Access HTTP response data saved in a variable with colon - google-workflows

Question

I'm using Google Cloud Workflow to call via http.get a CloudRun app that returns a XML document that has been converted to json, the below json gets successfully returned to Workflow in Step 2 which contains the converted XML to json in the body.
{
"body": {
"ResponseMessage": {
"#xmlns": "http://someurl.com/services",
"Response": {
"#xmlns:a": "http://someurl.com/data",
"#xmlns:i": "http://www.w3.org/2001/XMLSchema-instance",
"a:ReferenceNumber": {
"#i:nil": "true"
},
"a:DateTime": "2023-01-01T00:17:38+0000",
"a:TransactionId": "154200432",
"a:Environment": "Development",
"a:RequestDateTime": "2023-01-01T11:17:39",
}
},
"code": 200,
"headers": {
"Alt-Svc": "h3=\":443\"; ma=2592000,h3-29=\":443\"; ma=2592000,h3-Q050=\":443\"; ma=2592000,h3-Q046=\":443\"; ma=2592000,h3-Q043=\":443\"; ma=2592000,quic=\":443\"; ma=2592000; v=\"46,43\"",
"Content-Length": "1601",
"Content-Type": "application/json",
"Date": "Sun, 01 Jan 2023 00:17:39 GMT",
"Server": "Google Frontend",
"X-Cloud-Trace-Context": "931754ab82102397eb07775171485850"
}
}
}
The full yaml of the workflow is below and without step3/step4 it works. In step3 I try to access an element in the json which is returned from step2 as per https://cloud.google.com/workflows/docs/http-requests#access-data
main:
params: [args]
steps:
- step1:
assign:
- searchURL: ${"https://myfunction.a.run.app/search/" + args.type + "/" + args.serial}
- step2:
call: http.get
args:
url: ${searchURL}
result: s2result
- step3:
assign:
- resubmitURL: '${https://myfunction.a.run.app/resubmit/" + ${s2result.body.ResponseMessage.Response.a:TransactionId} }'
- step4:
call: http.get
args:
url: ${resubmitURL}
result: s4result
- returnOutput:
return: ${s4result}
However due to the colon : in the field I'm trying to access there are yaml parsing errors when I attempt to save another variable assignment. How can I access a HTTP response data saved in a variable when there are colons in the property field.
The errors in the console are similar too
Could not deploy workflow: main.yaml:14:25: parse error: in workflow 'main', step 'step3': token recognition error at: ':'
- resubmitURL: '${"https://myfunction.a.run.app/resubmit/" + ${s2result.body.ResponseMessage.Response.a:TransactionId}'
^
main.yaml:14:25: parse error: in workflow 'main', step 'step3': mismatched input '+' expecting {'[', LOGICAL_NOT, '(', '-', TRUE, FALSE, NULL, NUM_FLOAT, NUM_INT, STRING, IDENTIFIER}
- resubmitURL: '${"https://myfunction.a.run.app/resubmit/" + ${s2result.body.ResponseMessage.Response.a:TransactionId}'

Answer 1

Two techniques are required to reference map keys with special characters like this:
As recommended in the documentation, all expressions should be wrapped in single quotes to avoid YAML parsing errors (i.e. '${...}').
When referencing keys with special characters, you can use array notation to wrap the key name in quotes (i.e. var["KEY"]).
Together, it looks like this:
main:
steps:
- init:
assign:
- var:
key:
"co:lon": bar
- returnOutput:
return: '${"foo" + var.key["co:lon"]}'

Answer 2

In your code you are using an expression inside an expression:
- resubmitURL: '**${**"https://myfunction.a.run.app/resubmit/" + **${**s2result.body.ResponseMessage.Response.a:TransactionId**}**'
In this sample from your error message your not even closing the expressions right.
If you pack everything into one expression and use the hint from Kris with the key, it should deploy:
- resubmitURL: '${"https://myfunction.a.run.app/resubmit/" + s2result.body.ResponseMessage.Response["a:TransactionId"]}'
Here is my full test case:
main:
params: [args]
steps:
- init_assign:
assign:
- input: ${args}
- s2result:
body:
ResponseMessage:
Response:
"a:TransactionId": "Test"
- resubmitURL: '${"https://myfunction.a.run.app/resubmit/" + s2result.body.ResponseMessage.Response["a:TransactionId"]}'
- log1:
call: sys.log
args:
text: ${resubmitURL}
severity: INFO
With the log: 'https://myfunction.a.run.app/resubmit/Test'