Setting default paragraph style without user interaction - ckeditor

Question

I am trying to set the default style applied to the P elements that are automatically created when a user enters the blank editing area. I've spent many hours searching for an answer but have not found anything that works. The requirements are:
Style has to be inline, no stylesheet
No user interaction, no format/style plugin to click
When the user clicks in the editing area and starts typing, I want the style to be applied and visible automatically. Surely there is a way to accomplish this?
The closest I have gotten is by using the htmlFilter, like this :
p_rule = {
elements : {
p : function(element) {
if (element.attributes.style === undefined) {
element.attributes.style = "color: #0000ff;";
}
}
}
};
ev.editor.dataProcessor.htmlFilter.addRules(p_rule);
But the new style is not automatically visible.
It does become visible if the user goes into source editing mode and back to WYSIWYG but I want it to be automatic.
I tried using updateElement() in the filter function, but it does not work and creates infinite recursion:
p_rule = {
elements : {
p : function(element) {
if (element.attributes.style === undefined) {
element.attributes.style = "color: #0000ff;";
CKEDITOR.instances['editor1'].updateElement();
}
}
}
};
ev.editor.dataProcessor.htmlFilter.addRules(p_rule);
(I guess updateElement() triggers the filter)
If I use setData(getData()) from an event I can strangely get the textarea to update with the changes the filter applied, for example:
CKEDITOR.instances['editor1'].on('blur', function() {
CKEDITOR.instances['editor1'].setData(CKEDITOR.instances['editor1'].getData());
});
But that too requires user interaction. Using the "change" event creates recursion.
I am new at CKEditor and obviously I'm missing something on how the filter works in relation to what is currently being displayed in the textarea.
Any CKEditor guru out there? Help!
Thanks

Answer 1

I really advise not to go this way. You'll find yourself fighting with countless issues, like what if you copy&paste, what if you change format to h1 and then back, what if you create a list item and then convert that into a paragraph, etc. etc. There are really dozens of those. You'd need to rewrite half of the editor.
The way to handle this in CKEditor 4 is to rethink this:
Style has to be inline, no stylesheet
Inside CKEditor you clearly need to use a stylesheet. I presume though that you want the inline styles in the output. So what I would propose is to:
Write htmlFilter rule which adds this style to every paragraph.
Write dataFilter rule which removes this style from every paragraph.
The second rule is needed so if you save the data and then load it back to the editor, the styles do not pollute it.
PS. CKEditor 5 will separate data model from rendering (the view) so you'll be able to render paragraph as you wish without affecting how other features interact with it. Read more about CKEditor 5 in this article.