Inlined templates usage

[crimaniak]

This issue to share my experience of compileHTMLDietFileString() usage for diet templates embedded to code. There are two problems: file name required and incorrect line number when error is found. To fix it I created inlineDiet.d:

module inlineDiet;

struct InlineDiet
{
	string file;
	int line;
	string tpl;
}

template diet(string tpl, string file=__FILE__, int line=__LINE__)
{
	enum diet = InlineDiet(file, line, tpl);
}

template compileInline(InlineDiet tpl, ARGS...)
{
	import std.array : replicate;
	import diet.html;
	
	enum string file = tpl.file~"t";
	enum string eTpl = ("\n".replicate(tpl.line-1)~tpl.tpl);
	
	alias compileInline = compileHTMLDietFileString!(file, eTpl, ARGS);
}

I add "t" to the end of current file so if template included from some component.d it will be visible to diet-ng library as component.dt file. To fix line number template is prepended by required amount of new line symbols (requirement for correct work: opening quote of template string must be on the same line as diet() template call). So now I can create simple 1-file components like this:

class ManagerMainPage : BasicManagerPage
{
// ...

// controller

	override void doContent()
	{
		client = engine.clients[registrator.getLoggedUser().clientId];
		auto page = this;
		auto stats = getStats();
		
		output.compileInline!(tpl, page, stats);
	}
	
// view
	
	enum tpl = diet!`
extends manager/page

block content
	h2 Manager page
	table
		tr
			td Organization: 
			td #{page.client.name}
		tr
			td Users:
			td #{stats["users"]}
		tr
			td Sites:
			td #{stats["sites"]}
		tr
			td Devices:
			td #{stats["devices"]}
`;	
}

I think it will be useful to add something like inlineDiet.d to library (or modify compileHTMLDietFileString to fix these issues) because every who will use compileHTMLDietFileString() will face same problems.