☰

BrickLink Price Averages

Adds the currently-for-sale price average to BL store listings

  1. // ==UserScript==
  2. // @name        BrickLink Price Averages
  3. // @name:en     BrickLink Price Averages
  4. // @namespace   Violentmonkey Scripts
  5. // @match       https://store.bricklink.com/*
  6. // @grant       none
  7. // @version     1.0
  8. // @author      The0x539
  9. // @description Adds the currently-for-sale price average to BL store listings
  10. // @run-at      document-body
  11. // @license     AGPL-3.0
  12. // ==/UserScript==
  13.  
  14. const RealXMLHttpRequest = window.XMLHttpRequest;
  15. class PatchedXMLHttpRequest extends RealXMLHttpRequest {
  16. 	constructor(...args) {
  17. 		super(...args);
  18. 		this.isSearch = false;
  19. 		this.jobDone = false;
  20. 	}
  21.  
  22. 	open(...args) {
  23. 		if (args[1].startsWith('/ajax/clone/store/searchitems.ajax')) {
  24. 			this.isSearch = true;
  25. 		}
  26. 		return super.open(...args);
  27. 	}
  28.  
  29. 	get responseText() {
  30. 		if (this.isSearch && !this.jobDone) {
  31. 			const response = JSON.parse(super.responseText);
  32. 			processSearchResponse(response);
  33. 			this.jobDone = true;
  34. 		}
  35.  
  36. 		return super.responseText;
  37. 	}
  38. }
  39. window.XMLHttpRequest = PatchedXMLHttpRequest;
  40.  
  41. const promises = new Map();
  42.  
  43. function processSearchResponse(response) {
  44. 	for (const item of response.result.groups.flatMap(g => g.items)) {
  45. 		const { itemID, colorID, itemName, colorName } = item;
  46. 		const key = (colorName + '\xA0' + itemName).trimStart();
  47. 		if (!promises.has(key)) {
  48. 			promises.set(key, getPrices(itemID, colorID));
  49. 		}
  50. 	}
  51. }
  52.  
  53. async function getPrices(itemID, colorID) {
  54. 	const response = await fetch(`/v2/catalog/catalogitem_pgtab.page?idItem=${itemID}&idColor=${colorID}`);
  55. 	const html = await response.text();
  56. 	const doc = new DOMParser().parseFromString(html, 'text/html');
  57.  
  58. 	const rows = doc.querySelectorAll('table.pcipgSummaryTable tr');
  59. 	const averages = [...rows]
  60. 		.filter(row => row.firstElementChild.innerText === 'Avg Price:')
  61. 		.map(row => row.lastElementChild.innerText);
  62.  
  63. 	const [new6Months, used6Months, newForSale, usedForSale] = averages;
  64. 	return { new6Months, used6Months, newForSale, usedForSale };
  65. }
  66.  
  67. function onUpdatePage(records, observer) {
  68. 	const selector = '.store-items article.table-row:not(:has(.buy div.average))';
  69.  
  70. 	const rows = records
  71. 		.flatMap(r => [...r.addedNodes])
  72. 		.filter(n => n instanceof HTMLElement)
  73. 		.flatMap(n => [...n.querySelectorAll(selector)]);
  74.  
  75. 	for (const row of rows) {
  76. 		addAverage(row);
  77. 	}
  78. }
  79.  
  80. async function addAverage(listing) {
  81. 	const key = listing.querySelector('.description p').innerText;
  82. 	const prices = await promises.get(key);
  83.  
  84. 	const condition = listing.querySelector('.condition strong').innerText;
  85. 	const price = (condition === 'Used') ? prices.usedForSale : prices.newForSale;
  86.  
  87. 	const newHtml = `
  88. 		<div class="average">
  89. 			<span>Average: </span>
  90. 			<strong>${price}</strong>
  91. 		</div>
  92. 	`;
  93. 	listing.querySelector('.buy').children[1].insertAdjacentHTML('afterend', newHtml);
  94. }
  95.  
  96. const observeOptions = { childList: true, subtree: true };
  97. new MutationObserver(onUpdatePage).observe(document.body, observeOptions);