Special characters in c.draw "text" with mini_magick (rails)

Question

I am having quite a bit of trouble getting mini_magick to draw text that contains quotes, double quotes, etc. on an image. I have tried various modifications on c.draw to no avail. What is the best way to escape these characters so that c.draw will display them without an error?

error: non-conforming drawing primitive definitionm'`

produced by

 c.draw "text 8,8 'I'm'" 

Including other special character such as é will result in an error as well. I would like to be able to accept text strings from users as input, therefore the need for Unicode compatibility.

Answer 1

Did you see...

• ...these usage examples "Drawing Special Characters in the Text String" and
• ...this forum thread: "Trouble with quotes in Bash scripts"

?

In any case, the following works for me on the commandline:

convert \
   -size 500x100 xc:none \
   -box yellow \
   -pointsize 72 \
   -gravity center \
   -draw "text 8,8 '  \'I\'m\'  '" \
   -trim \
   +repage \
    special-chars.png

and produces this:

For more complicated text drawing requirements, you are strongly advised to circumvent all the escaping by writing your drawing commands into a separate *.mvg (Magick Vector Graphic) file. For example with this content in 1.mvg:

 text 8,8 "öäü ß ÄÖÜ é"

and this command:

convert \
   -size 250x100 xc:none \
   -box yellow \
   -pointsize 72 \
   -gravity center \
   -draw @1.mvg \
   -trim \
   +repage \
    special-chars.png

you'll get

Or even, with 2.mvg:

push graphic-context
 viewbox 0 0 600 100
 push graphic-context
   fill 'orange'
   rectangle 0,0 600,100
 pop graphic-context
 push graphic-context
   fill 'white'
   font Palatino-Roman
   font-size 48
   stroke-width 2
   gravity SouthEast
   text 8,8 "äöü ß ÄÖÜ é"
 pop graphic-context
 push graphic-context
   fill 'green'
   rectangle 10,10 300,90
 pop graphic-context
 push graphic-context
   fill 'red'
   font Palatino-Bold-Italic
   font-size 28
   stroke-width 1
   text 18,40 "€ ¥ © ℉ ậ ḁ å ǎ à ç ë ĵ"
 pop graphic-context
pop graphic-context

and this command:

convert 2.mvg 2.png

you can get: