[Neo4j] Neo4j-Rails and Ext-JS
Hi, I'm working on a project for using Neo4j as a database for JRuby-based Rails application. I found a good example here: http://github.com/maxdemarzi/neo4j-rails-example and I was able to start developing my application. However, I have another requirement that needs to implement the rails application using Ext-JS library. I know that the plugin ext_scaffold is helpful in generating resources based on Ext-JS, however, I tried this but no success. Neo4j-Rails removes the dependency on ActiveRecord ad replaces it with Neo4J as a database, while the ext-scaffold plugin requires ActiveRecord. Any help on this? Thank you in advance. Regards, Ahmed Abdelsalam ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo4j] Indirection
Guys, I'm trying to grokk the code. In a couple of places, there are indirections that I don't understand. Like EmbeddedGraphDatabase, which is, as far as I can see, mostly a thin wrapper around EmbeddedGraphDatabaseImpl. Why is this? Andrés ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Indirection
On Sat, Oct 30, 2010 at 12:51 PM, Andres Taylor andres.tay...@neotechnology.com wrote: Guys, I'm trying to grokk the code. In a couple of places, there are indirections that I don't understand. Like EmbeddedGraphDatabase, which is, as far as I can see, mostly a thin wrapper around EmbeddedGraphDatabaseImpl. Why is this? Andrés I second that. It isn't like there is a factory in EmbeddedGraphDatabase that will provide different implementations of something based on the Config (besides, the read-only vs the full r/w db issue is handled differently). The EmbeddedGraphDatabaseImpl field is hardwired there. I can only assume this was supposed to (or will?) augment the GraphDatabaseService interface with operations other that the EmbeddedGraphDatabaseImpl ones, given that the latter does not implement that. I also have difficulty grasping the EventConsumers concept. They are created in the XaConnection only to be stored in the NioNeoDbPersistenceSource.NioNeoDbResourceConnection and then used to forward calls about primitives. Why is that level of abstraction necessary? I think it would be cleaner and without loss of extensibility for the ResourceConnection to forward directly to the XaConnection. But I admit there are many things happening there, I may be missing something. cheers, CG ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Neo4j-Rails and Ext-JS
Hi! I think you should try asking over here: http://groups.google.com/group/neo4jrb /anders 2010-10-30 09:19, Ahmed Abdelsalam skrev: Hi, I'm working on a project for using Neo4j as a database for JRuby-based Rails application. I found a good example here: http://github.com/maxdemarzi/neo4j-rails-example and I was able to start developing my application. However, I have another requirement that needs to implement the rails application using Ext-JS library. I know that the plugin ext_scaffold is helpful in generating resources based on Ext-JS, however, I tried this but no success. Neo4j-Rails removes the dependency on ActiveRecord ad replaces it with Neo4J as a database, while the ext-scaffold plugin requires ActiveRecord. Any help on this? Thank you in advance. Regards, Ahmed Abdelsalam ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Moving a DB from one machine to another...
Hi Axel, GeoJSON and other GIS formats are planned to be supported in Neo4j Spatial. In fact to support export to GeoJSON on the current code would be very easy, I believe. I hope to get 'round to it soon. However, should you want to give it a try now, I would be more than willing to give advice and pointers. Regards, Craig On Oct 29, 2010 10:44 PM, Axel Morgner a...@morgner.de wrote: GraphML, not KMK, of course. Maybe I wrote this because I'm looking for KML and geoJSON export/import for neo4j data myself. On Fri, 29 Oct 2010 21:49:04 +0200, Peter Neubauer peter.neuba...@neotechnology.com wrote: Hi there, yes, the Neo4j Admin tool (we hope to package it in the next milestone) includes GraphML export/import. Besides, Alex is right, file copy on a clean shut down DB works just fine. For hot production use, you can choose Online Backup (http://wiki.neo4j.org/content/Online_Backup) or the upcoming HA to several slaves (part of the next milestone, too, still not totally finished testing). Would anything of this work for you? Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Fri, Oct 29, 2010 at 9:18 PM, Axel Morgner a...@morgner.de wrote: Hi Chris, moving a neo4j db as an archived directory between different machines is fine. Normally, there's no need to remove any files from within the neo4j directory. Just make sure to archive the db while it's completely shut down. And take care of the access rights the files and the containing directory have. I had some issues with that when moving between a Windows and a Linux machine. Personally, I use 7-zip [1] on Windows and p7zip [2] on Unix as it has the highest compression rates. In addition, there might be other ways to import/export data, f.e. the KML export contained in the webadmin tool. Axel [1] http://www.7-zip.org/ [2] http://p7zip.sourceforge.net/ On Fri, 29 Oct 2010 12:02:02 -0700, Chris Diehl cpdi...@gmail.com wrote: Hi All, I have a neo4j DB on my laptop that I need to share copies of with others. As a first shot I tar'ed and ziped up the contents of the DB directory and gave it to my colleague (MacBook Pro - Windows laptop). Initially he got errors when trying to access it. So on a whim, he deleted all the files with 'log' in their name. Then, after some complaints about needing to recover, all seemed well. I'm wondering if there is a more principled way of moving a DB from one machine to another short of this hack or going through a GraphML export/import sequence. Any suggestions? Chris ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Neo4j Spatial question
Hi Axel, I was away on a trip for a couple of days and did not see this discussion until now. I see several people have had good advice for you already. I think I can add to the discussion with some suggestions. Your original description says two things of interest, there is a GeoJSON document for all countries (as multi-polygons) and there is an existing neo4j database of all CMS data. I'm not sure what you mean by CMS data? Is this an unrelated content management system, and so you are only saying that you have exerience with neo4j in general, or is this data you wish to use in a spatial context (together with the world map)? In the former case, I guess we are only talking about a GeoJSON importer, in the later we are talking about using Neo4j Spatial to expose spatial information in your existing database, which is a good use case for Neo4j Spatial, so would be good to do. Either way, I think the job is not too big. For the GeoJSON importer, you could write a generic importer supporting the full GeoJSON spec, or you could write one specific to your case of only processing multi-polygons for countries. Another factor to consider, if you model your importer on the code in the shapefile importer, you will create a database structure somewhat reminiscent of postgis, with each geometry saved as a WKB blob in a node of the database. In this case the primary use of Neo4j is for the RTree index. However, I personally think it would be nicer (better) to store the world-map as a single connected graph, so that countries that share boarders actually share the nodes along those boarders. Our OSMImporter for Open Street Map maintains the OSM graph in Neo4j, as well as exposes individual geometries for those tools that require them (eg. renderers). You could do a similar thing if you had a data source that contained that topology. Normal GeoJSON, however, does not, since it describes each feature or geometry as a separate object, with no spatial relationship to any other object. Is GeoJSON the main data source, or can you get a more topologically connected data source from polymaps? So, to summarize the options: - Write a plain GeoJSON importer that imports to individual WKB geometries - very simple, could even base on a raw JSON library and write a small mapping layer for your Geometries using JTS, or you could use a GeoJSON library like the GeoTools one already suggested - Write your own new data model, maintaining connectivity to your other data (if that exists) and a 'better' world map graph. - If you do not have access to a fully connected world map of countries, perhaps using OSM data for this is an alternative to your current data source. Regards, Craig On Fri, Oct 29, 2010 at 3:30 PM, Axel Morgner a...@morgner.de wrote: Thanks a lot, I'll give it a try soon. Am 29.10.2010 08:58, schrieb Jan Boonen: Hi Axel, The FeatureJSON class of GeoTools ( http://docs.geotools.org/latest/javadocs/org/geotools/geojson/feature/FeatureJSON.html ) should be able to do the work. Look at the code example in the Javadocs to see if this is what you need. In order to connect it to neo4j, you could use the code from the Shapefile importer. Cheers, Jan On 28-10-2010 17:24, Peter Neubauer wrote: some example on reading in a FeatureColllection from GeoJSON, but the ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user -- Axel Morgner Creative Solutions - Software Engineering GUI UX Design - Project Management c/o inxire GmbH Hanauer Landstr. 293a 60314 Frankfurt Germany Phone +49 151 40522060 E-mail a...@morgner.de Web http://morgner.de ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
