Adding Customer Code blocks in the Pre- and Post- functions

[smiller0924]

I am just becoming familiar with your product. The majority of my experience is with Postman.

One of the features that I enjoy with Postman is to run custom programming either prior to or after a API call.

Here are examples of Pre-Request Scripts. The requirement is that I need to get a date to feed into a variable in a specific format:

var moment = require('moment'); pm.environment.set('PickupDate', moment().format("YYYY-MM-DD")+"T16:00:00Z");

This will get the date and then return the value in the format: 2022-12-30T16:00:00Z (Thes function is used to set a pickup request that must be in a specific format required by the carrier.

Another example would be:

var moment = require('moment') pm.environment.set("future_timestamp", moment().add(1, 'day').format("YYYY-MM-DD")+"T11:00:00Z")

This request is similar to the first. But it advanced the date by one day and returns the request as 2022-12-31T16:00:00Z

Similarly, I need to run Post scripts. In this example I am decoding a base64 document reply that returns multiple labels in an array:

var allLabelBuffers=[];
var totPackageCount = (jsonData.output.transactionShipments[0].pieceResponses.length)
var packageCount = 0

for (var packageCount; packageCount < totPackageCount; packageCount++) 
                  {
                   var newLabelBuffer = (jsonData.output.transactionShipments[0].pieceResponses[packageCount].packageDocuments[0].encodedLabel)
                     allLabelBuffers.push(atob(newLabelBuffer))
                   }

       allLabelBuffers = JSON.stringify(allLabelBuffers)

pm.environment.set("labelBuffer", allLabelBuffers); 

The atob(newLabelBuffer) decodes the base64 to actual document language. In this case it is a Zebra ZPL printer code.

Having the ability to run code prior to an API Request and after an API Reply would be extremely helpful. It would also give me an alternative to Postman should I need it.

Thank you.

[rangav]

Hi @smiller0924
Pre and Post request scripting is possible with filters

see docs here
https://github.com/rangav/thunder-client-support/blob/master/docs/filters.md

let me know if you have any questions

[rangav]

Thanks, Happy new year to you.

you can also you filters in Tests, see 3rd test in the image below.
https://github.com/rangav/thunder-client-support/blob/master/docs/filters.md#filters-in-tests

[rangav]

Set env variable in tests docs
https://github.com/rangav/thunder-client-support#setenv

[smiller0924]

Ok. I think I kind of understand the "Pre-"

How do I extract specific header values from an array. Ex: I'm getting 5 separate Base64 label replies.

How do I create a "count" set the "Do While...". Then feed each decoded (atob) ZPL reply separated into an Environmental Variable?

Thank you.

[rangav]

I don’t have access to laptop now, will provide example later tomorrow

but let me try to explain
You use the custom logic in filter and decode the value and return the value in the function

in tests
Create test using set env variable and use the above filter

example json | customerFilter

[smiller0924]

So I call the custom filter. Then it parses the Jason response. Then my script gets executed. The values in for Do While Loop populate my environmental variable.

If that the basic idea? If so, an example would be helpful toward pointing me in the right direction.

Thank you very much.

[rangav]

Here are the steps

1. Create script file

2. Attach script to collection settings

3. Create a test using Set Env Variable option

4. Apply the custom filter decodeFilter

• The response body is passed to filter using the json keyword

6. Create an environment, if you haven't already created.

6 Run the request and see if its working or not, see also logs for any errors

[smiller0924]

Thank you for this. This is very helpful.

I do have one question. I noticed you crossed out the "atob" that decodes my Base64 reply. Why did that need to be done? Shouldn't I run the decode in the script and send the unencoded header value to the environmental variable?

Please clarify. Thank you again.

[rangav]

Vscode did that not me, just saying it’s deprecated in node.

[smiller0924]

Ok. One more question. Which library are you running to generate the node.js. The examples I provided are from Postman. Which I believe uses 'C'.

Sorry for all the questions. Just trying to get a good handle on this function.

Thank you.

[smiller0924]

Sorry. The code is in Java. Not 'C'.

[rangav]

The extension is built on node.js and JavaScript.

the same code should work in Thunder Client too.

Have you tested the script?

[smiller0924]

Ok. I have tested you suggestions. It is not parsing out the Label Buffers. It is instead returning the entire JSON Response Body as well as the filters.js as you recommended it be written. (I have zipped the response as the upload does not support .json or .js extensions). It does not appear to be running the script at all from the function from the filters.js. In fact it is ignoring the filter is even there.

Any thoughts you have would be helpful. Thank you.

filters.zip
REST_RESPONSE_BODY.zip

[smiller0924]

I did add the json. in front of "output...". Still no result:

[rangav]

Thanks for sharing response body, will test and get back to you with a solution

[rangav]

How did you unzip the response in Postman? Can you share complete script you used?

[smiller0924]

Here is the exact script from Postman Test module:

`var jsonData = JSON.parse(responseBody);

pm.environment.set("shipDate", jsonData.output.transactionShipments[0].shipDatestamp);
pm.environment.set("serviceType", jsonData.output.transactionShipments[0].serviceType);

var allTrackingNumbers=[];
var totPackageCount = (jsonData.output.transactionShipments[0].pieceResponses.length)
var packageCount = 0

for (var packageCount; packageCount < totPackageCount; packageCount++)
{
var trackingNo = (jsonData.output.transactionShipments[0].pieceResponses[packageCount].trackingNumber)
allTrackingNumbers.push(trackingNo)
}

   allTrackingNumbers = JSON.stringify(allTrackingNumbers)

pm.environment.set("trackingNo", allTrackingNumbers);

**_var allLabelBuffers=[];
var totPackageCount = (jsonData.output.transactionShipments[0].pieceResponses.length)
var packageCount = 0

for (var packageCount; packageCount < totPackageCount; packageCount++)
{
var newLabelBuffer = (jsonData.output.transactionShipments[0].pieceResponses[packageCount].packageDocuments[0].encodedLabel)
allLabelBuffers.push(atob(newLabelBuffer))
}

   allLabelBuffers = JSON.stringify(allLabelBuffers)

pm.environment.set("labelBuffer", allLabelBuffers);_** `

Needless to say the Bold/Italicized sections are what I have been focusing on with you. Here is an image from Postman:

I hope this helps. Let me know if you have any questions.

[smiller0924]

One other thing I noticed. I get a 'lightbulb' by the line, "exports.decodeFilter = decodeFilter;" It make a recommendation to, "Convert to an ES Module". If I select that then it conversts "exports.decodeFilter = decodeFilter;" to:

const _decodeFilter = decodeFilter;
export { _decodeFilter as decodeFilter };

I've tried that modification. It seems almost as if the "json | decodeFilter" is completely ignoring the "decodeFilter" and just pushing the entire reply into my variable.

[rangav]

you should only use module.exports = [decodeFilter], our internal code parser expects this.

[smiller0924]

Ok. This is exactly what I have in my filters.js:

`function decodeFilter(json) {
var allLabelBuffers = [];
var totPackageCount = (json.output.transactionShipments[0].pieceResponses.length);
var packageCount = 0;

for (var packageCount; packageCount < totPackageCount; packageCount++) {
    var newLabelBuffer = (json.output.transactionShipments[0].pieceResponses[packageCount].packageDocuments[0].encodedLabel);
    allLabelBuffers.push(atob(newLabelBuffer));
}

allLabelBuffers = JSON.stringify(allLabelBuffers);

//pm.environment.set("labelBuffer", allLabelBuffers); 
return allLabelBuffers;

}
module.exports = [decodeFilter];`

[rangav]

Its working now, atob module is not available in Thunder Client.

Code:

function decodeFilter(json) {
    var allLabelBuffers = [];
    var totPackageCount = (json.output.transactionShipments[0].pieceResponses.length)
    var packageCount = 0

    for (var packageCount; packageCount < totPackageCount; packageCount++) {
        var newLabelBuffer = (json.output.transactionShipments[0].pieceResponses[packageCount].packageDocuments[0].encodedLabel)
        allLabelBuffers.push(Buffer.from(newLabelBuffer).toString())
    }

    console.log("allLabelBuffers", allLabelBuffers);

    allLabelBuffers = JSON.stringify(allLabelBuffers)

    // pm.environment.set("labelBuffer", allLabelBuffers);
    return allLabelBuffers;
}

module.exports = [decodeFilter];

[rangav]

since you already using custom script, you can decode in the script itself.

allLabelBuffers.push(Buffer.from(newLabelBuffer, "base64").toString())

[rangav]

here is the updated script with base64 decode:

function decodeFilter(json) {
    var allLabelBuffers = [];
    var totPackageCount = (json.output.transactionShipments[0].pieceResponses.length)
    var packageCount = 0

    for (var packageCount; packageCount < totPackageCount; packageCount++) {
        var newLabelBuffer = (json.output.transactionShipments[0].pieceResponses[packageCount].packageDocuments[0].encodedLabel)
        allLabelBuffers.push(Buffer.from(newLabelBuffer, "base64").toString())
    }

    allLabelBuffers = JSON.stringify(allLabelBuffers)

    // pm.environment.set("labelBuffer", allLabelBuffers);
    return allLabelBuffers;
}

module.exports = [decodeFilter];

[smiller0924]

That got it! Thank you so much for working with me. I understand you product much better. This is seriously cool!

Thank you again and have a Happy New Year!

[rangav]

You are welcome, Happy New Year 🎉

Feel free to reach out if you have any further questions.

[smiller0924]

Like I said this was definitely cool. I'm looking for an alternative to Postman. This definitely got my vote!

[smiller0924]

I had another thought (yes, that's a dangerous thing with me). Can I use one of the Post-Script events to create a .js script that would print my decoded ZPL buffer directly to a printer instead of sending it to a variable?

[smiller0924]

Postman cannot execute printing outside of the application. The best I can do is call an API from Labelary to display a label image. I'd like to push the label to a shared printer connected to my PC and Postman does not support this.

[rangav]

you can use if there is any node modules that support this.

To import node module
https://github.com/rangav/thunder-client-support/blob/master/docs/filters.md#import-node-module

[smiller0924]

What would that look like in the Test section. How does it get triggered?

[rangav]

You need to create a dummy/fake test for this purpose

same steps as here
#955 (comment)

Instead of selecting Set Env Variable, you can select Json Query

Your custom script just returns the same json back

[smiller0924]

Ok. I'll play with that. Thank you.