# Tag History Binding Indirect tag addressing help

**URL:** <https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [October 21, 2022, 4:30pm UTC](https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537 "2022-10-21T16:30:15Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Drew.Gatti](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/drew.gatti/32/39854_2.png) [@Drew.Gatti](https://forum.inductiveautomation.com/u/Drew.Gatti)\
**Post date:** [October 21, 2022, 4:30pm UTC](https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537/1 "2022-10-21T16:30:15Z")

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Hey Everyone,

Can someone help me with this tag history binding?  
Here is what I'm doing:

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/d/ad7f4c8cf08145de381fe1557021e334718fc5bf.png)

Here is what {view.params.Name}+"/status/encoderposition" evaluates to:  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/3/d3a05dff58b0c221e7837afc1ba97067cd6ef29b.png)

I tried building the array in the expression language but it kept complaining about my brackets.

Thank you,  
-DG

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**Author:** ![djs](https://avatars.discourse-cdn.com/v4/letter/d/e47774/32.png) [@djs](https://forum.inductiveautomation.com/u/djs)\
**Post date:** [October 21, 2022, 5:03pm UTC](https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537/2 "2022-10-21T17:03:06Z")

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You'll want to define a custom property with this structure:

- **key** [array]
  - **[0]** {object}
    - **aggregate** value
    - **alias** value
    - **path** value

  - **[1]**{object}
    - **aggregate** value
    - **alias** value
    - **path** value

  - ...

And then bind to it in the expression.

read the _Using Dynamic Tag Paths_ example under this [link](https://docs.inductiveautomation.com/display/DOC80/Tag+History+Bindings+in+Perspective).

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<div class="post-metadata">

**Author:** ![Drew.Gatti](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/drew.gatti/32/39854_2.png) [@Drew.Gatti](https://forum.inductiveautomation.com/u/Drew.Gatti)\
**Post date:** [October 21, 2022, 5:17pm UTC](https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537/3 "2022-10-21T17:17:55Z")

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I guess a better description of my problem is I cant concat in expression language and create a json.  
Like this: jsonFormat([{"path": "concat({view.params.Name},"/status/encoderposition")"}])

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<div class="post-metadata">

**Author:** ![Drew.Gatti](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/drew.gatti/32/39854_2.png) [@Drew.Gatti](https://forum.inductiveautomation.com/u/Drew.Gatti)\
**Post date:** [October 21, 2022, 5:45pm UTC](https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537/4 "2022-10-21T17:45:34Z")

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I dont know if there is a better way to do this in the expression language but I built the JSON as a custom property and just bound to it in the tag history expression.  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/4/a42ecf0757189a695d94f554ad65154fe249cc89.png)

It would be nice to do this just in the expression language but i couldn't figure out how to concat a view parameter and build a JSON at the same time.

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**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [October 21, 2022, 6:02pm UTC](https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537/5 "2022-10-21T18:02:42Z")

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Yeah, the expression language doesn't have any ability to declare a json object or array. We considered it a while back, but decided it wasn't worth the complexity cliff. A custom property is pretty much the way to go here.

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<div class="post-metadata">

**Author:** ![Drew.Gatti](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/drew.gatti/32/39854_2.png) [@Drew.Gatti](https://forum.inductiveautomation.com/u/Drew.Gatti)\
**Post date:** [October 21, 2022, 6:20pm UTC](https://forum.inductiveautomation.com/t/tag-history-binding-indirect-tag-addressing-help/65537/6 "2022-10-21T18:20:34Z")

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I'm surprised there isn't something like this:  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/1/a1d65b9afa79b2861258f72d4e492df6ff46f977.png)

I was just surprised to not see an "indirect" radio button. Seems like a necessary addition.