Allegro.pl - convert prices to EUR

1/15/2022, 4:16:32 PM - Convert prices to EUR. You have to get a free API key from https://free.currencyconverterapi.com/ in order to use this script. The first time you use it on allegro, you will receive a prompt for the API key. It will keep prompting until you provide a valid key. If you don't want to see the prompt, turn off the script.

目前為 2022-01-15 提交的版本,檢視 最新版本

// ==UserScript==
// @name        Allegro.pl - convert prices to EUR
// @namespace   Violentmonkey Scripts
// @match       https://allegro.pl/oferta/*
// @match       https://allegro.pl/uzytkownik/*
// @match       https://allegro.pl/listing
// @run-at      document-idle
// @grant       none
// @version     1.2
// @author      -
// @description 1/15/2022, 4:16:32 PM - Convert prices to EUR. You have to get a free API key from https://free.currencyconverterapi.com/ in order to use this script. The first time you use it on allegro, you will receive a prompt for the API key. It will keep prompting until you provide a valid key. If you don't want to see the prompt, turn off the script.
// ==/UserScript==


function pricePlnToEur(conversionRate, match1, match2) {
  const priceStr = "".concat(match1.replace(/\ /g, ''), match2)
    const priceGrosze = parseInt(priceStr) // price expressed as an integer amount of Grosz
    
    console.log(priceGrosze)
    const priceCents = Math.round(priceGrosze * conversionRate) // price expressed as an integer amount of Cents. Round to nearest (i.e. 16.5 -> 17)
    console.log(priceCents)
    const priceCentsStr = priceCents.toString() // string version of price expressed as an integer amount of Cents
    const priceEurStr = priceCentsStr.slice(0, -2) // whole Euros
    const priceCentsFracStr = priceCentsStr.slice(-2) // Cents after decimal point
    const priceEurStrFull = "".concat(priceEurStr.padStart(1, "0"), ".", priceCentsFracStr.padStart(2, "0")) // price in Euro expressed as string. the padding is to prevent prices like 1 cent or 44 cents from showing up with necessary leading zeros.
    return priceEurStrFull
}

function getElementsByXPath(xpath, parent)
{
    let results = [];
    let query = document.evaluate(xpath, parent || document,
        null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    for (let i = 0, length = query.snapshotLength; i < length; ++i) {
        results.push(query.snapshotItem(i));
    }
    return results;
}

async function main() {
  
// We can only await inside an async function, so the whole script has to be an async function.
// I'm not indenting this function because it is the whole file.

storage = window.localStorage
//console.log("mystorage", storage)
const messageTitle = "Allegro convert to EUR greasemonkey script: "
const forexApiBase = "https://free.currconv.com/api/v7/convert"
const forexApi = "".concat(forexApiBase, "?q=PLN_EUR&compact=ultra&apiKey=")

// If the foreign exchange api key is not present, request it from the user, and save it in storage.
if(storage.getItem("forexApiKey") === null) {
  const newForexApiKey = prompt("".concat(messageTitle, "Please enter API Key. You can request it for free from https://free.currencyconverterapi.com/"), "")
  const apiCallValidate = "".concat(forexApi, newForexApiKey)
  console.log("".concat(messageTitle, "about to create the following request to validate the API key: ", apiCallValidate))
  
  // validate the key
  fetch(apiCallValidate).then(function(response) {
    console.log(response)
    if (response.status !== 200) {
      // Apparently errors >= 400 do not count to trigger onerror
      throw new Error("Response HTTP code not 200 during api key validation") // fixme: use a typed error
    }
    storage.setItem("forexApiKey", newForexApiKey)
  }).catch(function(error) {
    alert("".concat(messageTitle, "Error performing API request. Is the key correct?"))
    console.log("".concat(messageTitle, "Error performing API request. Is the key correct?"))
    console.log(messageTitle, error)
  })
}

// get the api key from storage and convert the prices.
const forexApiKey = storage.getItem("forexApiKey")
if(forexApiKey !== null) {
  // perform actual call with the api key
  apiCall = "".concat(forexApi, forexApiKey)
  console.log("".concat(messageTitle, "about to create the following request to get the conversion rate: ", apiCall))
  
  fetch(apiCall).then(function(response) {
    if (response.status !== 200) {
      // Apparently errors >= 400 do not count to trigger onerror
      throw new Error("Response HTTP code not 200 during API call") // fixme: use a typed error
    }
    return response.json()
  }).then(function(data) {
    // convert stuff
    console.log("".concat(messageTitle, "found conversion rate: ", data["PLN_EUR"]))
    // find the price:
    
    // which page are we on?
    const loc = window.location.toString()
    
    // item page
    if(loc.startsWith("https://allegro.pl/oferta/")) {
    
      // convert item price
      const list = document.querySelectorAll('[aria-label^="cena "]') // ^= means "begins with".
      console.log("".concat(messageTitle, "detected item page."))
      console.log("".concat(messageTitle, "found the following elements: "))
      console.log(list)
      if (list.length !== 1) {
        const elmErr = "".concat(messageTitle, "Found too many or no elements when searching for price. Aborting.")
        console.log(elmErr)
        throw new Error(elmErr) // fixme: use a typed error
      }
      const priceDiv = list[0]
      const priceLabel = priceDiv.attributes["aria-label"].value
      const matches = priceLabel.match(/^cena ([0-9]{1,3}(?:\ [0-9]{3})*)\.([0-9]{2}) zł$/) // note the decimal point is a comma on the listing page and a period on the item page. The regex means that you have 1-3 digits, then maybe (a space and 3 digits) repeated.
      priceEurStrFull = pricePlnToEur(data["PLN_EUR"], matches[1], matches[2])
      const priceEurSpan = document.createElement('span')
      priceEurSpan.textContent = "".concat("\u00a0=\u00a0", priceEurStrFull, "\u00a0EUR")
      console.log("priceDiv:")
      console.log(priceDiv)
      priceDiv.appendChild(priceEurSpan) // add span that contains euro price
      
      // convert prices of carousel items
      function attachEurCarousel() {
        carouselSpans = getElementsByXPath("//div[contains(@class, 'carousel-item')]/div/ul/li/span/span[contains(text(),' zł')]/..")
        
        console.log("carouselSpans: ")
        console.log(carouselSpans)
        carouselSpans.forEach(function(priceSpan) {
          console.log(priceSpan)
          if (!priceSpan.classList.contains("priceEur")) { // priceEur would mean it's already an Euro price we placed
            const matches =  priceSpan.innerText.match(/^([0-9]{1,3}(?:\ [0-9]{3})*),([0-9]{2}) zł$/) // note the decimal point is a comma
            priceEurStrFull = pricePlnToEur(data["PLN_EUR"], matches[1], matches[2])
            const priceEurSpan = document.createElement('span')
            priceSpan.classList.forEach(function(cls) {
              priceEurSpan.classList.add(cls)
            })
            priceEurSpan.classList.add("priceEur") // used to check if this span has already been added
            priceEurSpan.textContent = "".concat(priceEurStrFull, "\u00a0EUR")
            priceSpan.parentNode.replaceChild(priceEurSpan, priceSpan) // we don't leave the original price in since there's no space left.
          }
        })
      }
      
      attachEurCarousel()
      
      document.addEventListener('scroll', attachEurCarousel)
    
    // listing page
    } else if (loc.startsWith("https://allegro.pl/uzytkownik/") || loc.startsWith("https://allegro.pl/listing")) {
      console.log("".concat(messageTitle, "detected listing page."))
      
      function attachEurListing() {
        list = document.querySelectorAll('[aria-label$=" zł aktualna cena"]') // $= means "ends with".
        console.log("".concat(messageTitle, "found the following elements: "))
        console.log(list)
        
        list.forEach(function(priceSpan) {  
          const priceLabel = priceSpan.attributes["aria-label"].value
          const matches = priceLabel.match(/^([0-9]{1,3}(?:\ [0-9]{3})*),([0-9]{2}) zł aktualna cena$/) // note the decimal point is a comma on the listing page and a period on the item page. The regex means that you have 1-3 digits, then maybe (a space and 3 digits) repeated.
          priceEurStrFull = pricePlnToEur(data["PLN_EUR"], matches[1], matches[2])
          const priceEurSpan = document.createElement('span')
          priceEurSpan.textContent = "".concat("\u00a0=\u00a0", priceEurStrFull, "\u00a0EUR")
          priceSpan.classList.forEach(function(cls) {
            priceEurSpan.classList.add(cls)
          })
          priceEurSpan.classList.add("priceEur") // used to check if this span has already been added
          priceDiv = priceSpan.parentNode
          siblings = priceDiv.childNodes

          // check if the span has already been added to prevent adding it multiple times
          var alreadyAttached = false
          siblings.forEach(function (sibling) {
            if (sibling.classList.contains("priceEur")) {
              alreadyAttached = true
            }
          })
          if (!alreadyAttached) {
            priceDiv.appendChild(priceEurSpan) // add span that contains euro price
          }
        })
      }
      
      attachEurListing()
      
      document.addEventListener('scroll', attachEurListing) // needed because when you run the callback items that are off screen will not be processed
      
      const observer = new MutationObserver(attachEurListing) // eg used for going to the next results page
      observer.observe(document, { attributes: true, childList: true, subtree: true })
      
    }
  }).catch(function(error) {
    // fixme: make this better
    console.log("".concat(messageTitle, "Error performing API request. Is the key correct?"))
    console.log(messageTitle, error)
  })
}
}

var runMainOnce = (function() {
  var executed = false
  return function() {
    if (!executed) {
      executed = true
      main()
    }
  }
})()



// Execute the code in one of two ways...

// This event runs when we switch into a tab that just loaded.
document.addEventListener('visibilitychange', function(event) {
  if (document.visibilityState === "visible") {
    runMainOnce()
  }
})

// This code runs if the tab is visible while it's loading.
if (document.visibilityState === "visible") {
  runMainOnce()
}