Sketch's current SVG import and export features

[Markus Rechtien]

I tried to figure out current status of the sketchs internal
import and export capabilities.

All points regard the sketch-0.6.16pre2 version.

#
# SVG-Import features currently supported by sketch:
# (see Plugins/Filters/svgloader.py)
#

    Color attributs:
        - NAMED COLORS (view SVG specs at w3.org)

    Line attributs:
        - LINE JOIN BEHAVIOUR (miter, round, bevel)
        - LINE END PROPERTY (none, butt, round, square)
    
    Transformations:
        - Attributs (matrix, scale, translate, rotate, skewX, skewY)
        
    SVG Attributs:
        - VIEWBOX
        - HEIGHT
        - WIDTH
        
    Style Attributs (only CSS synthax works):
        - FILL (empty, solidcolor, stroke)
        - STROKE (none, stroke, stroke-width, color, stroke-linejoin, 
stroke-linecap)
        - FONT (font-family, font-size, text-anchor)
    
    Circle:
        - ATTRIBUTS (id, cx, cx, cy, r, style)

    Elipse:
        - ATTRIBUTS (id, cx, cy, rx, ry, style, x, y, width, height)
    
    Polyline:
        - ATTRIBUTS (id, points, style)
    
    Polygone:
        - ATTRIBUTS (id, points, style)

    Image:
        - ATTRIBUTS (id, xlink:href, x, y, width, height, style)
    
    Text:
        - ATTRIBUTS (id, x, y, text, style)
    
    Paths:
        - ATTRIBUTS (all except eliptical arc)

    - Group (g) Tag


#
# Missing or incomplete import features:
#

    - Paths (eliptical arc)
    - Pathtext
    - Clipping and masking
    - Images from data URLs
    - Arrows (marker)
    - Defs tag (has to be rewritten)
    - Use tag (has to be rewritten)
    - (User) coordinates / units (has to be rewritten)
    - Tests
    - Filter
    - SVG fonts


#
# SVG-Export features currently supported by sketch: 
# (see Plugins/Filters/svgsaver.py)
#

Currently Sketch writes the following styleinformations ...

    Line attributs:
        - LINE PATTERN SOLID
        - LINE PATTERN DASHED (uses fixed dasharray value)
        - LINE WIDTH / STROKE WIDTH
        - LINE JOIN BEHAVIOUR (miter, round, bevel)
        - LINE END PROPERTY (none, butt, round, square)
        - LINE ENDINGS WITH ARROW AT THE START OR END (fixed size, wrong 
orientation)

    Fill attributs:
        - FILL PATTERN (none, solidcolor, axial and radial gradient [basic 
capabilities])

    Font properties:
        - FONT NAME IS COMPARED TO LOCAL FONTMAP (otherwise postscriptname is 
used)
        - FONT SIZE

    Gradient properties:
        - LINEAR GRADIENT INCLUDING STOPS, ROTATION, ANGLE, PATTERN POSITION
        - RADIAL GRADIENT INCLUDING STOPS, RADIUS

    Path elements:
        - STYLE ATTRIBUTS
        - OPEN / CLOSED
        - BEZIER CURVES
        - POLYLINES
        -> CURRENTLY RECTANGLES ARE SAVED AS PATHS TOO

    Text elements:
        - ATTRIBUTS (style, transform)

    Grouping:
        - BEGIN OR END A GROUP

    Document properties:
        - FIXED XML HEADER FORMAT (uses ISO-8859-1 encoding - 
                    sketch currently lacks of unicode support)
        - DOCUMENT PROPERTIES (width, height, transform)


#
# Missing export features:
#
    - Pathtext
    - Clipping and masking
    - Images
    - Conical gradients
    - Arrows (marker)
    - Tests
    - Filter
    - SVG fonts