astro/dist/runtime/server/render/slot.js

Astro is a modern site builder with web best practices, performance, and DX front-of-mind.

import { renderTemplate } from "./astro/render-template.js";
import { HTMLString, markHTMLString, unescapeHTML } from "../escape.js";
import { renderChild } from "./any.js";
import { chunkToString } from "./common.js";
const slotString = Symbol.for("astro:slot-string");
class SlotString extends HTMLString {
  instructions;
  [slotString];
  constructor(content, instructions) {
    super(content);
    this.instructions = instructions;
    this[slotString] = true;
  }
}
function isSlotString(str) {
  return !!str[slotString];
}
function renderSlot(result, slotted, fallback) {
  if (!slotted && fallback) {
    return renderSlot(result, fallback);
  }
  return {
    async render(destination) {
      await renderChild(destination, typeof slotted === "function" ? slotted(result) : slotted);
    }
  };
}
async function renderSlotToString(result, slotted, fallback) {
  let content = "";
  let instructions = null;
  const temporaryDestination = {
    write(chunk) {
      if (chunk instanceof SlotString) {
        content += chunk;
        if (chunk.instructions) {
          instructions ??= [];
          instructions.push(...chunk.instructions);
        }
      } else if (chunk instanceof Response) return;
      else if (typeof chunk === "object" && "type" in chunk && typeof chunk.type === "string") {
        if (instructions === null) {
          instructions = [];
        }
        instructions.push(chunk);
      } else {
        content += chunkToString(result, chunk);
      }
    }
  };
  const renderInstance = renderSlot(result, slotted, fallback);
  await renderInstance.render(temporaryDestination);
  return markHTMLString(new SlotString(content, instructions));
}
async function renderSlots(result, slots = {}) {
  let slotInstructions = null;
  let children = {};
  if (slots) {
    await Promise.all(
      Object.entries(slots).map(
        ([key, value]) => renderSlotToString(result, value).then((output) => {
          if (output.instructions) {
            if (slotInstructions === null) {
              slotInstructions = [];
            }
            slotInstructions.push(...output.instructions);
          }
          children[key] = output;
        })
      )
    );
  }
  return { slotInstructions, children };
}
function createSlotValueFromString(content) {
  return function() {
    return renderTemplate`${unescapeHTML(content)}`;
  };
}
export {
  SlotString,
  createSlotValueFromString,
  isSlotString,
  renderSlot,
  renderSlotToString,
  renderSlots
};