I have seen this part but it is not exactly what I want. I want to choose a directory and force Jalbum to process it.
Not sure of that but when I change Exif user comment in a pic the date does not change and jalbum not process it.
There is no way to tell jAlbum "process this subdirectory and no others."
But changing the EXIF User Comment on the image file in the project directory should trigger processing, as long as the utility you are using to change the EXIF is updating the "date modified" on the file. I just did a quick test, and it worked as expected. But remember, jAlbum is looking at the copy of the image file that's sitting in the project directory - it's not looking at the original that's somewhere else on your system.
If you want jAlbum to keep track of the original files somewhere else, add them as links instead of having copies made.
Great tip but can one do that individually from within the jAblum interface? For example, I create a text file and transfer the text into an image for a "nice" looking page like this. I keep the .txt file in the same folder as the image created therefrom, and, include original .xcf (GIMP) file - for later corrections if needed. I have adopted this approach over PDFs, which are "uglier" and About pages that are not easily seen.
This is done of the fly. In other cases, at initial setup, I have both RAX and .jpg images in the folder. Eventually, when satisfied w/ .jpg images, I clean house. The more I talk about this, the less advantage I see to links. I could keep the newly created resources in a separate folder and mark is for omission / non-processing.
Sorry for the long-winded answer - you got my head to spinning!
On your specific need to include text pages, I'd recommend you to add "Pages" in jAlbum instead of adding text to images. This also has an SEO advantage
I have experimented with About, etc. But they get positioned not where I want them. I'd like a page of text, written in html, to appear in the "middle" of an album or folder as in this example, NFTest - look at the Orientation folder. The fourth image is an example of what I've done. (Being an image of a text page, it does render quite correctly - ragged edges of text.) I tried adding a "New Page" at the top - not what I want, position-wise. Please ignore typos - I've not done a spell check.