Bug report #14800
Problem rendering joined field from csv
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: |  Matthias Kuhn | ||
| Category: | Unknown | ||
| Affected QGIS version: | 2.14.2 | Regression?: | No |
| Operating System: | Easy fix?: | No | |
| Pull Request or Patch supplied: | No | Resolution: | |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 22757 |
Description
QGIS 2.14 hangs when applying gradient symbology on a joined field. Doing the same symbology on an attribute field has no problem. This problem does not exist in 2.12. Please find attached sample project.
Associated revisions
Avoid refreshing canvas for every joined feature
Instead of setting the provider's subsetString to fetch joined
features, use a feature request with FilterExpression instead.
(Setting the subsetString results in a canvas refresh.)
Performance should be similar (if expression compilation is
enabled) and this also has the advantage of avoiding provider-
specific behaviour (eg case insensitive matching).
(fix #14800)
Avoid refreshing canvas for every joined feature
Instead of setting the provider's subsetString to fetch joined
features, use a feature request with FilterExpression instead.
(Setting the subsetString results in a canvas refresh.)
Performance should be similar (if expression compilation is
enabled) and this also has the advantage of avoiding provider-
specific behaviour (eg case insensitive matching).
(fix #14800)
(cherry-picked from 22acf3b1a3e7a6afe094ec6dec83776256d2655a)
History
#1
Updated by Nyall Dawson over 8 years ago
- Assignee set to Matthias Kuhn
Matthias - ( assigning you just to draw your attention to this). I've tracked it down and it looks like it was caused by 0f2dfdb19bd1ace179a6b19cc1dbc4e4918d3f10 - "Reload data when subsetString changes.". The issue is that QgsVectorLayerFeatureIterator::FetchJoinInfo::addJoinedAttributesDirect repeatedly calls setSubsetString, and for every feature this results in the dataChanged() signal being emitted. This signal gets caught by map canvas and forces a redraw. So for every feature a redraw is occurring... ouch! Any ideas on a fix for this?
#2
Updated by Nyall Dawson over 8 years ago
- Status changed from Open to Closed
Fixed in changeset 22acf3b1a3e7a6afe094ec6dec83776256d2655a.
#3
Updated by Jürgen Fischer over 7 years ago
- Category set to Unknown