[Xastir-Dev] proposed method of doing canoncial shapefile DBF attributes support

[Alan Crosswell]

Get me the pointer, but if it ain't KISS, it ain't gonna get implemented any 
time soon.
/a

Gerry Creager (N5JXS) wrote:
> Woohoo!  Metadata!  In a consistent fashion!
> 
> There are standards we can tap for metadata, including GML instead of 
> awk syntax, which are reasonably mature and don't require defining our own.
> 
> If there's interest, I can get the OGC GML references and making them 
> available; they're on the OpenGIS.org site, too.
> 
> One thing I'd love to see is Xastir-2 OGC compliant for Location-Based 
> Services, among other areas.
> 
> gerry
> 
> Alan Crosswell wrote:
> 
>> OK, so I guess attachments get broken.  Here it is inline:
>>
>> Use a metadata file for each map that translates map-specific fields into
>> canonical fields.  When the metadata file is missing, guess at which one
>> of several pre-defined metadata definitions to use based on the dbf
>> "signature" (as the code does currently).
>>
>> Let's try a sample file (use Tiger/line since they are the most 
>> complicated):
>>
>> Use awk subset syntax.  Implement patterns using the pcre(3) library.
>> pattern { action}
>>
>> Action grammar is:
>> <attr> := "width" | "color" | "name" | "filled" | "pattern"
>>           | "display_level" | "label_level"
>> <attr_set> := <attr> "=" value
>> <op>   := "next"   # like awk, to end pattern search
>> <stmt> := <attr_set> | <op>
>> <stmt_list> := <stmt_list> ";" <stmt> | <stmt>
>> <action> := <stmt_list>
>>
>> Read DBF fields and pass them to this function as
>> <field>=value
>>
>> Sample file for Tiger/Line:
>> # see tig2aprs.c cfccrange() for related examples.  See Tiger/Line
>> # technical documentation for complete list of codes.
>> # set defaults:  empty pattern matches everything.
>> {key=""; width=1; color=black; name=""; filled=0; pattern=solid;
>>  display_level=8192; label_level=32}
>> # set the search key to be the Tiger/Line ID.  Not currently used.
>> /^TLID=\(.*\)$/ {key=$1}
>> # set the label to be the Feature Name
>> /^FENAME=United States Highway\(.*\)$/ {label="US $1"};
>> /^FENAME=State Highway\(.*\)$/ {label="State $1"};
>> /^FENAME=State Route\(.*\)$/ {label="SR $1"};
>> /^FENAME=\(.*\)$/ {label=$1}
>> # Census Feature Class Code
>> # A: roads
>> /^CFCC=A1/ {lanes=4; color=brown}
>> /^CFCC=A2/ {lanes=3; color=black}
>> /^CFCC=A3[1-6]/ {display_level=256; next}
>> /^CFCC=A3[7-8]/ {display_level=128; next}
>> /^CFCC=A3/ {lanes=2; color=black}
>> /^CFCC=A4/ {display_level=96; label_level=16; color=gray35; lanes=1}
>> /^CFCC=A5/ {lanes=2; color=gray35; display_level=64}
>> /^CFCC=A65/ {lanes=2, color=black, pattern=dashed; next}
>> /^CFCC=A6[^5]/ {color=gray35; display_level=64; next}
>> /^CFCC=A7[12]/ {lanes=1; color=red; pattern=dashed; display_level=64; 
>> next}
>> /^CFCC=A7[03-9]/ {lanes=1; color=gray35; pattern=dashed; 
>> display_level=64; next}
>> # need to implement these:
>> # B: railroads
>> # C: transmission lines
>> # D: landmarks
>> # E: physical featuers
>> # F: county boundaries
>> # (G not used by census;  tig2aprs uses for special maps)
>> # H: hydrography
>> /^CFCC=H0/ {lanes=0; color=Steelblue;}
>> /^CFCC=H02/ {pattern=dashed; next}
>> /^CFCC=H[1-6]2/ {lanes=1; pattern=dashed; next}
>> /^CFCC=H[1-6][013-9] {lanes=1; next}
>> /^CFCC=H7/ {display_level=0; label_level=0; next}
>> /^CFCC=H8/ {color=steelblue; lanes=1}
>> /^CFCC=H81/ {color=white; next}
>>
>>
>> Alan Crosswell wrote:
>>
>>> What do you think:
>>>
>>>
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>>
>>
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> 
>