[Question] Inject content after template render

[nd2s]

Currently I am embedding SVG icons by calling a function {%= p.SVGSymbol("svg/icon/close.svg") %} that creates a SVG <use xlink> tag and remembers the symbol being used. And at the end of the template I embed the automatically generated SVG definitions (so that only icons that are actually used are embedded).

I know need to insert the sprite at the beginning of the content - before I know what icons I need to embed.

What would be the best way to achieve that without having to render all templates twice for every call?

[valyala]

Just split the original template func into two template funcs:

1. The first one - p.PageContents - calls p.SVGSymbol, which remembers the content required for the embedded SVG inside p.
2. The second one - p.SVGDefinitions - generates SVG definitions for the remembered SVG symbols from the first template.

Then the code would look like:

pageContents := p.PageContents()
svgDefinitions := p.SVGDefinitions()
resultingText := svgDefinitions + pageContents

This code isn't optimal from memory allocations point of view, but it calls p.PageContents only once.