Replace special characters in JSON response

Question

Hi guys, 
 
 We have an issue where an API push is failing because we are receiving JSON data and then pushing this data straight back out to the API. The API can output special characters but won't accept them. To get around this, we need to find a way to replace certain special characters from value fields with encoded characters. Example: 
 
 Received JSON: 
 
 {test1: "this is a test with some valid characters", 
 test2: "this is a test with some invalid characters , ! &pound;"} 
 
 Pushed JSON: 
 
 {test1: "this is a test with some valid characters", 
 test2: "this is a test with some invalid characters .co .ex .po"} 
 
 So in this instance the aim would be to replace those special characters at the end of test2. 
 
 Is there a way to do this, potentially with REGEX or a replace string? It would need to check all the value fields and replace any of the special characters in there with some encoding we've defined. 
 
 Thanks for any help.

Peter Lewis · Accepted Answer

Hmmm, do you know the structure of the response and know which fields you want to index? If you do, you can use a!fromJson() to convert your JSON to an Appian dictionary. Then, you could use the index() function to return certain fields that you can then run the cleanwith() or stripwith() on. Then, do the reverse - convert back to JSON and send out the response. 
 You might have to weigh this against regex too. At some point, it may be easier to just use regex rather than all these manipulations in Appian. To use regex, you have to install a plugin: https://community.appian.com/b/appmarket/posts/regular-expression-functions 
 Unfortunately, I'm not much of a regex coder so I'm not sure what syntax would be best, but someone else on here might be able to help you with that syntax

Peter Lewis · Answer

REGEX would probably work, but you could also use out-of-the-box Appian functions. 
 The stripwith() function will remove any characters you define as invalid. So if you wanted to specifically remove the &pound; symbol, you could use stripwith() like this: 
 stripwith(
 [JSON Here],
 "&#163;"
) 
 You can also use the cleanwith() function which does the reverse: it only keeps the characters you define as valid and removes all others. So for example, if you only want to allow letters and numbers, you could use cleanwith() like this: 
 cleanwith(
 [JSON Here],
 "abcdefghijklmnopqrstuvwxyz0123456789"
) 
 Both of the methods described above remove the problem characters. If you want to replace them with something else, you can also try the replace function .

ravalik · Answer

HI johng, 
 Apply clean() function to the incoming text either before you save or before you display . Regex() function resolves your issue atmost. As you want to replace the special characters with some other encoding, try using substitute() function. 
 Thanks, 
 ravalik

Replace special characters in JSON response

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