How to print the Pattern used to extract Variable

[sp_9932]

Hello ,

I have a requirement to reserve the Pattern that will be used to extract a feild using Extract variable policy. For example , I want to get the Pattern out printed ( in my case

/user/details-list/{ID}/checkout ) so that i can use in the later step in the flow. I can get any of the

proxy.pathsuffix as below so need to extract some values out of it . When used , i only see

urirequest.ID or urirequest.CID etc

What should i do to get the Pattern aswell that is used to extract some feild out ? I want to preserve the pattern path for later use to replace some feilds from the next steps output in the flow.

<ExtractVariables name="ExtractVariables-1">
  <DisplayName>Extract a portion of the url path</DisplayName>
  <Source>request</Source>
  <URIPath>
    <Pattern ignoreCase="true">/user/details-list/{ID}/checkout</Pattern>
  </URIPath>
  <URIPath>
    <Pattern ignoreCase="true">/user/details-list/{ID}/balance</Pattern>
  </URIPath>
  <URIPath>
    <Pattern ignoreCase="true">/user/details-list/{CID}/checkout/stop-calculation/{SigID}</Pattern>
  </URIPath>
  <URIPath>
    <Pattern ignoreCase="true">/user/{COID}/profile</Pattern>
  </URIPath>
  <VariablePrefix>urirequest</VariablePrefix>
  <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
</ExtractVariables>

[sillan_dt]

Can you explain more with an example?

[Denis_KALITVI]

I think he wants to print the actual regex of the pattern: /user/details-list/{ID}/checkout

[sp_9932]

That’s correct, I want to get the expression used to extract variable itself. I have multiple URI paths that proxy gets called with. And to reconstruct the target URL , I am ending up in using many Assign messages with conditional checks both at Extract variable and also at Assign Message policy in the default Proxy endpoint . There should be some better way to handle is what I am thinking.

[sillan_dt]

For this you may need to use to multiple extract variable policies in each having a different pattern. I would use javascript policy instead to get the pattern matching with condition settings.

[sp_9932]

Hi Sillan: looks like the conditional statements won’t work with in Java Script. My initial thought was Java script - what would be the code you think will look with in Java script ? Path suffix MatchLike won’t work in JavaScript . Can you please guide.

[sillan_dt]

Inside javascript you can use pathsuffix as a variable and match the pattern using javascript string operations.

Ref: https://stackoverflow.com/questions/26246601/wildcard-string-comparison-in-javascript

https://trans4mind.com/personal_development/JavaScript/Regular%20Expressions%20Simple%20Usage.htm

[kurtkanaskie]

You can use multiple patterns and apply the Extract Variables policy in multiple locations.

For example

<URIPath>
    <Pattern ignoreCase="true">/user/details-list/{CID}</Pattern>
    <Pattern ignoreCase="true">/user/details-list/{CID}/checkout/stop-calculation/{SigID}</Pattern>
</URIPath>

 Then your could apply that same policy in each of the respective flows.

Maybe that's not what your trying to do, but perhaps it may help.

[dchiesa1]

You can't do just what you're describing with the ExtractVariables policy, though I thnk what you're asking for is a nifty idea for a small enhancement. 

If you really need the original pattern I would use JavaScript and just iterate through the patterns.  Maybe something like this: 

var patterns = {
        checkout: '/user/details-list/{ID}/checkout',
        balance: '/user/details-list/{ID}/balance',
        stop: '/user/details-list/{CID}/checkout/stop-calculation/{SigID}',
        profile: '/user/{COID}/profile'
      };

var re1 = new RegExp('\{([^}]+)\}', 'g');

function match(path) {
  return Object.keys(patterns)
    .map(function(key) {
      var pattern = patterns[key];
      var extractedNames = [];
      var m1;
      while ((m1 = re1.exec(pattern)) != null) {
        extractedNames.push(m1[1]);
      }
      var re = new RegExp('^' + pattern.replace(re1, '([^/]+)') + '$');
      var m = re.exec(path);
      if (m) {
        var obj = { patternName:key, pattern:pattern, extracts:{} };
        extractedNames.forEach(function(name, ix){
          obj.extracts[name] = m[1 + ix];
        });
        return obj;
      }
    })
    .find(function(value) { return value; });
}

var m = match(context.getVariable('proxy.pathsuffix'));
if (m) {
 // eg
 // { "patternName":"stop",
 //   "pattern":"/user/details-list/{CID}/checkout/stop-calculation/{SigID}",
 //   "names":{"CID":"567","SigID":"abcchdk"}
 // }
 context.setVariable('patternName', m.patternName);
 context.setVariable('pattern', m.pattern);
 Object.keys(m.names).forEach(function(fieldName) {
    context.setVariable('extracted.' + fieldName, m.names[fieldName]); 
 });
}