[Bug] XPath filter returns no results

[brad-young]

Describe the bug
I am trying to chain together a few API calls. Step #1, get a TOKEN, Step #2, use the token in subsequent calls.

Here is the sample response from the TOKEN API call:

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope
  xmlns:soap="http://www.w3.org/2003/05/soap-envelope"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <soap:Body>
    <LoginResponse
      xmlns="http://url/DataService/">
      <LoginResult>xxx-777-xxx-123</LoginResult>
    </LoginResponse>
  </soap:Body>
</soap:Envelope>

Then in my "next" API call, I am using the Insomnia RESPONSE functionality, by grabbing the TOKEN from the body.

Using the following XPath filter:

//*[local-name(.)='LoginResult']/text()

However, the UI in the modal window says "Returned no results".

The example does work in https://extendsclass.com/xpath-tester.html

It appears to be the xmlns value

Screenshots
attached

Desktop (please complete the following information):

• OS: macOS 10.14.6
  
  

[gschier]

I think I've seen this reported before somewhere. It looks like the XPath library we're using doesn't like the xmlns="http://url/DataService/" attribute. Removing this makes the query //LoginResult work. However, the text() function also seems to be not supported, as //LoginResult/text() returns nothing.

Perhaps we should look at updating our XPath dependency or finding a more-complete one.

[brad-young]

yeah, the hard part is not being able to control the TOKEN API call that adds the xmlns. And .... I don't think there's another way to do this, correct? If I want to chain together commands and grab the token value, this is really the only method.

[gschier]

Not quite. You could write your own fork of the Response Tag plugin or maybe make use of this one https://insomnia.rest/plugins/insomnia-plugin-response-eval

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[HumanAftrAll]

I'm also facing this problem!

My XML response:

<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope
  xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
  xmlns="urn:enterprise.soap.sforce.com"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <soapenv:Body>
    <loginResponse>
      <result>
        <metadataServerUrl>invalidurl.com/metadata</metadataServerUrl>
        <passwordExpired>false</passwordExpired>
        <sandbox>false</sandbox>
        <serverUrl>https://invalidurl.com</serverUrl>
        <sessionId>COMPLETELYINVALIDVALUE</sessionId>
        <userId>redacted</userId>
        <userInfo>
          <accessibilityMode>false</accessibilityMode>
          <currencySymbol xsi:nil="true"/>
          <orgAttachmentFileSizeLimit>5242880</orgAttachmentFileSizeLimit>
          <orgDefaultCurrencyIsoCode xsi:nil="true"/>
          <orgDefaultCurrencyLocale xsi:nil="true"/>
          <orgDisallowHtmlAttachments>false</orgDisallowHtmlAttachments>
          <orgHasPersonAccounts>false</orgHasPersonAccounts>
          <organizationId>redacted</organizationId>
          <organizationMultiCurrency>true</organizationMultiCurrency>
          <organizationName>redacted</organizationName>
          <profileId>redacted</profileId>
          <roleId>redacted</roleId>
          <sessionSecondsValid>7200</sessionSecondsValid>
          <userDefaultCurrencyIsoCode>USD</userDefaultCurrencyIsoCode>
          <userEmail>redacted</userEmail>
          <userFullName>redacted</userFullName>
          <userId>redacted</userId>
          <userLanguage>redacted</userLanguage>
          <userLocale>redacted</userLocale>
          <userName>redacted</userName>
          <userTimeZone>redacted</userTimeZone>
          <userType>Standard</userType>
          <userUiSkin>Theme3</userUiSkin>
        </userInfo>
      </result>
    </loginResponse>
  </soapenv:Body>
</soapenv:Envelope>

And I want to get the value under <sessionId> with the following XPath: /soapenv:Envelope/soapenv:Body/loginResponse/result/sessionId. Adding the extra / at the start did not work...

The same XPath works when testing it elsewhere.

[ppazos]

When I try to filter by XPath on a reponse body, to use the value in another request, I always get "no results", and then if I erase the XPath, I get "Invalid XPath query: b64::::46b" which doesn't make sense since the field is empty!

This is on an insomnia just updated today!

[develohpanda]

There appears to be an issue with XPath if namespaces are used. For instance, if <foo><bar>baz</baz></foo> is used with the XPath of /foo/bar, then baz is returned as a result successfully, but if a namespace exists as per the example in #2050 (comment), then XPath fails to resolve it.

It appears that the XPath library we use requires the namespaces to be sent in code. 🤔 These seem to be the same findings as the previous comments where namespace attributes cause issues.

@ppazos, is the XPath query you are using by chance, operating on a response that contains namespaces? The error you found where a result is shown when the filter is empty is a valid edge case for sure - I have raised a PR to fix that: #4012.

[ppazos]

@develohpanda the xml I'm querying has ns declared in the root element:

<composition
  xmlns="http://schemas.openehr.org/v1"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="COMPOSITION" archetype_node_id="openEHR-EHR-COMPOSITION.test_all_datatypes.v1">

This uses the default ns http://schemas.openehr.org/v1, so the element names don't include any ns information. For instance if you have xmlns:xxx="http://schemas.openehr.org/v1", then all tags will be xxx:tag

This is the full XML:

<composition
  xmlns="http://schemas.openehr.org/v1"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="COMPOSITION" archetype_node_id="openEHR-EHR-COMPOSITION.test_all_datatypes.v1">
  <name xsi:type="DV_TEXT">
    <value>Test all datatypes</value>
  </name>
  <uid xsi:type="OBJECT_VERSION_ID">
    <value>c8a0a6ef-a006-497a-b674-c1e595c30303::CABOLABS_EHR_SERVER::1</value>
  </uid>
  <archetype_details>
    <archetype_id>
      <value>openEHR-EHR-COMPOSITION.test_all_datatypes.v1</value>
    </archetype_id>
    <template_id>
      <value>test_all_datatypes.en.v1</value>
    </template_id>
    <rm_version>1.0.2</rm_version>
  </archetype_details>
  <language>
    <terminology_id>
      <value>ISO_639-1</value>
    </terminology_id>
    <code_string>es</code_string>
  </language>
  <territory>
    <terminology_id>
      <value>ISO_3166-1</value>
    </terminology_id>
    <code_string>UY</code_string>
  </territory>
  <category>
    <value>event</value>
    <defining_code>
      <terminology_id>
        <value>openehr</value>
      </terminology_id>
      <code_string>433</code_string>
    </defining_code>
  </category>
  <composer xsi:type="PARTY_IDENTIFIED">
    <name>Dr. Pablo Pazos</name>
  </composer>
  <context>
    <start_time>
      <value>2021-09-03T21:06:07.424Z</value>
    </start_time>
    <setting>
      <value>Hospital Montevideo</value>
      <defining_code>
        <terminology_id>
          <value>openehr</value>
        </terminology_id>
        <code_string>229</code_string>
      </defining_code>
    </setting>
  </context>
  <content xsi:type="OBSERVATION" archetype_node_id="openEHR-EHR-OBSERVATION.test_all_datatypes.v1">
    <name xsi:type="DV_TEXT">
      <value>Blood Pressure</value>
    </name>
    <language>
      <terminology_id>
        <value>ISO_639-1</value>
      </terminology_id>
      <code_string>es</code_string>
    </language>
    <encoding>
      <terminology_id>
        <value>UNICODE</value>
      </terminology_id>
      <code_string>UTF-8</code_string>
    </encoding>
    <subject xsi:type="PARTY_IDENTIFIED">
      <external_ref>
        <id xsi:type="HIER_OBJECT_ID">
          <value>11111111-1111-1111-1111-111111111111</value>
        </id>
        <namespace>DEMOGRAPHIC</namespace>
        <type>PERSON</type>
      </external_ref>
    </subject>
    <data archetype_node_id="at0001">
      <name xsi:type="DV_TEXT">
        <value>history</value>
      </name>
      <origin>
        <value>2021-09-03T21:06:07.425Z</value>
      </origin>
      <events xsi:type="POINT_EVENT" archetype_node_id="at0002">
        <name xsi:type="DV_TEXT">
          <value>any event</value>
        </name>
        <time>
          <value>2021-09-03T21:06:07.425Z</value>
        </time>
        <data xsi:type="ITEM_TREE" archetype_node_id="at0003">
          <name xsi:type="DV_TEXT">
            <value>Arbol</value>
          </name>
          <items xsi:type="ELEMENT" archetype_node_id="at0011">
            <name xsi:type="DV_TEXT">
              <value>Count</value>
            </name>
            <value xsi:type="DV_COUNT">
              <magnitude>4</magnitude>
            </value>
          </items>
        </data>
      </events>
      <events xsi:type="POINT_EVENT" archetype_node_id="at0002">
        <name xsi:type="DV_TEXT">
          <value>any event</value>
        </name>
        <time>
          <value>2021-09-03T21:06:07.425Z</value>
        </time>
        <data xsi:type="ITEM_TREE" archetype_node_id="at0003">
          <name xsi:type="DV_TEXT">
            <value>Arbol</value>
          </name>
          <items xsi:type="ELEMENT" archetype_node_id="at0011">
            <name xsi:type="DV_TEXT">
              <value>Count</value>
            </name>
            <value xsi:type="DV_COUNT">
              <magnitude>5</magnitude>
            </value>
          </items>
        </data>
      </events>
      <events xsi:type="POINT_EVENT" archetype_node_id="at0002">
        <name xsi:type="DV_TEXT">
          <value>any event</value>
        </name>
        <time>
          <value>2021-09-03T21:06:07.425Z</value>
        </time>
        <data xsi:type="ITEM_TREE" archetype_node_id="at0003">
          <name xsi:type="DV_TEXT">
            <value>Arbol</value>
          </name>
          <items xsi:type="ELEMENT" archetype_node_id="at0011">
            <name xsi:type="DV_TEXT">
              <value>Count</value>
            </name>
            <value xsi:type="DV_COUNT">
              <magnitude>6</magnitude>
            </value>
          </items>
        </data>
      </events>
    </data>
  </content>
</composition>

And I'm trying to access this value: c8a0a6ef-a006-497a-b674-c1e595c30303::CABOLABS_EHR_SERVER::1

[develohpanda]

Thanks @ppazos, that'll be very helpful to debug, alongside the other examples in this issue.

Unfortunately I don't have any timeframe for when this might be fixed (right now), on looking through https://github.com/goto100/xpath there doesn't appear to be a straightforward solution using this, so we might need to explore other libraries. I am certainly available and happy to assist in case anybody wants to pick this up! 🙌🏽

[ppazos]

I'm ignorant about libraries for JS development specially for desktop apps. Though if there is a DOM implemented somewhere, it might have XPath https://developer.mozilla.org/en-US/docs/Web/XPath/Introduction_to_using_XPath_in_JavaScript

[rippo]

I ran into this issue but to help others, the XML API returns this. In my case I need to get the Guid, notice I have a ns inside of TicketHeader.

To get you can use the following xPath, HTH someone who hits this issue

//*[local-name(.)="Guid"]/text()

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope
	xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:xsd="http://www.w3.org/2001/XMLSchema">
	<soap:Header>
		<TicketHeader
			xmlns="http://www.webcrm.com/">
			<Guid>2f6931c2-f2f6-4780-99bd-XXXXXXX</Guid>
		</TicketHeader>
	</soap:Header>
	<soap:Body>
		<AuthenticateResponse
			xmlns="http://www.webcrm.com/">
			<AuthenticateResult>
				<Message />
				<Code>0</Code>
			</AuthenticateResult>
		</AuthenticateResponse>
	</soap:Body>
</soap:Envelope>

[myst3k]

Ran into this issue and spent many more hours than I would have liked to try to authenticate with Tableau on further requests. Following @rippo example.

/*[name()='tsResponse']/*[name()='credentials']/@token

<tsResponse
	xmlns="http://tableau.com/api"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://tableau.com/api https://help.tableau.com/samples/en-us/rest_api/ts-api_3_16.xsd">
	<credentials token="mySecretToken" estimatedTimeToExpiration="364:23:49">
		<site id="1234" contentUrl="myAppName"/>
		<user id="5678"/>
	</credentials>
</tsResponse>