# How to get the value of the parameter passed to a page

**URL:** <https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055>\
**Category:** How-to Discussions\
**Created:** [October 27, 2017, 12:10pm UTC](https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055 "2017-10-27T12:10:19Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![papakay19](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/papakay19/32/510_2.png) [@papakay19](https://forums.fusetools.com/u/papakay19)\
**Post date:** [October 27, 2017, 12:10pm UTC](https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055/1 "2017-10-27T12:10:19Z")

</div>

Hello, please i have a code snippet similar to below. I’m unable to get the data with the map function.

```auto
	<JavaScript>
		var Observable = require("FuseJS/Observable");
		var Context = require("Modules/Context");
		
		var bankNameRegion = Observable();
		var tellerNumber = Observable();
		var amount = Observable();
		var errorMessage = Observable();

		var transaction = this.Parameter;
                var transactionId = transaction.map(function(x) { 
                    console.log(x.TrnsID); 
                    return x.TrnsID; 
                });

		
	</JavaScript>

	

```

When i logged the the data using `console.log(transaction);` i got

```auto
{"_origin":-5162,"_subscribers":[],"_isProxy":true,"_values":[],"_subscriptionWatchers":[{"watcherId":218}]}

```

Interestingly i was able to access the data in the UX for instance `<Text Value="{transaction.TrnsID}"/>` works well.

---

<div class="post-metadata">

**Author:** ![papakay19](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/papakay19/32/510_2.png) [@papakay19](https://forums.fusetools.com/u/papakay19)\
**Post date:** [October 27, 2017, 12:13pm UTC](https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055/2 "2017-10-27T12:13:23Z")

</div>

I forgot to add that the map function was never called.

---

<div class="post-metadata">

**Author:** ![Uldis](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/uldis/32/657_2.png) [@Uldis](https://forums.fusetools.com/u/Uldis)\
**Post date:** [October 27, 2017, 12:57pm UTC](https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055/3 "2017-10-27T12:57:05Z")

</div>

`.map` returns a derived Observable, which means that it must be _consumed_ for it to be calculated. Please read about [Observables](https://www.fusetools.com/docs/fusejs/observable) and see the [Observable API](https://www.fusetools.com/docs/fusejs/observable-api) to find out what “consumed” means in this context.

---

<div class="post-metadata">

**Author:** ![papakay19](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/papakay19/32/510_2.png) [@papakay19](https://forums.fusetools.com/u/papakay19)\
**Post date:** [October 27, 2017, 1:07pm UTC](https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055/4 "2017-10-27T13:07:19Z")

</div>

Thanks so much for your response. I’ve already gone through and did that again but can’t really get a way out of the retrieving the details. Is there any other way of get values out of a parameter outside map. Can’t i just use key to call for the value stored against the key.

This is really giving me a great concern.

---

<div class="post-metadata">

**Author:** ![Uldis](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/uldis/32/657_2.png) [@Uldis](https://forums.fusetools.com/u/Uldis)\
**Post date:** [October 27, 2017, 1:15pm UTC](https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055/5 "2017-10-27T13:15:51Z")

</div>

Well, [this part in Tutorial](https://www.fusetools.com/docs/tutorial/navigation-and-routing#sending-data-between-our-pages) covers passing properties and receiving them. Please take the whole tutorial if you haven’t yet.

The [link I shared before](https://www.fusetools.com/docs/fusejs/observable#subscribing-to-changes-in-observables) says, explicitly: `A really important thing to understand about Observables is that they need at least one subscriber before they start propagating data. There are a few ways to subscribe to an Observable.`. Subscribe to it then?

Currently, it is _vital_ to understand how to work with Observables correctly. Please invest the time. We are also working on an alternative that would allow us to write simple, plain ES6 JavaScript (without Observables), but that is still some way out without an ETA.

---

<div class="post-metadata">

**Author:** ![papakay19](https://yyz1.discourse-cdn.com/flex035/user_avatar/forums.fusetools.com/papakay19/32/510_2.png) [@papakay19](https://forums.fusetools.com/u/papakay19)\
**Post date:** [October 27, 2017, 1:41pm UTC](https://forums.fusetools.com/t/how-to-get-the-value-of-the-parameter-passed-to-a-page/4055/6 "2017-10-27T13:41:30Z")

</div>

Thanks Uldis for the life saving information. I now have a deeper understanding of Observables. I was able to make it work following the information you shared.

Thank you!