How can I handle exceptions from an external source, eg a 404?

Question

So my goal is, using Google Appscripts, to call an external API for addresses, which returns a JSON/array with that information. 90% of the time, the API is fine. However, sometimes, I can legitimately call an address that is not in the API database, so the API gives me a 404 in this case.

My problem: When the API returns a 404, it ends the Appscript program that I am writing. How do I check the API response so that I can see if it is returning a 404 before I attempt to access it, which shuts the program down prematurely?

What I would like to do is to have the code: 1) understand an error has happened but still continue the program, 2) by creating an empty array in lieu of the property address data I am searching for. I know how to do 2), but I can't do 1 - I can't trigger the creation of that array based on the knowledge that a 404 call happened. Please help!

Thank you so much in advance!!

I have no idea what to try - I'm not sure I understand the handling exceptions portion of Appscript, because this is calling an external database and not an internal Google database, then returning a 404, so I don't know what applies and what does not.

Answer 1

Assuming that you call the API with UrlFetchApp, there are two ways to deal with it:

1. Disable exceptions on unsuccessful requests by setting muteHttpExceptions:

   const options = {
     'method': 'get',
     'muteHttpExceptions': true
     // Include other necessary options like headers
   };
   
   const response = UrlFetchApp.fetch(apiUrl, options);
   const responseCode = response.getResponseCode();
   
   if (responseCode === 200) {
     // Success, process the data
   } else if (responseCode === 404) {
     // Handle 404 error
     console.log("API returned 404: Address not found");
   } else {
     // Handle other types of errors
     console.log("Error with response code: " + responseCode);
   }
   

2. Wrap UrlFetchApp in try/catch block:

   try {
     const response = UrlFetchApp.fetch(apiUrl);
     const data = JSON.parse(response.getContentText());
   
     // Process your data
     // ...
   
   } catch (e) {
     // Check if the error is a 404
     if (e.message.includes("404")) {
       console.log("API returned 404: Address not found");
       // Handle 404 specific logic
     } else {
       // Handle other types of errors
       console.log("Error: " + e.message);
     }
   }