Hi, On 11.10.2012 21:26, Tom MacWright wrote:
* Filtering the API endpoints, so that POI editors don't have to sift through road data, and so on.
There is a relatively arcane search function in the API that has gon through a series of disabling stages - initially you could do a key/value search but not limit to area; later I believe that was limited to key-only search, and now it doesn't work at all (something like that).
Good and powerful replacements exist in JXAPI and Overpass; both have the advantage that they can be installed by people on their own machines without having to put the whole rails port in place. Due to the sychronisation delay, both services might incur a higher percentage of version conflicts when used in an editor (but then again, if the editor loads and uses the data for 10 minutes then the additional minute won't change much). Yes, these systems are different systems, but on the other hand it is quite possible that we'll separate the API database into a r/w core and a read-only mirror some day soon, satisfying read responses from a replicated database in order to take load off the r/w core - that would then be two systems as well. So the difference isn't that big perhaps.
Care must be taken to limit everything that goes via the central API to editing - that's why we like to call it the "editing API". It is not meant to be a "make interesting queries API" like JXAPI/Overpass are.
Doing filtering for an editor, and doing it right, is very difficult and will require intense analysis of existing data to get an idea of how things are interconnected. A POI editor that requests everything with amenity=* needs to receive the building (and its nodes) tagged amenity=restaurant; the fact that one of the building nodes is also part of a highway=steps that links the building to the nearest street must be made known to the editor lest it allows the user to move the building node and thereby, unknowingly, distort the staircase, stuff like that.
If you want to design API endpoint filtering mechanisms you will have to think: What is the stupidest thing an editor writer could do with this? And then assume that someone writes an editor that does just that... and hopefully find ways to reduce the impact of such.
Bye Frederik -- Frederik Ramm ## eMail frede...@remote.org ## N49°00'09" E008°23'33" _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev
