Please add this to the readme :)
> On 5 Jun 2020, at 23:19, Hernán Morales Durand <hernan.mora...@gmail.com> > wrote: > > > > El vie., 5 jun. 2020 a las 9:27, Baveco, Hans (<hans.bav...@wur.nl > <mailto:hans.bav...@wur.nl>>) escribió: > Well, it appears that simple direct downloading does not download the real > shapefile. Taking care to actually get a shapefile, the result loads without > problems. > > ne_110m_populated_places.shp is a PointShape with 243 shapes (points). If you > display it on a Form (#displayMorphic) you won’t see much (243 hardly visible > dots). > > > > > I checked and my previous download method was completely wrong. Now switching > from ZnEasy to ZnClient to download and it works nicely: > > | shpE legend urlRoot urlESRIFilePrefix urlESRIFileShp urlPath response > fileRef | > > " Download Shapefile resources " > urlRoot := > 'https://github.com/nvkelso/natural-earth-vector/blob/master/110m_cultural/ > <https://github.com/nvkelso/natural-earth-vector/blob/master/110m_cultural/>'. > urlESRIFilePrefix := 'ne_110m_populated_places'. > urlESRIFileShp := urlESRIFilePrefix , '.shp'. > urlPath := urlRoot , urlESRIFilePrefix. > > #('.shx' '.dbf' '.shp' '.cpg' '.prj') do: [ : ext | > ZnClient new > url: (urlPath , ext) asZnUrl; > queryAt: 'raw' put: 'true'; > numberOfRetries: 2; > enforceHttpSuccess: true; > downloadTo: urlESRIFilePrefix , ext; > get ]. > > " Load and display it in Morphic " > shpE := ShapeEnsemble fromFile: urlESRIFileShp. > " List data fields " > shpE dataFields inspect. > " List all shape records " > shpE shapeRecords inspect. > " Set the current attribute " > shpE attribute: 'NAME'. > > legend := ColorLegend mapValuesToRandom: shpE valuesOfCurrentAttribute. > shpE legend: legend. > > shpE displayMorphic. > > With an application for vector graphics (Roassal?) that can read & display > the vector data we would get much nicer maps... > > > > Hans > > > > From: Baveco, Hans <hans.bav...@wur.nl <mailto:hans.bav...@wur.nl>> > Sent: vrijdag 5 juni 2020 12:44 > To: Any question about pharo is welcome <pharo-users@lists.pharo.org > <mailto:pharo-users@lists.pharo.org>> > Subject: [Pharo-users] shape file reading > > > > Hi Hernan > > > > I downloaded this shapefile directly via the browser. Indeed it won’t load, > the type of shape file returned is > > self longAt: 33 bigEndian: false -> 577660194 > > > > > > where it should have answered an Integer between 0 and 31 > > > > shapeType > > "position 32, Integer between 0 and 31, Little Endian" > > > > ^shpBytes longAt: 33 bigEndian: false > > > > > > No idea what could be the cause – apparently the header of the file (the > first 100 bytes) is not ok... > > > > Hans > > > > > > > > > > You mean some types are missing? Because I get this error when I try to read > some SHP files: "Types > 20 are not yet accounted for" > > > > I wrote this script to reproduce: > > > > | shpE legend urlRoot urlESRIFilePrefix urlESRIFileShp urlPath response > fileRef | > > " Download Shapefile resources " > urlRoot := > 'https://github.com/nvkelso/natural-earth-vector/blob/master/110m_cultural/ > <https://github.com/nvkelso/natural-earth-vector/blob/master/110m_cultural/>'. > urlESRIFilePrefix := 'ne_110m_populated_places'. > urlESRIFileShp := urlESRIFilePrefix , '.shp'. > urlPath := urlRoot , urlESRIFilePrefix. > > #('.shx' '.dbf' '.shp') do: [ : ext | > | url | > url := (urlPath , ext , '?raw=true') asZnUrl. > (response := ZnEasy get: url) isSuccess > ifFalse: [ self error: 'Cannot download file' ]. > fileRef := FileSystem disk workingDirectory / (urlESRIFilePrefix , ext). > fileRef writeStreamDo: [ : stream | > stream nextPutAll: ((ZnByteEncoder newForEncoding: 'koi8r') decodeBytes: > response contents ) ] ]. > > > > Once downloaded: > > > > | urlESRIFilePrefix urlESRIFileShp shpE | > urlESRIFilePrefix := 'ne_110m_populated_places'. > urlESRIFileShp := urlESRIFilePrefix , '.shp'. > > " Load and display it in Morphic " > shpE := ShapeEnsemble fromFile: urlESRIFileShp. > > > > Maybe it's related with the fact they are encoded as koi8r? > > I checked with Zinc downloading first from the browser: > > > > | shpFile | > > shpFile := 'ne_110m_admin_0_countries.shp' asFileReference. > [ shpFile binaryReadStreamDo: [ : in | > (ZnCharacterEncoder detectEncoding: in upToEnd) identifier ] ] > on: ZnCharacterEncodingError > do: [ nil ]. > > > > > > Cheers, > > > > Hernán > > > > > -------------------------------------------- Stéphane Ducasse http://stephane.ducasse.free.fr / http://www.pharo.org 03 59 35 87 52 Assistant: Aurore Dalle FAX 03 59 57 78 50 TEL 03 59 35 86 16 S. Ducasse - Inria 40, avenue Halley, Parc Scientifique de la Haute Borne, Bât.A, Park Plaza Villeneuve d'Ascq 59650 France
