I would like to use xmlstarlet to find the element of an xml file which contains the attribute inkscape:label="L2" and set the its attribute "style" to the value "display.inline". The difficulty is that the attribute "style" may or may not already be defined.
I am currently using this command:
xmlstarlet edit --inplace --update "//*[@inkscape:label=\"L2\"]/@style" --value "display:inline" ex.svg
It will work if the attribute style is already defined
// It works on this
<g inkscape:groupmode="layer"
id="layer2"
inkscape:label="L2"
style="display:none">
but it will not work otherwise:
// Does not work
<g inkscape:groupmode="layer"
id="layer2"
inkscape:label="L2">
I also defined a command which enables to add the desired attribute:
xmlstarlet ed --insert "//*[@inkscape:label=\"L2\"]" --type attr -n style -v "display:inline" ex.svg > output.svg
Unfortunately, if the attribute already exists, a second one will be added:
// The element now contains two attributes style
<g inkscape:groupmode="layer"
id="layer2"
inkscape:label="L2"
style="display:none"
style="display:inline">
Is there a way to create the attribute if it does not exist and to edit it otherwise?
You can use both the --update and --insert, but only insert when the element does not have a style attribute (not(@style)).
Example:
xmlstarlet edit --inplace --update "//*[@inkscape:label=\"L2\"]/@style" --value "display:inline" --insert "//*[@inkscape:label=\"L2\"][not(@style)]" --type attr -n style -v "display:inline" ex.svg