Arrange Markdown Blocks

script

// Arrange blocks grouped by MD heading levels
// RV 2020-03-01 at 16:48 EST

// Uses the Arrange dialog with selected text or whole draft, if no selection.
// Overwrites the selected text with the results from this dialog, if changes.
// NOTE!
// Loops for easy change of level if Arrange is canceled or unchanged.
// Rearrange blocks or cancel level prompt, will exit loop.


main: {
	let range = editor.getSelectedRange();
	do {
		let level = SelectHeadingLevel();
		if (!level) { 
			// cancel prompt to break loop
			context.cancel('Canceled');
			break main;
		}
		let text = GetText(range);
		if (Arrange(text, level, range)) {
			// text was rearanged and draft replaced 
			break main;
		}
	} while(true);
}


function SelectHeadingLevel() {
	var p = Prompt.create();
	p.title = "Markdown Heading Blocks";
	p.message = "Use 'block mode' in 'Arrange'!...";

	var options = ["H1: #", "H2: ##", "H3: ###", "H4: ####",
  		             "H5: #####", "H6: ######"];
	var selected = ["H3: ###"];

	// single selection
	p.addSelect("s1", "Select heading group level...", options, selected, false);
	p.addButton("OK");

	if (!p.show()) {
		// Prompt 'Cancel'
		return false;
	}
	// Prompt 'OK'
	return String(p.fieldValues["s1"])[1]; // 2nd char: the number only.
}


function GetText(range) {
	// Get all text or selected text from editor
	let text = '';
	
	if (range[1] == 0) {
		text = draft.content;
	}
	else {
		text = editor.getSelectedText();
		
		// preserving whitespace at end of selection
		m = text.match(/\s+$/g);
		if (m != null) {
			endSpace = m;
		}
		text = text.trimEnd();
	}
	return text;
}


function Arrange(text, level, range) {
	let endSpace = '';
	let len = text.length;

	// insert '¶'-character at all blank lines and clean possible space/tabs,
	// to make/fake a contigous block of all text:
	text = text.replace(/\n[ \t]*\n/g, '\n¶\n');
	// Run twice to deal with multiples blank lines:
	text = text.replace(/\n[ \t]*\n/g, '\n¶\n'); 

	// remove '¶'-character above all md headings at selected levels,
	// to divide text into chapter/section blocks:
	var repl = '¶(\\n#{1,'+level+'} )';
	var re = new RegExp(repl,"g", '$1');
	text = text.replace(re, '$1');
	// text = text.replace(¶(\n#{1,3} )/g, '$1') // hardcoded at lev 3

	let processed = editor.arrange(text);
	if (processed == text) {
		// Content not changed or "Arrange" was canceled,
		return false;
	}
	
	// 'Arrange' changed and was not canceled:
	if (range[1] == 0) {
		// select all text if no inital selection:
		editor.setSelectedRange(0, len);
	}
	
	// remove all '¶'-characters from blank lines,
	// and replace selected text (or all text if no initial selection):
	editor.setSelectedText(processed.replace(/\n¶/g, '\n').trimEnd() + endSpace);
		
	if (range[1] == 0) {
		// If no initial selection,
		// reset to original position, with 0 length:
		editor.setSelectedRange(range[0], 0);
	}
	return true;
}