I'm comfortable with HTML and CSS for static sites, but I want to build a dynamic image gallery in PHP. I already know how to load images from a folder, but I'd like to assign tags such as "landscape" or "building" and let visitors filter or sort the displayed images by those tags. Is a database necessary, or is there a simpler approach for a small gallery?
4 Answers
Embedding tags in filenames or EXIF metadata can work, but both approaches have drawbacks. Names like `beach_sunset_landscape.jpg` are quick for a tiny collection, yet they become awkward to rename and parse when an image has many tags. EXIF keeps the metadata with the image and can be useful across different systems, but reading and writing it is more complicated. A sidecar file such as `sunset.jpg.json` is another filesystem-based option if you want metadata stored next to each image.
You can filter entirely in the browser once the tags are included in the generated HTML. For example, PHP could output a data-tag attribute on each image or gallery item, and JavaScript could show or hide items when someone selects a tag. The important part is still storing the association between each image and its tags somewhere—HTML attributes alone won’t know which tags belong to files loaded from a folder.
For a small, mostly read-only gallery, a JSON file is probably the simplest option. Store each filename along with an array of tags, such as {"sunset.jpg":["landscape","building"]}. PHP can read the JSON, filter the records by tag, and then generate the gallery markup. It’s easier to maintain than encoding everything into filenames.
That sounds like a good fit for what I’m building. I’ll probably start with a JSON file and move to something more robust only if the gallery grows.
SQLite is another good middle ground. It stores everything in a local file, so you don’t need to run a separate database server, but you still get proper queries and indexes. It makes sense if you expect the number of images or tags to grow, or if you’ll need to edit and search the metadata frequently.
Exactly. The frontend approach handles the filtering, but PHP, JSON, a database, or some other metadata file still has to provide the correct tags for each image.