Creating and editing e-books with Sigil

Validator Code

One of Sigil's strength is in validating an e-book. The multi-step validation process ensures that a document meets current EPUB standards. Sigil takes both (X)HTML and CSS code into account, as well as the e-book structure and its metadata.

Sigil examines HTML code with Tidy [9] for syntactical errors. This tool is already integrated to quickly identify and resolve errors. Once an error is found, the program reports it in a dialog and identifies its approximate location in the source code (Figure 5).

Figure 5: Sigil fixes simple syntactical flaws mostly automatically. It also recommends solutions for manual fixes.

Even metadata can be incomplete or have errors. Sigil uses the FlightCrew [10] integrated metadata validator to find unused files and the like.

In its reports, Sigil summarizes information from different sources. Through these reports, the program provides details on integrated HTML/CSS files, images, and much more (Figure 6).

Figure 6: Sigil uses reports to provide statistics for the files used.

Conclusion

Sigil presents itself as an easy-to-use EPUB document editor. Numerous keyboard shortcuts for often-used functions are available, and the different editing modes, from source code to complete WYSIWYG mode, prove useful for text input, editing, and more complicated tasks or troubleshooting.

Additionally, the various built-in validation tools for spelling, syntax, and metadata provide valuable assistance. Many special functions add hyperlinks, among other things, and can help in creating e-books. A useful enhancement for beginners would be a wizard to guide users through the various steps (see the "Building EPUBs" box).

Overall, the Sigil editor leaves a good impression – too bad it's designed only for e-books.