Book Browser

The Book Browser (BB) offers a view into the structure of your EPUB book. You can see all the different files that make up the archive, from XHTML files to images.

Hint

If your not familiar with the internal structure of an EPUB file, see the EPUB Overview chapter.

The Book Browser pane can be either docked, or undocked. A docked BB can be undocked by clicking on the little window icon in the top right corner, and docked by simply dragging the new window to the edge of the main Sigil window and then releasing the mouse button. An image of it undocked can be see in Book Browser, undocked.

You can also open and close the Book Browser through the View menu.

Book Browser, undocked

Content folders

The view is organized into several folders which can be expanded or collapsed by clicking on the little arrow icon next to them:

• Text — all the XHTML files that make up the text of the work;
• Styles — the CSS and XPGT stylesheets;
• Images — PNG, JPG, GIF and other image types you have in your book;
• Fonts — TTF and OTF fonts;
• Misc — miscellaneous files.

In most folders, the files are listed alphabetically. The exception is the Text folder in which the files are listed in their reading order. Since the EPUB archive consists of several XHTML files (customarily one per book chapter), the order in which they are displayed to the user needs to be determined in advance. Thus, the Text folder allows you to click a file and drag it amongst the other files in that folder. The file at the “top” is the one which will be shown to the user first, and the one at the bottom will be shown last.

Context menu

Right-clicking on an item in the Book Browser brings up a context menu, and depending on the item on which you invoked the menu, you’ll be able to:

• Add existing items,
• Add new items,
• Remove the file,
• Rename the file,
• Add semantic information.

If you select Add existing items, then an Open file dialog will be shown. From here, you’ll be able to add any type of file that can be embedded inside an EPUB, and they’ll be automatically routed to the correct folder. If you pick an HTM, HTML or XHTML file (or several), Sigil will also import all the resources that those files reference, like CSS stylesheets or images (but not other XHTML files). Using this technique, you can build up your EPUB file from several HTML files prepared in advance.

The Add Semantics sub-menu is special. It is only displayed for XHTML files and images, and the contents differ. When invoked on an XHTML file, it enables you to indicate that that file contains the book’s dedication section, the glossary, the foreword, the preface and many more [1]. Some (but few) Reading Systems will then use this information and display it to the user.

For images, a different semantic action is offered. You can mark an image as a cover. This bit of semantic information is important for several Reading Systems, the most prominent of which is the iBooks application for the iPad. If an image is not marked as a cover, the book won’t have a cover set in the iBooks “bookshelf”.

Hint

Sigil has heuristics that will mark the appropriate image as the cover if you don’t do it yourself. If the first file in the reading order is “very small” and has only one image in it [2], that image will be selected as the cover.

So if you follow best practices, Sigil helps you out. Still, mark it by hand if you can. You will always know better than the machine.

[1]	For those interested in the technical details, this information is stored in The OPF file‘s <guide> element.

[2]	Sigil looks for a normal <img> tag or an SVG <image> one.