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Javascript

javascript expressions use to the otto Javascript VM

display-with-javascript.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: currency-converter-display-js
spec:
  http:
    - name: USD
      url: https://api.frankfurter.app/latest?from=USD&to=GBP,EUR,ILS
      display:
        javascript: |
          currencyCodes = { "EUR": "€", "GBP": "£", "ILS": "₪"}

          display = []
          for (var currency in json.rates) {
            display.push(currency + " = " + currencyCodes[currency] + json.rates[currency])
          }

          // final output to display
          "$1 = " + display.join(", ")
Troubleshooting

You can print to the console for rapid development e.g. console.log(JSON.stringify(json)), this is only shown in the logs

Underscore​

The underscore library is automatically imported so you can do the following:

display-format-with-underscore.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: http-check
spec:
  http:
    - name: USD
      url: https://api.frankfurter.app/latest?from=USD&to=GBP,EUR,ILS
      display:
        javascript: |
          currencyCodes = { "EUR": "€", "GBP": "£", "ILS": "₪"}
          "$1 = " + _.map(json.rates, function(rate, currency) {
               return currencyCodes[currency] + rate;
          }).join(", ");