Saturday, 20 June 2015

GeoExt 3 Codesprint - Day 2 and 3


Day 2 and 3 of the GeoExt 3 Codesprint brought a lot of useful outcome. After the sprinters had to do a lot of discussion work on day 1 the following two sprint days could be used to implement a lot of stuff. Here is a list of tasks which were already tackled:

Investigations on an approach to use an ExtJS "Universal App" (optimized for desktop and mobile) with GeoExt components seemed very promising.

First research work for vector support in the PrintProvider class has been done.

A lot of work has been invested on the data models especially in combination with the LayerTree.

A Popup class to show georeferenced popups on the map has been implemented.

A LayerList class for mobile devices has been written.

The FeatureRenderer class has been done, including examples and tests.

A website has been setup for the project.

A lot of examples have been created. Some of them are published on the project website. Some more are following the next days.

The license had to be switched to GPLv3 because Sencha removed the FLOSS exception, which allowed us to license GeoExt under BSD before.


So all in all a really great result of the sprint! Thanks to all sprinters, who worked on this.


But the sprinters did not just work. On Thursday evening was a great social event at Braushaus Bönnsch where the sprinters could enjoy the local food and beer.



To sum it up:
The GeoExt 3 Codesprint was a big and important step for the project! A solid foundation for the future of GeoExt has been created. Stay tuned!

Last but not least a big thank you to all our sponsors. Without their input this sprint would not have been possible. And thanks to terrestris, for beeing such a great host (especially chef Till) .

Thursday, 18 June 2015

GeoExt is getting the 3

GeoExt 3 Codesprint 

Yesterday a group of GeoExt developers came together in Bonn (Germany) to set the foundation for the new GeoExt 3 which will be built upon ExtJS 6 and OpenLayers 3. In Bonn itself 9 sprinters attended on-site and one sprinter worked remotely from Greece.

The Codesprint has been sponsored by several companies and agencies (either by providing developer manpower or by money donations):

Thank you for supporting GeoExt!

Day 1 - Getting Started

After a decent warmup we had some strategic conversations before hitting the keys. First of all we defined the objectives of the sprint in order to get a kind of prioritized roadmap. After that Kai and Marc presented their work on ExtJS 6 and OpenLayers 3 which tackeled a lot of the architectural project setup (e. g. the package structure and a test suite) and even some class impementations (e.g. a MapPanel and a basic LayerTree), which were demonstrated as working examples. The sprinters agreed to use this pre-work as a good starting point for the implementation stage and therefore we merged the code of Marc and Kais work into the project master.
After that a lot of strategic discussions were done, which were very productive and necessary to get a common understanding of what we want to achieve.

Later the day we started hacking and tackled the following tasks:

The MapPanel class has been reworked to an ExtJS Component and is no more a ExtJS Panel in order to avoid overnesting, which is a first step for mobile support.

The implementation of a FeatureRenderer started and will be continued the next days.

First tests for mobile support have been done.

A script for generating example skeletons has been implemented.

Work on the print package started and will be continued the next days.

The GeoExt package (to use in Sencha Cmd architectures) is now available on remote resource.


So a lot has been done but still many more to do. Stay tuned! 



Special thanks to the "GeoExt chef Till", who supported us with an excellent soup for lunch!


Thursday, 20 March 2014

Bugfix release GeoExt v2.0.1 is available

We are pleased to announce GeoExt 2.0.1, which is the first bugfix release of the GeoExt 2-series.

This release only fixes minor issues with 2.0.0. This is what is included:

  • Fix GeoExt.Version #201
  • Use theme-switcher in examples #202
  • Made GeoExt.LayerModel extendable #203
  • Refactor sliders #204 & #205
  • Testsuite enhancements #211 & #214
  • various minor bugfixes

All users of GeoExt 2 are encouraged to update to this version. Updating should be no problem and should not break your applications built on top of GeoExt 2.

Thanks to everyone who was involved in building this version.

Friday, 25 October 2013

Finally: GeoExt 2.0.0 released

Two weeks after the first release candidate, we are happy and proud to announce the release of GeoExt 2.0.0!

Download it at https://github.com/geoext/geoext2/releases/tag/v2.0.0

GeoExt 2.0.0 is the first official GeoExt version that is built atop of OpenLayers 2.13.1 and ExtJS 4.2.1.

Read more about this release over at github, download GeoExt 2.0.0, and use it in your OpenLayers 2.13.1 and Ext JS 4.2.1 powered webpage. Do so by telling the autoloading-mechanism of Ext about GeoExt:

Ext.Loader.setConfig({
  enabled: true,
  paths: {
    GeoExt: "path/to/geoext2/src",
    Ext: "path/to/extjs/src"
  }
});


We are looking forward to your feedback on this release.


Tuesday, 15 October 2013

Announcement: GeoExt 2.0.0-rc.1 released

The GeoExt community is proud to announce the first release candidate of GeoExt 2.0.0.

Download it at https://github.com/geoext/geoext2/releases/tag/2.0.0-rc.1

GeoExt 2.0.0-rc.1 is the first official GeoExt version that is built atop of OpenLayers 2.13.1 and ExtJS 4.2.1. It has been in the making for quite a while, but most of the code comes from a code sprint in Bonn, Germany, that happened last year.

The newest major version of GeoExt wants to provide mostly the same API you know and love from the 1.x-series. It comes with support for the autoloading-mechanism of ExtJS, support for the single-file build tool of Sencha and with an exhaustive documentation that is built using the same tools as ExtJS. There are two versions of the API-docs: one has only the GeoExt-classes, while the other also has the basic Ext-classes, from which properties and methods might be inherited.

This release wouldn't have been possible without the sponsors of the above mentioned sprint. Also we want to thank the companies behind the contributors of GeoExt for supporting GeoExt development in numerous ways.

We invite you to test the release candidate! To do so, download GeoExt 2.0.0-rc.1 from (see above) and use it in your OpenLayers 2.13.1 and Ext JS 4.2.1 powered webpage by telling the autoloading-mechanism of Ext about GeoExt:

    Ext.Loader.setConfig({
        enabled: true,
        paths: {
            GeoExt: "path/to/geoext2/src",
            Ext: "path/to/extjs/src"
        }
    });

Have a look at the examples and additional information listed at the GeoExt 2 website over at github: http://geoext.github.io/geoext2/

We are looking forward to your feedback on this release.

[Edited 2013-10-16: Removed typos]

Thursday, 18 October 2012

OpenLayers 3: Invest in the web mapping future !

OpenLayers Community has initiated a call for funding in order to develop a brand new release based on the latest technogies: OpenLayers 3. If this becomes a reality, than GeoExt will also benefit of these new possibilities and would allow to develop awesome applications.
Please get in touch at ol3-funding@googlegroups.com if you’re interesting in being involved.


Saturday, 12 May 2012

GeoExt 2 - more technical details

This blog post provides more details on GeoExt 2 and Ext JS 4, focusing on technical aspects

So GeoExt 2 is a port of GeoExt 1 to Ext JS 4. The GeoExt 2 code sprint was really about porting the existing code base to Ext JS 4, redesigning, and rewriting code, only when simple adaptations were not possible.

GeoExt 2 works with Ext JS 4 only. Ext JS 3 and lower aren't supported, and won't be, obviously.

Note also that GeoExt 2 doesn't work with Sencha Touch. Sencha Touch and Ext JS 4 have similarities but their APIs are too different to write code that works with both libs. We actually did attempt to make map panel work with both Ext JS 4 and Sencha Touch, but failed.

The class system

The class system of Ext JS 4 is quite different from that of Ext JS 3. Ext JS 3 had no specific mechanism for defining classes, and had Ext.extend to define child classes. With Ext JS 4 classes are defined using Ext.define. Defining a parent class is done as follows:

Ext.define('P', {
    // prototype object
});

Defining a child class is done as follows:

Ext.define('C', {
    extend: 'P',
    // prototype object
});

In the above examples the P and C constructors are added to the window namespace. To create a class without adding a reference to it in the global namespace Ext.Class can be used. Ext.define actually uses Ext.Class internally, and most of the time you should not need to use Ext.Class.

So porting GeoExt to Ext JS 4 has required using Ext.define for every class definition – the easy part of the porting work really.

Another major change in Ext JS 4 is the way classes should be instantiated. Although using the new keyword still works (thank god!) using Ext.create is recommended. For example:

    var c = Ext.create('C');

Using Ext.create Ext JS will actually load the script containing the class if the class is not defined yet. This is called "synchronous loading" in the Ext JS 4 jargon, which means "load the class at the time it is actually needed".

The autoloader also supports "asynchronous loading". When relying on asynchronous loading, scripts are loaded earlier, in fact as soon as Ext.require is called or when classes with specific requirements (defined with "requires" in the class) are defined. Synchronous loading works with XHR while asynchronous loading works by dynamically adding script tags to the page.

The data components

The data types/components in Ext JS 4 work differently from Ext JS 3. Ext JS 4 has introduced the notion of “model”. A model, which is a class, defines a data schema. For example:

Ext.define('my.Model', {
    extend: 'Ext.data.Model',
    fields: [{
        name: 'text', type: 'string'
    }, {
        name: 'code', type: 'int'
    }]
});

This defines a data model with two fields/columns: "text" and "code". The defined model class can then be used in a store. For example:

var store = Ext.create('Ext.data.Store', {
    model: 'my.Model'
});

GeoExt 2 defines its own data models. To name a few: LayerModel, WmsCapabilitiesLayerModel, WmsDescribeLayerModel to name a few.

GeoExt 2 also defines preconfigured stores. For example GeoExt 2 includes WmsDescribeLayerStore which is preconfigured with WmsDescribeLayerModel.

As GeoExt 1, the goal of GeoExt 2's data components is to ease working with geo data and metadata in Ext JS applications. But we had to rethink and redesign things in GeoExt 2, to adapt to Ext JS 4's new architecture and concepts.

The tree components

(paragraph contributed by Andreas Hocevar) Trees have seen a complete overhaul in Ext JS 4. Instead of loaders, every node in a tree now has a store for its child nodes. While the Ext JS 4 tree is more flexible than the Ext JS 3 one when it comes to columns (the tree is a grid), there are less extension points for customizations on the node level. And GeoExt 1 did a lot of customizations on the node level. But despite these difficulties, we were able to come up with a nice API for configuring trees. Let's have a look at a tree configuration for including a WMS GetLegendGraphic image for each layer in GeoExt 1:

// custom layer node UI class
var LayerNodeUI = Ext.extend(
    GeoExt.tree.LayerNodeUI,
    new GeoExt.tree.TreeNodeUIEventMixin()
);
var tree = new Ext.tree.TreePanel({
    // apply the tree node component plugin to layer nodes
    plugins: [{
        ptype: "gx_treenodecomponent"
    }],
    loader: {
        applyLoader: false,
        uiProviders: {
            custom_ui: LayerNodeUI
        }
    },
    root: {
        nodeType: "gx_layercontainer",
        loader: {
            baseAttrs: {
                uiProvider: "custom_ui"
            },
            createNode: function(attr) {
                // add a WMS legend to each node created
                attr.component = {
                    xtype: "gx_wmslegend",
                    layerRecord: mapPanel.layers.getByLayer(attr.layer),
                    showTitle: false,
                    // custom class for css positioning
                    // see tree-legend.html
                    cls: "legend"
                };
                return GeoExt.tree.LayerLoader.prototype.createNode.call
                           (this, attr);
            }
        }
    },
    rootVisible: false,
    lines: false
});

Obviously the configuration of a custom TreeNodeUI to get additional events on the tree, which are needed by the gx_treenodecomponent plugin is a bit cumbersome. With GeoExt 2, the same tree can be achieved with a much nicer configuration:

var store = Ext.create('Ext.data.TreeStore', {
    model: 'GeoExt.data.LayerTreeModel',
    root: {
        plugins: [{
            ptype: "gx_layercontainer",
            loader: {
                createNode: function(attr) {
                    // add a WMS legend to each node created
                    attr.component = {
                        xtype: "gx_wmslegend",
                        layerRecord: mapPanel.layers.getByLayer(
                                          attr.layer),
                        showTitle: false,
                        // custom class for css positioning
                        // see tree-legend.html
                        cls: "legend"
                    };
                    return GeoExt.tree.LayerLoader.prototype.createNode.call
                              (this, attr);
                }
            }
        }]
    }
});
var tree = new GeoExt.tree.Panel({
    store: store,
    rootVisible: false,
    lines: false
});

The node (here: the root node) can be configured with plugins. Note that this is not an Ext JS 4 extension point, but one that we created in GeoExt 2. As long as your tree is a GeoExt.tree.TreePanel instead of an Ext.tree.TreePanel, and its store is configured with a GeoExt.tree.LayerTreeModel instead of the default model, there are no special configuration options needed to make the already built-in component rendering available.

Instead of having this built into our default tree view (the one the GeoExt.tree.TreePanel is configured with), we could also move it into a plugin before the final release. This decision depends on how much code the other plugins (like the ActionPlugin and RadioButtonPlugin) require, and our architecture allows us to create an extension point here any time.