Hi
Please have a look at these reference articles:-
Link:- http://blogs.adobe.com/contentmanagement/tag/custom-richtext/
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1. Traverse to your component node (/apps/blog/components/content/demo) and create a child node of type cq:ClientLibraryFolder and name it clientlib.
2. Create a folder under clientlib and name it css.
3. Create a file under css folder and name it static.css
4. Open your static.css and paste the below code in it. Save.
5. Traverse to your components fieldConfig node and create a new property for fieldConfig with name as externalStyleSheets and value as the path to the static.css that we created in last few steps .
6. Traverse to your rteconfig/rtePlugins/styles node (/apps/blog/components/content/rteconfig/rtePlugins/styles) and create a child node of type cq:WidgetCollection and name it styles (yes the name is same as parent nodes name).
7. Create a child node under this styles node (from step 1 above /apps/blog/components/content/rteconfig/rtePlugins/styles/styles): type of child node nt:unstructured and name it strikethrough
8. Create following properties for this strikethrough node:
Property 1:
name: cssName
value: strikethrough
Property 2:
name: text
value: StrikeThrough
Read the post to get step by step solution to your problem.
Link:- https://docs.adobe.com/docs/en/cq/5-6-1/administering/configuring_rich_text_editor.html#Styles (Tables and Table Cells)
//Style selector box in either the Cell properties or Table properties dialog
I hope these article will surly help you.
Thanks and Regard
Kautuk Sahni