Defect #6348


Gantt chart PDF rendering errors

Added by Eric Davis almost 14 years ago. Updated over 13 years ago.

Target version:
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When rendering the new Gantt chart (#6276) with a large chart, the PDF export gets off and creates multiple almost-empty pages.

Unfortunately, it looks like the older Gantt chart wasn't exporting PDFs correctly either so this section might need to be rethought.

Related issues

Related to Redmine - Feature #6276: Gantt Chart rewriteClosedEric Davis2010-09-03

Actions #1

Updated by Mischa The Evil almost 14 years ago

  • Category changed from Issues to Gantt
Actions #2

Updated by Eric Davis over 13 years ago

  • Assignee deleted (Eric Davis)

I am stepping down from working on Redmine. If someone else is interesting in working on this issue, feel free to reassign it to them.

Eric Davis

Actions #3

Updated by Jean-Philippe Lang over 13 years ago

  • Status changed from 7 to New

The way the new gantt chart generates PDF (all subjects then all lines) makes it hard, if not impossible, to fix without some refactoring.

Actions #4

Updated by Greg Mefford over 13 years ago

From studying the existing code for rendering Gantt PDFs, it looks like it's a pagination issue where a possible solution would be to pre-compute what you want to render, paginate, then render each page. This is instead of just rendering as you go, which it seems is causing the overflow as soon as it's too much for a single page.

I'm going to look into it further, but don't let that stop someone else from fixing it; I can't guarantee I'll find the time to actually fix the bug.

Actions #5

Updated by Greg Mefford over 13 years ago

I've started working on a patch that seems to be doing the trick. It's not quite done, but perhaps I can finish it tomorrow.
This gantt code really feels like it could use some refactoring, but I'm having some success hacking in the pagination.

Actions #6

Updated by Greg Mefford over 13 years ago

  • Status changed from New to Resolved

That Gantt code could use some more attention, but in the mean time, here is some code that generates proper PDFs with a large number of rows (like more than 50).

I've sent a pull request to edavis10 on Github, but in case he doesn't have time and someone else wants to integrate, here is a link:

Actions #7

Updated by Jean-Philippe Lang over 13 years ago

  • Status changed from Resolved to Closed
  • Resolution set to Fixed

I fixed the problem in a similar way as your patch does, in r4474, thanks. This change takes part in some refactoring that I'm doing in order to get more reasonable response times for an average cross-project chart with a few hundreds issues.


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