
$zip->open( 'compressed-dir-path/messenlehner-kids.zip', ZipArchive::CREATE );

// Set options array to add the directory 'videos' to the zip file
$options = array( 'add_path' => 'videos/', 'remove_all_path' => TRUE );

// Add 'mp4' files from a given directory to the 'videos' directory in the
zip file
$zip->addGlob( 'some-dir-path/*.mp4', 0, $options );

// Set options array to add the directory 'images' to the zip file
$options = array( 'add_path' => 'images/', 'remove_all_path' => TRUE );

// Add both 'jpg' and 'png' files from a given directory to the 'images'
   directory in the zip file
$zip->addGlob( 'some-other-dir-path/*.{jpg, png}', GLOB_BRACE, $options );

// You can also use regular expressions to get any files from a given directory
$zip->addPattern( '/\.(?:jpg|png)$/', 'another-dir-path', $options );

// Call the close() method to finish and save your new zip
$zip->close();

?>

Extracting files from an archive

To automatically unzip a compressed archive file, you can use the extractTo() method, which accepts two parameters:

destination

Where the files in the ZIP are being unzipped and saved to.

entries

The files you want to extract from the ZIP. You can grab one file at a time, an array of files, or, if you want to extract all the files in the ZIP, you can exclude this parameter:

<?php

// How to extract files from a zip file on your server
$zip = new ZipArchive();
$zip->open( 'compressed-dir-path/messenlehner-kids.zip',
     ZipArchive::CREATE );

// Use the extractTo() method to extract files in a zip on the server
// Extracts one file
$zip->extractTo( 'uncompressed-dir-path/', 'images/aksel.png' );

// Extracts files in an array
$zip->extractTo( 'uncompressed-dir-path/',
     array( 'images/cam.png', 'images/nina.png' ) );

// Extracts all files in the zip
$zip->extractTo( 'uncompressed-dir-path/' );

$zip->close();

?>

Other compression and archive PHP libraries

By default WordPress depends on ZipArchive for any file compression/decompression. WordPress actually first checks to see whether ZipArchive is available; if not, it falls back to another popular PHP library called PclZip. There are also some other compression and archive PHP libraries that you can use if you like:

• PclZip

• Bzip2

• LZF

• Phar

• Rar

• Zlib

PHPUnit

If you haven’t heard about unit testing, you should look into it. It’s a great method for regression testing your code and for automatically locating bugs/errors within your code. Think of it as writing code to automate the testing of your code. With PHPUnit you can set up specific unit tests to be performed on particular functions within your code to verify that those functions are doing everything they are supposed to be doing. We can’t iterate enough how important unit testing can be when you have multiple hands in the cookie jar. Give your clients and yourself more peace of mind by running unit tests before deploying any code updates to a production environment.

phpDocumentor

Every good developer knows that they should always provide good comments and additional documentation so any other developers looking at their code can easily figure out what is going on. This practice is also good for you if you’re looking at old code that you maybe wrote years ago, amiright? At the very least you should always leave good comments in your code. phpDocumentor is a great tool for automatically generating documentation from your code comments.

Faker

Faker is a great PHP library for automatically generating dummy content that can be used to populate a database, populate fake WordPress users, display fake content on a website you are building before you have real content, generating an XML feed, populating custom API endpoints, unit testing, or whatever you want to use it for. You can use the following formatters to make fake data, or you can create your own formatters using functions already defined in the Base class:

• Base

• Lorem Ipsum Text

• Person

• Address

• Phone Number

• Company Real

• Text Date and Time

• Internet User Agent

• Payment

• Color

• File

• Image

• Uuid

• Barcode

• Miscellaneous Biased

• Html Lorem

Goutte, a PHP-based website scraper

Don’t have access to a website data source and need to migrate it to WordPress? Need product data from multiple websites with no data feeds? Page scraping can be a great solution to some of your problems, but it can also be very time-consuming to programmatically find the patterns you are looking for within a web page (hopefully there is some consistency) and then parse that web page HTML markup based on the patterns to extract the data you need. If you are scraping content from multiple web pages, this can be a very daunting task.

Goutte is an awesome tool for screen scraping just about any data from any provided HTML markup, and you also can use it to parse XML. Goutte makes it easy for you to parse or crawl the data returned from an HTTP request using predefined methods that will easily assist you in identifying and extracting any HTML elements. Here are some of the cool things you can easily do with Goutte:

• Extract links from content.

• Extract images from content.

• Extract titles out of heading tags.

• Extract content out of <div> tags by their ID or class name.

• Extract sibling, parent, or child elements of an ordered or unordered list.

• Extract any content from within any HTML tags.

• Extract specific nodes from XML.

• Automatically click links.

• Automatically submit web forms.

• Automatically log into website (if you have a correct username and password).

Whoops, for user-friendly PHP errors

Whoops is a PHP library available as a Composer package that allows you to handle errors and exceptions in your code more elegantly. You can completely customize your PHP errors to include more helpful information than just the default PHP error message, which can sometimes be difficult to decipher. This is a great tool for managing and displaying errors to aid you in your troubleshooting efforts.

Directions

You can use this service to calculate directions between various locations and return step-by-step directions of what route(s) to follow. When creating a directions request, you can pass in an origin or a location for your directions to start, and a destination or the end location. You can also specify the travel mode: driving (default), bicycling, transit, or walking.

Distance Matrix

The Google Distance Matrix API is a service that provides travel distance and time for a matrix of origins and destinations. The information returned is based on the recommended route between the start and endpoints, as calculated by the Google Maps API, and consists of rows containing duration and distance values for each pair.

Elevation

This API provides a way to query elevation data for provided locations.

Geocoding

This API allows you to query geolocation data like latitude and longitude from a provided address. You can also use reverse geocoding to provide the closest address for a given latitude and longitude.

Street View service

This API allows you to interact with Google Street View. This API is really cool because you can access all of the photos and locations available in Google Street View.

Google Maps WordPress plugins

The following worthwhile WordPress plugins already utilize the Google Maps service:

WP Google Maps

One of the most popular WordPress plugins using Google Maps that allows you to easily build maps on your WordPress posts using shortcodes.

Gutenberg Map Block for Google Maps

If you are using Gutenberg and want to offer your users an easy-to-use Gutenberg Block for managing Google Maps, this plugin is your answer.

gPano

Easy-to-use WordPress plugin for embedding Google Street View panorama images into a post or page.

WP Store Locator

Easy-to-use WordPress plugin for adding physical locations with custom markers and information to maps. Locations can be searched by name and metadata as well as by radius to a given location. This plugin also leverages Google Maps Directions service to provide directions to a location.

Available migration plugins

Duplicator WordPress Migration Plugin is a solid plugin for moving your WordPress installations.

WP Migrate DB Pro is one of our favorite migration plugins for moving data to and from WordPress for simple and complex migrations. With this plugin you can easily export and import any and all of your WordPress database tables from one site to another. This is also a great plugin for working with production, staging, development, and localhost environments, as you can activate and configure it on all of your environments and easily move data around via the UX. This plugin offers several add-on plugins and you could certainly extend it with your own. Some of the notable add-ons include the CLI Add-on and the Multisite Tools Add-on.

WP Engine site migration tool

Some hosting companies like WP Engine offer migration tools you can use to make moving to its hosting platform super-easy. The company tries to take the entire manual process of moving your website or web app out of the equation.

Understand your data destination

Getting the content into WordPress is half the battle! We’ve always been big fans of writing scripts to automate populating databases. Whether by programming a simple web-based form for manually inputting data into a database or pulling out millions of records from one database and importing them into another, it’s all about getting the data to where it’s supposed to be in the format it’s supposed to be in. To do this, it’s very important to have a firm understanding of how all of your data is organized and stored in your destination database schema. Understanding the WordPress database schema and the helper functions within core WordPress that interact with the database is essential when it comes to migrating content into WordPress. If the WordPress database is somewhat of a mystery to you or you don’t fully understand it, maybe you shouldn’t have skipped This Post!

Understand your data source

So we know that our data destination is WordPress, but our data source can be anything. It can be another WordPress site; it can be another PHP and MySQL platform like Drupal or Joomla; it can be a proprietary database schema on MS SQL Server, Oracle, or any type of database; it can be data structured in XML or JSON being retrieved via an API; it could be a series of CSV files or even static HTML files. The list goes on and on, your data source can really be anything or go wherever the data you want to get into WordPress is stored. Whatever or wherever it is, you need to understand it, how it’s structured, and how the data will map to WordPress. We’ve seen and worked on just about everything when it comes to moving data into WordPress, and next we provide a short list of some data sources with which we have extensive work experience.

Data from databases

Most of our experience with platform migrations from an external data source to WordPress is from other SQL databases. Depending on the database engine, the database schema, and the database size, you might run into significant challenges when migrating your data:

MySQL database schemas

MySQL is free, very popular, and commonly used with most open source PHP-based content management systems or web publishing systems like WordPress, Drupal, Joomla!, Magento, ExpressionEngine, SilverStripe, and MediaWiki, to name a few.

Microsoft SQL server database schemas

SQL Server is not free, but is still very popular and used a lot to power anything from simple websites to enterprise-level web applications. Most of the time, SQL Server databases have a .NET web frontend.

Oracle database schemas

If you are running an Oracle database, you better be big time! If you have huge amounts of data (as in millions of records), it can be completely justified. However, we have worked with multiple clients that were using Oracle and it was just overkill. A fresh new user interface with WordPress and a MySQL database was the elegant, viable, and scalable solution they were really looking for.

Other database engines

There are other database engines out there and we’ve worked with all of them. Some other database engines include postgreSQL, DB2, mongoDB, Microsoft Access, SQLite, and Sybase, to name a few.

Data from files

Sometimes you may not have direct access to a database. You might be running your entire web application from files on a server or maybe you are able to generate only exports of files from your application. Regardless of how you get your hands on the actual files that contain your data, you need to understand how the data is structured within those files. The following are some typical file formats that contain data:

Comma-separated values (CSV)

You could have any type of delimited files, but CSV is the most common.

Extensible markup language (XML)

Commonly used to interchange data across the web, XML has a few formats, including RSS, Atom, SOAP, and XHTML.

JavaScript Object Notation (JSON)

If contained in a file, it is usually in a .txt file. JSON is a very popular format for exchanging data that is largely replacing XML.

Hypertext markup language (HTML)

If you made it this far in the blog, we assume we don’t need to explain this one.

Data from an external API

APIs are a very popular method of pushing and pulling data from one web-based system to or from another. We mentioned a few popular web services and APIs earlier in this article.

Page scraping

If all else fails and you can’t access any of your data, you can always scrape your data or content from any live website. The complexity of scraping a website’s content is dependent on how well structured the HTML of the website is. What you are looking for when page scraping is consistency.

Whatever your data source is, the idea is always going to be the same: parse the data, loop through it, and put it where it needs to go. Wow, we made that sound super-simple, but in most cases it really is if you have a firm understanding of WordPress and your data source(s).