{"id":13301,"date":"2026-10-06T10:03:05","date_gmt":"2026-10-06T10:03:05","guid":{"rendered":"https:\/\/www.fhug.org.uk\/kb\/?post_type=kb_article&p=13301"},"modified":"2026-10-06T10:03:05","modified_gmt":"2026-10-06T10:03:05","slug":"writing-plugins-compatible-with-versions-7-8","status":"publish","type":"kb_article","link":"https:\/\/www.fhug.org.uk\/kb\/kb-article\/writing-plugins-compatible-with-versions-7-8\/","title":{"rendered":"Writing and Maintaining Plugins Compatible with Versions 7 and 8"},"content":{"rendered":"
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This article is a work in progress.<\/strong> It brings together what plugin authors have found so far while updating their plugins for \u0192h<\/span><\/span>8, and it will grow as more turns up. If you’ve come across something that isn’t covered here, or something here turns out to be wrong, please say so in Are there any adjustments to make to FH7 Plugins for FH8?<\/a> on the FHUG Forums.<\/p>\n<\/blockquote>\n

Introduction<\/h2>\n

Most plugins written for \u0192h<\/span><\/span>7 run in \u0192h<\/span><\/span>8 without any changes. Version 8 does change a few things underneath, though, and plugins that touch those areas may need work. This article lists the areas to check and the new facilities that are available to you. It assumes you’re already familiar with writing plugins for \u0192h<\/span><\/span>7; for earlier versions see Writing and Maintaining Plugins Compatible with Versions 5, 6 & 7<\/a>.<\/p>\n

The Plugin Help’s own summary of the changes is What’s New in Version 8?<\/a>. It also has a new section, Item Pointers: Confusions and Pitfalls to Avoid<\/em>, which Calico Pie recommend to all plugin authors.<\/p>\n

Testing Alongside Version 7<\/h2>\n\u0192h<\/span><\/span>8 installs alongside \u0192h<\/span><\/span>7 rather than replacing it, so you can test a plugin in both on the same PC. Each version keeps its own settings and its own copy of your plugins. When \u0192h<\/span><\/span>8 is first installed it copies your plugins across from \u0192h<\/span><\/span>7, but after that the two are independent: updating a plugin in one version doesn’t update it in the other. If you’re testing a new version of a plugin in both, load it into each.<\/p>\n

Folders, Files and the Registry<\/h2>\n\u0192h<\/span><\/span>8 uses different application and program data folders from \u0192h<\/span><\/span>7 (paths ending in Family Historian 8<\/code> instead of Family Historian<\/code>). A plugin with a hard-coded path into a \u0192h<\/span><\/span>7 folder will either fail or, worse, quietly read \u0192h<\/span><\/span>7’s files. Use fhGetContextInfo<\/code> and fhGetPluginDataFileName<\/code> to reference the locations applicable to your environment.<\/p>\n\u0192h<\/span><\/span>8 introduces one additional program data folder: Smart Folders<\/code>.<\/p>\n

Registry keys are now under Family Historian 8<\/em> rather than Family Historian<\/em>. A plugin that reads \u0192h<\/span><\/span>‘s settings from the Registry needs to look in the right place for the version it’s running in.<\/p>\n

64-bit<\/h2>\n\u0192h<\/span><\/span>8 is a 64-bit program, and all the Lua libraries that come with it are 64-bit. If your plugin uses a compiled library that you supply yourself (a DLL), you’ll need a 64-bit version of it; the 32-bit one won’t load.<\/p>\n

Plugins written purely in Lua are unaffected by the change itself, but timing can be. At least one well-known plugin that uses luacom to work with Windows ran into timing problems during the beta, so test anything that drives Windows or another program through luacom with particular care. Using luacom to create a FileSystemObject<\/code> directly, rather than through fhFileUtils, works as before (although fhFileUtils works too).<\/p>\n

Libraries<\/h2>\n\u0192h<\/span><\/span>8 comes with the LPEG pattern-matching library and its re<\/code> module, which \u0192h<\/span><\/span>7 didn’t. They make it practical to use regular-expression-style patterns where Lua patterns fall short. If a plugin uses them and must also run in \u0192h<\/span><\/span>7, it will need a fallback there.<\/p>\n

Most of the other bundled libraries are the same versions as in \u0192h<\/span><\/span>7. The exception is LuaFileSystem (lfs), which reports version 1.6.3 in \u0192h<\/span><\/span>8 against 1.7 in \u0192h<\/span><\/span>7. If your plugin relies on anything added in 1.7, test it carefully; lfs._VERSION<\/code> tells you which version you have.<\/p>\n

Addresses<\/h2>\n

Version 8 adds a new record type, Address (_ADDR<\/code>). Every address in an event or attribute now corresponds to an Address record, which in turn belongs to a Place record and can hold a map location, pictures and notes.<\/p>\n

If your plugin reads and writes addresses with fhGetValueAsText<\/code> and fhSetValueAsText<\/code>, little changes: address fields can still be treated as text. You need to take more care if you:<\/p>\n

When a plugin has been tested, mark it as compatible with Version 8 in the Plugin Store. Users are advised to check that before relying on a plugin (see Using Plugins in Version 8<\/a>).<\/p>\n