XPATH returns null

[RTW]

Hi all. I'm trying to automate some tasks with Tableau. Basically the flow is:

1. Logon request to Tableau Server via HTTPS
2. Extract token
3. Pass tokens into other HTTPS requests
4. ???
5. Profit

I got pretty much everything worked out and working but I really don't like how I get the token out. Currently I'm using a convoluted mix of Search() and Substring() to extract it. I would love to use XPATH as its a lot easier to implement and I'm always game to learn new things.

Here is the XML data that is returned by the logon request:

<?xml version='1.0' encoding='UTF-8'?>
<tsResponse xmlns="http://tableau.com/api" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://tableau.com/api http://tableau.com/api/ts-api-3.6.xsd">
    <credentials token="THIS IS TOKEN">
        <site id="THIS IS SITE" contentUrl=""/>
        <user id="THIS IS USERID"/>
    </credentials>
</tsResponse>

From this I would like to extract the following string "THIS IS TOKEN" using XPATH. I used this tool to test the XPATH expression and this seems to work "string(/tsResponse/credentials/@token)"

The issue is running it into flow. Initially I was using the HTTP request action but I didn't want to make too many requests so I created a mockup where I paste a sample payload into a Compose action and have a second compose action that executes the XPATH.

This is the expression I use on the second Compose action where "Compose 2" has the text"

xpath(xml(outputs('Compose_2')),'string(/tsResponse/credentials/@token)')

Here is the result of the flow.

I've tired a few other XPATH examples from online and they seem to work but I just can't get this to function correctly. Any idea what I am doing wrong?

[abm · Accepted solution]

Try the following:

xpath(xml(outputs('Compose_2')),'//*[local-name()="credentials"]/@token')

[v-bacao-msft]

Hi @RTW ,

Please try to refer to the following method to configure Flow:

xPath-parsing-noob

XML-convert-to-other-XML-format

In addition, you can follow the link and get more details about the XPath() function:

https://docs.microsoft.com/en-gb/azure/logic-apps/workflow-definition-language-functions-reference#x...

Best Regards,

[RTW]

@abm Thank you, this worked.

I had to modify it slightly to xpath(xml(outputs('Compose_2')),'string(//*[local-name()="credentials"]/@token)') to get the correct output.

So, that being said, what did I do wrong?

[abm]

Hi @RTW 

XPath queries are not the straight forward ones. Glad to hear that it is working.

Thanks