svgdx.xml

<svg>
  <style>text {font-weight: bold; font-size:4px}</style>
  <rect surround="#input #svgdx #output" margin="10" class="d-fill-darkgrey"/>
  <rect surround="#input #svgdx" margin="7 4" opacity="0.5" class="d-dash d-fill-cornflowerblue d-text-small" text="svgdx" text-loc="tl"/>
  <rect surround="#svgdx #output" margin="4 4" opacity="0.5" class="d-dot d-fill-green d-text-small" text="svg" text-loc="tr"/>

  <rect id="svgdx" wh="30 10" text="svgdx" class="d-fill-teal d-text-ol"/>
  <rect id="input" xy="#svgdx|H 10" wh="30 10" text="input.xml" rx="3" class="d-fill-cornflowerblue d-text-ol"/>
  <rect id="output" xy="#svgdx|h 10" wh="30 10" text="diagram.svg" rx="3" class="d-fill-green d-text-ol"/>

  <line start="#input" end="#svgdx" class="d-arrow"/>
  <line start="#svgdx" end="#output" class="d-arrow"/>
</svg>