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Wed Feb 19 04:00:31 2020

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QGIS Planet

FOSSGIS Konferenz 2012 in Dessau

Die FOSSGIS und deutschsprachige Open Street Map Konferenz 2012 – die grösste deutschsprachige Anwenderkonferenz für Freie Geo-Informationssysteme und freie Geodaten – findet vom 20. bis 22. März 2012 an der Hochschule Anhalt in Dessau-Rosslau statt.

Sourcepole ist mit folgenden Vorträgen und Workshops vertreten:

Da mehr als 400 Teilnehmende erwartet werden, ist eine Registrierung bis zum 16. März 2012 notwendig. Das Anmeldeformular und andere organisatorische Informationen befinden sich auf der Konferenzseite.

FOSSGIS Konferenz 2012 in Dessau

Die FOSSGIS und deutschsprachige Open Street Map Konferenz 2012 – die grösste deutschsprachige Anwenderkonferenz für Freie Geo-Informationssysteme und freie Geodaten – findet vom 20. bis 22. März 2012 an der Hochschule Anhalt in Dessau-Rosslau statt.

Sourcepole ist mit folgenden Vorträgen und Workshops vertreten:

Da mehr als 400 Teilnehmende erwartet werden, ist eine Registrierung bis zum 16. März 2012 notwendig. Das Anmeldeformular und andere organisatorische Informationen befinden sich auf der Konferenzseite.

A new QGIS plugin: Python Script Runner

Gary Sherman has just published a new Python plugin for QGIS that I think people will find very handy, I know I will.  The plugin allows you to run Python scripts inside QGIS for tasks that don’t really require, or warrant, a whole plugin.

Go check out Gray’s post about the new plugin at http://spatialgalaxy.net/2012/01/29/script-runner-a-plugin-to-run-python-scripts-in-qgis/

The new plugin can be installed via the Plugin Installer using the “runner” or “script”.  The Plugin Installer is another one of my favorite plugins for QGIS, being able to push out a new plugin and know that everyone can get it is a good feeling :)


Filed under: Open Source, qgis Tagged: FOSSGIS, gis, Open Source, osgeo, plugin, python, qgis, Quantum GIS

Improvements to the QGIS rule based rendering

The rule based rendering in QGIS has just got a make over to improve in some of the old usability issues it used to have.  Most of the improvements are UI related. If you would like to try them out you will need to grab a copy of the latest dev build (qgis-dev in OSGeo4W)

Main improvements include:

  • Nested rules.  If the parent rule evaluates to false none of the child rules are applied. This replaces the priority system in the old dialog.
  • Disable symbol for rules. Rules with no symbol only act as a check for the child rules e.g nothing is rendered for the rule but child rules still are (unless also disabled).
  • Drag and Drop rules (multi-selection is supported).  Rules can be dragged onto other rules in order to nest them and set up a rendering hierarchy.
  • Inline editing of rule labels, expressions, scales
  • Overall tweaks to the dialog

The new rule dialog

As you can see in the screenshot, the rules are now organized in a tree which clearly expresses which rules should be applied and when.

In the example above, all the rules under the Sealed rule will only be applied if that rule is true. The old system would have you managing all rules in one big list and dealing with priorities in order to get the rules to apply right, the new dialog is a major improvement.

And the results! As you can see below, QGIS will only render the colored squares if the Sealed rule is true otherwise it just shows a green line.

The rules applied

The work was sponsored by Ville de Morges, Switzerland and developed by Martin Dobias.  Thanks to both of them for these improvements.

More info:

Note: As this is a brand new feature there might be some bugs, or things that don’t quite work as expected. If you do find something don’t hesitate to file a bug report at hub.qgis.org so it can be fixed, or at least known about.


Filed under: Open Source, qgis Tagged: FOSSGIS, gis, map-rendering, mapping, Open Source, osgeo, qgis, Quantum GIS, styling

QGIS support for MS SQL Server 2008 – Coming Soon!

Good news!

Support for MS SQL Server 2008 in QGIS is coming soon.   A native QGIS provider for MS SQL Server is currently being worked on to make using, managing, and editing SQL Server data in QGIS just as easy as PostGIS.

The work is being sponsored by the Australian company Digital Mapping Solutions. So a very big thanks to them for this great feature!

There is no ETA on when it will be added to the main QGIS build, but the provider is currently in testing stage and hopefully will be in there soon.

So if you have been itching to try SQL Server data in QGIS, hang in there as a good solution is just around the corner.

P.S The other blog posts on this topic I used ogr, this method will still work fine after the native provider is added, however the native driver will add a nicer interface including integration into the QBrowser, better optimization for the QGIS code, and hopefully same feel as the PostGIS experience.


Filed under: Open Source, qgis Tagged: digital mapping solutions, FOSSGIS, gis, ms sql server, MS SQL Server 2008, MS SQL Spatial, ogr, Open Source, qgis, Quantum GIS

Expression based labeling now in QGIS.

QGIS finally has expression based labels! (Although you must be running latest dev build)

What does that mean? Well QGIS used to be only able to label with a field from the layer, very limiting if you need to make a nice looking label string. Now you can use expressions (eg ‘Up ‘ || US_Invert || ‘some more text’ ) to label the feature, just like this.

Example of expression based labels

This is something that I missed a lot when moving from MapInfo to QGIS.  After opening a ticket on the QGIS bug list and nothing happening with it for a couple of months (not that I expected anything to, everyone is busy enough as is.  I don’t expect the devs to just jump at all my requests) so I decided I should at least attempt adding it myself.  The joys of open source!

Turns out adding the expression labeling was the easy part, however there was no good generic expression string builder that I could use to build the expression string.  QGIS already had the expression builder for the query window and the field calculator, however the code was very tied down to only work for those implementations, plus they didn’t scale with the increasing function list.  I’m not going to go and make yet another dialog just for the labeling.  Uniformity is the key to good user experience.

After searching around to see what other GIS systems did to get some inspiration it seemed that every example that I came across was, in my opinion, poor.    Although there was one ArcGIS idea ticket that gave me a few ideas http://ideas.arcgis.com/ideaView?id=087300000008IbHAAU

So with that I started working on a generic expression builder that could be used to build an expression string anywhere, replacing the query window and field calculator in due time. One ring widget to rule them all, one ring widget to bind the, etc.

The result

Generic expression builder

Key features of the new expression builder:

  • Live validation of expression
  • Real time searching
  • Live output preview
  • Help on selected item.
  • Easier to add new functions without changing the UI.  Function list is read right from the expression parser.  No more hidden functions.
  • Reusable widget

If the expression hits an error while you type you will be shown an “Expression is invalid” warning (yes I know it’s wrong in the screen shot). Clicking (more info) or hovering over the expression area will show you the error.

Expression has error

Searching can done by using the search box at the top. The function list will reduce to show only functions or fields containing that string (Note: it is case sensitive at the current time) .

Searching for a function or field name.

Still to do

As with all programming it is never bug free so I expect, now that it is open to wider testing, that there might be a few that need to be addressed .   There is also very limited function help written for the functions, although if anyone is willing to have a go at it I’m more than happy.

If you do find any bugs will the widget/dialog you can open a ticket at http://hub.qgis.org/projects/quantum-gis/issues , assign it to me and I’ll see what I can do.

In the works

  • Simple Syntax highlighting
  • Recent expression used list
  • Saved expressions
  • Auto bracketing (maybe)
  • UI tweaking

I would like to thank Martin from the QGIS team for reviewing my code all though the project and helping me improve the code and idea.  Also thanks to all the other people who gave ideas for the widget/dialog.

Enjoy!


Filed under: Open Source, qgis Tagged: FOSSGIS, gis, Open Source, osgeo, qgis, Quantum GIS

Generating contours using GDAL ( via shell or QGIS)

I tell you. It always amazes me how much cool stuff you can do with great open source GIS software these days. GDAL is one of those great open source projects that I have just found a great use for (apart from just opening every raster type under the sun in QGIS).

GDAL has the ability to generate contours from a DEM, something that I have always wanted to try for my town but have never been able due to lack of a good DEMs.

Recently we purchased a set of DEMs that cover a large area as part of a study. Each DEM uses a grid size of 1mx1m. Prefect for generating contours.

Using the GdalTools QGIS plugin.

First make sure that you have the latest version of the GdalTools plugin installed (GdalTools should be installed by default with QGIS. If it’s not, search “Gdal” in the plugin installer). Enable the plugin once it’s installed.

Load the DEM into QGIS using the Load Raster icon.

DEM loaded in QGIS

Now head up to the menu Raster->Extraction->Contour

Raster menu in QGIS

Select the settings that you need. For this DEM I am going to generate 250mm contours.

Contour dialog.

Take note of the text area at the bottom of the dialog as that is the exact command sent to GDAL in order to generate the contours. If you take a copy of that you can run it on the command line for batch processing later.

Hit ok.

250mm contours from the DEM

BAM! :)

Using the command line/shell.

Using QGIS for a one off DEM is fine and dandy but what if you have 3000 DEMs that you need to process. To hell with doing that by hand!

Remember the contour tool in QGIS told us the exact command line args to use, so creating a shell script for automating the process is pretty easy.

for f in *.asc
do
  echo "Processing $f"
 gdal_contour -a ELEV -i 0.25 $f $f-250mm.shp
done

The above code will loop though the current directory and process all the DEMs generating 250mm contours for each one. It saves each new contour file as {filename}-250mm.shp. You will need to change *.asc to whatever format your DEM is in.

Copy the above code into a file somewhere and call it generate_contours.sh. This can then be called from the command line using

sh generate_contours.sh

Running sh on Windows

If you’re a windows user you will need to run OsGeo4W Shell in order to use sh.

Loading OsGeo4w shell.

Once the shell is loaded you can just call:

sh generate_contours.sh

Output from running generate_contours.sh

Final remarks

I ran the above sh script on a folder with about 2500 DEMs and it took around 4 hours to complete the whole folder. Of course performance will vary but it seems pretty quick considering.

Once again the possibly to use open source GIS tools to get my work done is amazing.  No expensive software here.

So far I’m not aware of any line smoothing/generalizing abilities using GDAL/OGR.  Although you can import the contours into GRASS and use that: http://grass.osgeo.org/wiki/V.generalize_tutorial

You can also generate the contours using GDAL via Python but that is a topic for another day.


Filed under: Open Source, qgis Tagged: contours, DEM, FOSSGIS, gdal, gis, grid, ogr, Open Source, osgeo, qgis, Quantum GIS, raster

Visualizing QGIS code activity between 1.6 and 1.7 – Video

Here is a quick video I did this morning using the very cool tool Gource. The video shows all the commits (1265) that were made between release 1.6 and 1.7. QGIS 1.7 was released on 19th June 2011 but there was still some clean up in the 1.7 branch paste that date into September.

It’s interesting to note the large burst of activity around November.


Filed under: Open Source, qgis Tagged: FOSSGIS, gis, git, Gource, Open Source, qgis, Quantum GIS

QGIS Tips – Custom feature forms with Python logic

Last week I found a nice little undocumented feature of QGIS. I plan on writing documentation, so it won’t stay that way for long but I thought I would post about it first and run though it step by step.

This post is going to be a follow up post based on what Tim Sutton did for the same subject back in 2009 at http://linfiniti.com/2009/11/creating-dynamic-forms-a-new-feature-headed-for-qgis-1-4/

For data entry one feature I really like in QGIS is the automatic feature edit forms with support for textboxs, dropdowns and all sorts of other cool Qt controls to make data entry a breeze.

However one thing that people might not be aware of is that you can have a custom forms for data entry. QGIS will take care of setting all the fields and then saving the values back to your layer.

This could be handy if you want to have say a logo, some validation and maybe some text to help the user fill in the form correctly. Or just a custom form layout because you can.

One thing Tim didn’t follow up on was a post about how to add custom Python logic to the form, which I think is the coolest feature of having these custom forms.

So lets get started.

Creating the custom form

This process is pretty much the same as what Tim outlined in his blog post however I’m going to go over it again for completeness.

In order to create the custom form you will need to install Qt Desinger. For windows I haven’t found a way to just install the desinger although if you have QGIS installed it is normally installed with the Qt framework and can be found at C:\OSGeo4w\bin\designer.exe. If you’re on Linux you can run something like

sudo apt-get install qt4-designer

Ohh how I wish windows had a package management system :(

Fire up Qt Desinger and select “Dialog with Buttons Bottom”.

Lets throw on a couple of Labels and a few Line Edits for the data. Now set the form to use a Grid Layout (Right Click on empty space on form->Layout->Layout in Grid).

Now the trick in making a custom form for QGIS is naming the object the same as the field. So I my case I have a road layer with the following fields.

- Segment_ID
- Parcel_ID
- Name
- Alias_Name
- Locality
- Parcel_type

For my custom form I only care about Segment_ID and Name, so my form looks like:

Custom form in Qt Designer

Note that I have set the read only property of the Segment ID line edit to True so that it can’t be edited. I don’t want people messing around with the ID.

As I said above the tick is in the naming so right click on each line edit and select Change objectName, naming each line edit using the same name as the field. For me the first control is called Segment_ID and the other is called Name.

Make sure the objects are the same name as the field.

Save the form into a new folder, I have put mine in C:\Temp\Roads. Jump back into QGIS, load the properties dialog for the layer. Select the General tab and set Edit UI to the new form .ui file.

Setting the edit form UI file.

Save and exit the properties window. Enable the layer for editing (or not) and select an object with the Identify Feature tool.

Woot! Custom edit form in QGIS.

Magic! As I’m in edit mode any changes I make to the Name line edit will be reflected back on the layer (but not the Segment ID as it’s read only). If you are in non-edit mode then you are given the custom form with everything disabled and a cancel button.

With Python validation and custom logic.

Now creating a custom form like above is pretty cool although having some custom Python validation behind it would be even cooler.

What I want to do is add some validation to the Name field so the user can’t enter null road names.

First save your QGIS project (as the Python code runner will look where the project is saved for the Python module). Again I have saved mine in C:\Temp\Roads as Roads.qgs. Now lets make a new python file in your favourite text editor and add the following code.

from PyQt4.QtCore import *
from PyQt4.QtGui import *

nameField = None
myDialog = None

def formOpen(dialog,layerid,featureid):
	global myDialog
	myDialog = dialog
	global nameField
	nameField = dialog.findChild(QLineEdit,"Name")
	buttonBox = dialog.findChild(QDialogButtonBox,"buttonBox")

	# Disconnect the signal that QGIS has wired up for the dialog to the button box.
	buttonBox.accepted.disconnect(myDialog.accept)

	# Wire up our own signals.
	buttonBox.accepted.connect(validate)
	buttonBox.rejected.connect(myDialog.reject)

def validate():
  # Make sure that the name field isn't empty.
	if not nameField.text().length() > 0:
		msgBox = QMessageBox()
		msgBox.setText("Name field can not be null.")
		msgBox.exec_()
	else:
		# Return the form as accpeted to QGIS.
		myDialog.accept()

Wow! What the hell is all that! I’ll step though the code to explain each bit.

Code break down.

First import the modules from Qt and set up a few global variables to hold the dialog and name field.

from PyQt4.QtCore import *
from PyQt4.QtGui import *

nameField = None
myDialog = None

Now we create a method that QGIS will call when it loads the form. This method takes an instance of our custom dialog, the Layer ID, and the Feature ID.

def formOpen(dialog,layerid,featureid):

Then using the findChild method we want to grab the reference to the Name field and the button box. We are also calling buttonBox.accepted.disconnect() to disconnect the slots that QGIS has auto wired up to our button box, we do this so we can hook up our own accepted logic.

After we have disconnected the accepted signal we can wire up our own call to the validate method using buttonBox.accepted.connect(validate).

global myDialog
myDialog = dialog
global nameField
nameField = dialog.findChild(QLineEdit,"Name")
buttonBox = dialog.findChild(QDialogButtonBox,"buttonBox")

# Disconnect the signal that QGIS has wired up for the dialog to the button box.
buttonBox.accepted.disconnect(myDialog.accept)
# Wire up our own signals.
buttonBox.accepted.connect(validate)
buttonBox.rejected.connect(myDialog.reject)

We need a method to validate the logic. This will be called when the signal buttonBox.accepted() is called. The logic in this method should be pretty streight forward. If the Name line edit has a length > 0 then we accept the dialog, if not then we give the user a message and let them fix the mistake.

def validate():
  # Make sure that the name field isn't empty.
	if not nameField.text().length() > 0:
		msgBox = QMessageBox()
		msgBox.setText("Name field can not be null.")
		msgBox.exec_()
	else:
		# Return the form as accpeted to QGIS.
		myDialog.accept()

Almost done!

Now that you have a Python file with the custom validation logic we need to tell QGIS to use this logic for the form. First save the Python file in the same directory as your project. I have called mine C:\Temp\Roads\RoadForm.py.

Back on the General tab in the layer properties we can set the Init function field. We set this to call the module and function we just made. The syntax is {module name}.{function name}. In my case my module (the Python file we made before) is called RoadForm and the function is called formOpen, so it will be RoadForm.formOpen.

Set the Init function field to moduleName.functionName

Save and use the Identify Feature tool to select a feature. You shouldn’t get any errors if everything worked ok. Now delete everything in the Name field and hit Ok.

Validation in action

Sweet! The form can now not be accepted if the name field is null.

And that’s that. Pretty simple but powerful feature once you know how to set it up.

Enjoy!

If you do end up using this custom form with python logic stuff in the real world, leave a comment and maybe a picture. It would be good to see use cases for this cool QGIS feature.

Bonus

Why not add a red highlight to the textbox if something is not valid.

from PyQt4.QtCore import *
from PyQt4.QtGui import *

nameField = None
myDialog = None

def formOpen(dialog,layerid,featureid):
  global myDialog
  myDialog = dialog
  global nameField
  nameField = dialog.findChild(QLineEdit,"Name")
  buttonBox = dialog.findChild(QDialogButtonBox,"buttonBox")

  nameField.textChanged.connect(Name_onTextChanged)
  # Disconnect the signal that QGIS has wired up for the dialog to the button box.
  buttonBox.accepted.disconnect(myDialog.accept)
  # Wire up our own signals.
  buttonBox.accepted.connect(validate)
  buttonBox.rejected.connect(myDialog.reject)

def validate():
  # Make sure that the name field isn't empty.
  if not nameField.text().length() > 0:
    nameField.setStyleSheet("background-color: rgba(255, 107, 107, 150);")
    msgBox = QMessageBox()
    msgBox.setText("Name field can not be null.")
    msgBox.exec_()
  else:
  # Return the form as accpeted to QGIS.
    myDialog.accept()

def Name_onTextChanged(text):
  if not nameField.text().length() > 0:
    nameField.setStyleSheet("background-color: rgba(255, 107, 107, 150);")
  else:
    nameField.setStyleSheet("")

The key part of of this is nameField.textChanged.connect(Name_onTextChanged) and the Name_onTextChanged(text) method. Give it a try, I think it looks quite nice.

Change text background to red on invalid input.


Filed under: Open Source, qgis Tagged: FOSSGIS, gis, Open Source, qgis, qgis-editing, Quantum GIS

Slow opening of rasters in QGIS 1.7? Here is a fix.

Note: The following post only applies to QGIS 1.7.  QGIS 1.7.1 (upcoming patch) will not have this issue as the default behavior has changed. 

One thing I noticed when running QGIS 1.7 was my rasters were really slow to open and sometimes froze QGIS.  I thought maybe it was some bad plugin that I had installed, nope; maybe opening the raster of the network drive was causing it to be slow, nope. I tried a bunch of stuff, still nothing.  After a while a few other people posted to the mailing list saying they were having the same issue, turns out the solution was very simple.

In QGIS contrast enhancement for rasters is turned on by default, so each time a raster is opened QGIS had to calculate the stats (max and min for example) for the raster and then scale the contrast.  For a large raster this is pretty heavy and this was the cause of all those problems.

So what’s the solution?

Turns out QGIS will remember the contrast setting for all rasters if you want it to.

To fix the slow opening raster problem:

  1. Open a small raster (just any old picture will do)
  2. Double click the layer in the layer list
  3. Change Contrast Enhancement to No Stretch

    Change Contrast Enhancement to No Stretch

  4. Hit the little Save icon next to the drop down box
  5. Open your big raster.

That setting will now be remembered for each raster that is opened and improve the loading time.

On a similar note.  Tim over at http://linfiniti.com has done some work to improve the raster performance even more with http://linfiniti.com/2011/08/improvements-to-raster-performance-in-qgis-master/ .  The improvements that  Tim has made are available in the nightly build of QGIS via qgis-dev in OSGeo4W, or by building the master line from github.com.

 


Filed under: Open Source, qgis Tagged: FOSSGIS, gis, Open Source, OSS, QGIS 1.7, Quantum GIS, rasters

QGIS edit tools brainstorming or What edit tools should QGIS have?

One trend that come up a lot in the poll I recently ran (results will be out soon, just writing a summary blog post) is “Needs more powerful edit tools“.  And I agree.

Coming from a MapInfo background nothing much changes when you move to QGIS, MapInfo had the simple Add Point, Add Region, Add Line kind of tools and then you need to use plugins to do anything a bit more advanced (MapCAD).  QGIS has the start of a kind of MapCAD thing happening although not as complete.

Why not just let people write plugins?

However I think in order to make QGIS a more attractive package to a lot of people it needs to get some built in semi-advanced to advanced editing tools;  getting back to those poll results of “Needs more powerful edit tools”.

I thought to myself “What would I like QGIS to be able to do when it came to editing?” although I came up with a small set my editing needs are only relatively small.  I then thought the best way to find out what people need is to just create a blank canvas for people to throw their ideas around on and then go from there.

Why not just create a ticket?

My idea is to get a larger idea of what people need and want rather than just one-off tickets. Although the ideas will be at the edit tool idea level it will be easier to see how they should all fit together if they are all in one place and editable by other people.  You can then start asking questions like: Do we really need that UI there?  Can we merge these tools?  How should the output be handled?

The overall goal is to have a tight, thought out, group of edit tools rather then someone creating a plugin over here for one thing and some else creating something else over there.

So how do we get this going?

Well I have created a Google Document that anyone can edit and view in order to start brainstorming ideas. The link can be found here.

I have already created an example of two ideas that I would like to see.

So go ahead, throw some ideas up.  I’m interested to see where this can head.

Why use Google Docs and not the QGIS wiki?

Mainly because Google Docs makes it very easy to do frictionless editing of a document together.  No need for user names or passwords or overwriting someone else’s changes (Google Docs is all real time).


Filed under: Open Source, qgis Tagged: FOSSGIS, gis, mapping, Open Source, OSS, poll, qgis, qgis-editing, Quantum GIS

FOSSGIS2011 – After Action Report

FOSSGIS2011 in Heidelberg was a great success for the QGIS project and for me personally. The audience was really impressed by Marco’s and Andreas’ presentation on QGIS Mapserver and GeoExt Web Client. My presentation on Time Manager for QGIS was followed by a series of interesting questions and comments concerning use cases in e.g. land use mapping. Requested features include support for raster layers and support for timestamps before year 19xx.
I’ll be posting an English version of the Time Manager presentation including some additional comments here soon.


FOSSGIS 2011: Vergleich von Open Source Virtual Globes

Mittlerweile gibt es mehrere Open Source Alternativen zu Google Earth, wie z.B. Nasa World Wind Java SDK, ossimPlanet oder osgEarth. Dieser Vortrag soll eine Übersicht aktueller Open Source Virtual Globes bieten und einige Vorschläge zu erwünschten Funktionen liefern.

Präsentation

Demos:

NASA World Wind Java SDK

ossimPlanet

gvSIG 3D

osgEarth

osgEarth QGIS plugin

OSM-3D

FOSSGIS 2011: Vergleich von Open Source Virtual Globes

Mittlerweile gibt es mehrere Open Source Alternativen zu Google Earth, wie z.B. Nasa World Wind Java SDK, ossimPlanet oder osgEarth. Dieser Vortrag soll eine Übersicht aktueller Open Source Virtual Globes bieten und einige Vorschläge zu erwünschten Funktionen liefern.

Präsentation

Demos:

NASA World Wind Java SDK

ossimPlanet

gvSIG 3D

osgEarth

osgEarth QGIS plugin

OSM-3D

FOSSGIS 2011: Vergleich von Open Source Virtual Globes

Mittlerweile gibt es mehrere Open Source Alternativen zu Google Earth, wie z.B. Nasa World Wind Java SDK, ossimPlanet oder osgEarth. Dieser Vortrag soll eine Übersicht aktueller Open Source Virtual Globes bieten und einige Vorschläge zu erwünschten Funktionen liefern.

Präsentation

Demos:

NASA World Wind Java SDK

ossimPlanet

gvSIG 3D

osgEarth

osgEarth QGIS plugin

OSM-3D

FOSSGIS 2011: Webgis mit QGIS und GeoExt

Neues vom QGIS Server

Der Vortrag zeigt die Fortschritte von QGIS Server auf, illustriert auch anhand von Beispielen aus der Praxis. QGIS Server kann neu .qgs Projektfiles aus dem Desktop-GIS-Bereich als zentrale Konfigurationsdatei von Webdiensten (derzeit nur WMS) verwenden. Das bietet verschiedene Vorteile:

  • Desktop-GIS, Web-GIS und WMS aus der gleichen Konfigurationsdatei
  • kein manuelles Editieren von .map-Files - auch Mapserver-Laien können nun sehr einfach Webdienste erstellen
  • Übernahme von Druck-Layouts für das Drucken im Web (derzeit in Arbeit)
  • Verwendung der neuen Label-Engine und der erweiterten Symbolisierungsmöglichkeiten aus der neuen Symbology-Engine

Die Client-Komponente wurde mit GeoExt (OpenLayers, ExtJS,GeoExt) realisiert. Es werden soviele Konfigurationen wie möglich aus dem Desktop-GIS-Bereich in den Web-GIS-Bereich übernommen, wie z.b. der Projektname, die Attributdatenbehandlung (Spaltenunterdrückung, Spaltenaliases, etc.), das Selektierbarmachen von Layern, sowie das Verwenden bereits vordefinierter Drucklayouts.

Wo möglich wurde der bestehende WMS Standard verwendet, wo nötig, wurden Erweiterungen im WMS-Protokoll vorgenommen, vorwiegend beim Drucken, aber auch bei den getFeatureInfo und getCapabilities Requests.

Der Vortrag zeigt produktive Beispiele aus dem GIS der Stadt Uster und zeigt welche Arbeitsschritte auf dem Server und dem Client notwendig sind, um ein QGIS-Projekt ins Web zu bringen.

Präsentation

FOSSGIS 2011: Webgis mit QGIS und GeoExt

Neues vom QGIS Server

Der Vortrag zeigt die Fortschritte von QGIS Server auf, illustriert auch anhand von Beispielen aus der Praxis. QGIS Server kann neu .qgs Projektfiles aus dem Desktop-GIS-Bereich als zentrale Konfigurationsdatei von Webdiensten (derzeit nur WMS) verwenden. Das bietet verschiedene Vorteile:

  • Desktop-GIS, Web-GIS und WMS aus der gleichen Konfigurationsdatei
  • kein manuelles Editieren von .map-Files - auch Mapserver-Laien können nun sehr einfach Webdienste erstellen
  • Übernahme von Druck-Layouts für das Drucken im Web (derzeit in Arbeit)
  • Verwendung der neuen Label-Engine und der erweiterten Symbolisierungsmöglichkeiten aus der neuen Symbology-Engine

Die Client-Komponente wurde mit GeoExt (OpenLayers, ExtJS,GeoExt) realisiert. Es werden soviele Konfigurationen wie möglich aus dem Desktop-GIS-Bereich in den Web-GIS-Bereich übernommen, wie z.b. der Projektname, die Attributdatenbehandlung (Spaltenunterdrückung, Spaltenaliases, etc.), das Selektierbarmachen von Layern, sowie das Verwenden bereits vordefinierter Drucklayouts.

Wo möglich wurde der bestehende WMS Standard verwendet, wo nötig, wurden Erweiterungen im WMS-Protokoll vorgenommen, vorwiegend beim Drucken, aber auch bei den getFeatureInfo und getCapabilities Requests.

Der Vortrag zeigt produktive Beispiele aus dem GIS der Stadt Uster und zeigt welche Arbeitsschritte auf dem Server und dem Client notwendig sind, um ein QGIS-Projekt ins Web zu bringen.

Präsentation

FOSSGIS 2011: Webgis mit QGIS und GeoExt

Neues vom QGIS Server

Der Vortrag zeigt die Fortschritte von QGIS Server auf, illustriert auch anhand von Beispielen aus der Praxis. QGIS Server kann neu .qgs Projektfiles aus dem Desktop-GIS-Bereich als zentrale Konfigurationsdatei von Webdiensten (derzeit nur WMS) verwenden. Das bietet verschiedene Vorteile:

  • Desktop-GIS, Web-GIS und WMS aus der gleichen Konfigurationsdatei
  • kein manuelles Editieren von .map-Files - auch Mapserver-Laien können nun sehr einfach Webdienste erstellen
  • Übernahme von Druck-Layouts für das Drucken im Web (derzeit in Arbeit)
  • Verwendung der neuen Label-Engine und der erweiterten Symbolisierungsmöglichkeiten aus der neuen Symbology-Engine

Die Client-Komponente wurde mit GeoExt (OpenLayers, ExtJS,GeoExt) realisiert. Es werden soviele Konfigurationen wie möglich aus dem Desktop-GIS-Bereich in den Web-GIS-Bereich übernommen, wie z.b. der Projektname, die Attributdatenbehandlung (Spaltenunterdrückung, Spaltenaliases, etc.), das Selektierbarmachen von Layern, sowie das Verwenden bereits vordefinierter Drucklayouts.

Wo möglich wurde der bestehende WMS Standard verwendet, wo nötig, wurden Erweiterungen im WMS-Protokoll vorgenommen, vorwiegend beim Drucken, aber auch bei den getFeatureInfo und getCapabilities Requests.

Der Vortrag zeigt produktive Beispiele aus dem GIS der Stadt Uster und zeigt welche Arbeitsschritte auf dem Server und dem Client notwendig sind, um ein QGIS-Projekt ins Web zu bringen.

Präsentation

FOSSGIS 2011: Neue Entwicklungen und Features vom Quantum GIS Projekt

Das QGIS Projekt hat zum Ziel, ein plattformunabhängiges, einfach zu bedienendes und offenes Desktop GIS zu entwickeln. Im vergangenen Jahr hat die Aktivität in der QGIS-Community erneut zugenommen. Seit der letzten FOSSGIS Konferenz in Osnabrück hat sich QGIS wieder enorm weiterentwickelt. Sucht man sich (aus der Liste der svn commits) alle Neuerungen des letzten Jahres heraus, so kommt man auf eine Liste, die den Rahmen dieses Artikels bei weitem sprengen würde. Daher stellen wir im Rahmen des Vortrags lediglich eine kleine Auswahl der Entwicklungen der aktuellen und der kommenden Versionen vor.

Präsentation

FOSSGIS 2011: Neue Entwicklungen und Features vom Quantum GIS Projekt

Das QGIS Projekt hat zum Ziel, ein plattformunabhängiges, einfach zu bedienendes und offenes Desktop GIS zu entwickeln. Im vergangenen Jahr hat die Aktivität in der QGIS-Community erneut zugenommen. Seit der letzten FOSSGIS Konferenz in Osnabrück hat sich QGIS wieder enorm weiterentwickelt. Sucht man sich (aus der Liste der svn commits) alle Neuerungen des letzten Jahres heraus, so kommt man auf eine Liste, die den Rahmen dieses Artikels bei weitem sprengen würde. Daher stellen wir im Rahmen des Vortrags lediglich eine kleine Auswahl der Entwicklungen der aktuellen und der kommenden Versionen vor.

Präsentation

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