Viewer history enable/disable control is broken

Supposedly it is possible to disable pdfjs viewer restoring viewer state by setting disableHistory to false (is this key even documented anywhere?), but it’s not working at all.

Adding #disableHistory to URL in the viewer does disable the history, but that’s caused by a bugged handling: adding any non-empty hash to the URL will cause history to be disabled.

Meanwhile, trying to set disableHistory through defaultOptions or AppOptions does nothing. The only place where it’s used is inside _initializePdfHistory, but it isn’t doing anything there either since pdf.history will be created regardless.

[Snuffleupagus]

Supposedly it is possible to disable pdfjs viewer restoring viewer state by setting disableHistory to false

That option only controls the browsing history implementation, i.e. https://github.com/mozilla/pdf.js/blob/master/web/pdf_history.js, which allows you to use the back button in the browser to navigate to a previous position after e.g. clicking on a LinkAnnotation within a PDF document.

[…] but it’s not working at all.

Yes, it most certainly does exactly what it’s supposed to!

https://github.com/mozilla/pdf.js/blob/d02233361872d3758eb23ed394c939c4f510e2cb/web/app.js#L1226-L1242

Based on the quoted code your question isn’t actually about PDFHistory but rather about ViewHistory (which is a separate thing, that only stores the last position in localStorage and nothing else). That implementation is controlled by the viewOnLoad option/preference, with the following currently supported values: https://github.com/mozilla/pdf.js/blob/d02233361872d3758eb23ed394c939c4f510e2cb/web/app.js#L89-L93

Hence setting viewOnLoad = 1 is sufficient to discard any view and/or browser history entries and always load all documents at the first page (and with default zoom values).

---

For future reference: When opening an issue, please remember to provide all of the information requested in https://github.com/mozilla/pdf.js/blob/master/.github/ISSUE_TEMPLATE.md

Furthermore, this issue required some amount of “reading between the lines” to figure out what you really were asking about; hence please see https://github.com/mozilla/pdf.js/blob/master/.github/CONTRIBUTING.md (emphasis mine):

If you are developing a custom solution, first check the examples at https://github.com/mozilla/pdf.js#learning and search existing issues. If this does not help, please prepare a short well-documented example that demonstrates the problem and make it accessible online on your website, JS Bin, GitHub, etc. before opening a new issue or contacting us in the Matrix room – keep in mind that just code snippets won’t help us troubleshoot the problem.

[Voileexperiments]

I downvoted because while it answers the question, it also dodges the underlying issue of the lack of documentation about viewer configs (what config should I change to achieve anything different from default behaviour?). I am customizing the existing viewer and I find myself often needed to dive into the initialization logic itself just to understand where should I change the code (and then guess wrong, just as this issue has proven). I don’t think this is encouraging to customizing the default viewer.