Using jsonPath looking for a string - jsonpath

Question

I'm trying to use jsonPath and the pick function to determine if a rule needs to run or not based on the current domain. A simplified version of what I'm doing is here:
global
{
dataset shopscotchMerchants <- "https://s3.amazonaws.com/app-files/dev/merchantJson.json" cachable for 2 seconds
}
rule checkdataset is active
{
select when pageview ".*" setting ()
pre
{
merchantData = shopscotchMerchants.pick("$.merchants[?(#.merchant=='Telefora')]");
}
emit
<|
console.log(merchantData);
|>
}
The console output I expect is the telefora object, instead I get all three objects from the json file.
If instead of merchant=='Telefora' I use merchantID==16 then it works great. I thought jsonPath could do matches to strings as well. Although the example above isn't searching against the merchantDomain part of the json, I'm experiencing the same problem with that.

Answer 1

Your problem comes from the fact that, as stated in the documentation, the string equality operators are eq, neq, and like. == is only for numbers. In your case, you want to test if one string is equal to another string, which is the job of the eq string equality operator.
Simply swap == for eq in you JSONpath filter expression and you will be good to go:
global
{
dataset shopscotchMerchants <- "https://s3.amazonaws.com/app-files/dev/merchantJson.json" cachable for 2 seconds
}
rule checkdataset is active
{
select when pageview ".*" setting ()
pre
{
merchantData = shopscotchMerchants.pick("$.merchants[?(#.merchant eq 'Telefora')]"); // replace == with eq
}
emit
<|
console.log(merchantData);
|>
}
I put this to the test in my own test ruleset, the source for which is below:
ruleset a369x175 {
meta {
name "test-json-filtering"
description <<
>>
author "AKO"
logging on
}
dispatch {
domain "exampley.com"
}
global {
dataset merchant_dataset <- "https://s3.amazonaws.com/app-files/dev/merchantJson.json" cachable for 2 seconds
}
rule filter_some_delicous_json {
select when pageview "exampley.com"
pre {
merchant_data = merchant_dataset.pick("$.merchants[?(#.merchant eq 'Telefora')]");
}
{
emit <|
try { console.log(merchant_data); } catch(e) { }
|>;
}
}
}