I am trying to display Twitter feeds as a list of titles/hyperlinks. Previously,

Hi Wendy.. I have done this.. Use the OAuth Smart Services to call the Twitter REST API.. then use the JSON to XML function and parse the response as XML instead of JSON.. Here is an example you might use to extract all the posts from an array of twitter posts

xpathsnippet(jsontoxml(ac!ResponseBody), "/json/e/text/text()")

Thanks Malcolm! I was able to get this working exactly as you said, now the only issue is that I am getting an error with the xpath expression if I try to pull back too much data. Everything works fine for approx 10 tweets, but more than that causes an error. (xpathsnippet(jsontoxml(pv!ResponseBody), "/json/e/text/text()") (Expression evaluation error at function 'xpathsnippet': Error evaluating function 'xpathsnippet' : An error occurred while trying to parse the XML stream.) ) Have you ever seen this before? Thanks for your help!

My system does not experience that issue.. What version of Appian are you using? You might be hitting some data cap thresholds that were present in earlier versions.. Or you might need to adjust data caps in your custom.properties file.. You can also toggle the amount of twitter posts you receive at once via the Twitter API so that you don't retrieve large data sets.

Malcolm,
Looks like the execution is failing at xpathsnippet function call. I could see the json data parsed successfully in XML format and the xpathsnippet function is failing when we search for text or id list. Strangely jboss is also not throwing any error. if data cap is an issue the xml conversion function shouldn't work? any ways I could confirm that no truncation has happened after parsing the json to xml. Most likely data cap property applies only for user entered text I believe not when the system activity nodes updating them. Perhaps there are some limitations on xpathsnippet function. Do you know if there are any known limitations?

I have not seen any issue or aware of any issue with data caps and xpathsnippet.. I would suggest performing the jsontoxml function and validating the result in an XML validator to ensure it is not malformed.. also, be sure to note your version of Appian you are using.

www.w3schools.com/.../xml_validator.asp

Thanks Malcolm. I have validated the response xml and it says no error found. We are using appian 6.7.1. My JSON data is having 59000 characters and xml representation is around 66850 in length.my actual data cap setting is at 10000 which means it did not failed to convert json to xml though the data is well above the limits. We tried everything possible and most likely will end up writing a custom function to extract the data from JSON representation directly to an array. I could see a plugin already in shared components and some reason it is not working as expected with json array representation.

I just tested on my Appian Cloud 7.2 environment.. Retrieved the last 100 tweets from the Appian twitter account.. JSON response was 138709 characters.. XML conversion was 179401 characters.. everything worked perfectly.. parsed out the XML using xpathsnippet to retrieve the 100 tweets and twitter IDs into two text arrays using these functions - xpathsnippet(jsontoxml(ac!ResponseBody), "/json/e/text/text()") and xpathsnippet(jsontoxml(ac!ResponseBody), "/json/e/id/text()")

If you continue to experience this issue, I would suggest opening up a support ticket to help resolve. The primary difference between our environments is the version of Appian.

For your custom function idea.. I would suggest just downloading and enhancing the source code of the existing JSON functions.. These were developed and shared by an Appian partner.. my suspicion of why those JSON parsing functions are not working is that they might not be able the handle nested array structures inside a JSON string.

Thanks Malcolm for your inputs. We are experiencing this issues and I will ask our admin to raise a support ticket. and Yes, I am downloading the plugin and enhancing the source code (adding a new function thought) to handle the json array representation. Fortunately the developer has included source code in the jar file. I will let you know how it goes

the custom function to read the json response which is in the array form did worked for us. At this point this function is not in the good shape which can be shared with broader community as we have to implement something quick and dirty for some urgent needs. Thanks for your prompt response