# Merge readBlocking into getConfiguration for "default" or expression-derived properties?

**URL:** <https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421>\
**Category:** Ignition\
**Tags:** scripting\
**Created:** [March 22, 2023, 2:17am UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421 "2023-03-22T02:17:32Z")\
**Posts on this page:** 13\
**Page:** 1

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**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\
**Post date:** [March 22, 2023, 2:17am UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/1 "2023-03-22T02:17:32Z")

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Anyone know if there's an IE resource (or otherwise) for merging results of readBlocking list into a getConfiguration dict? I have a fairly ugly method, but interested to see other methods (or even rationales NOT to do this).

my method is roughly:  
getConfig (recursive) \> list of tags with appended .properties I want to resolve \> readBlocking \> 2D list \> dict with full tag path as key \> update getConfig items.

Fairly nervous to post my actual code and show the world how ugly and brute-force it is. Hoping some with better coding practices than I might share their solutions.

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**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [March 22, 2023, 2:40pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/2 "2023-03-22T14:40:25Z")

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> [@hunterdg](#):
>
> list of tags with appended .properties I want to resolve

Are these non-default properties that are returned by getConfig() or are they a list of properties that you're interested in but the tags (for whatever reason) don't have them set?

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<div class="post-metadata">

**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\
**Post date:** [March 23, 2023, 3:06am UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/3 "2023-03-23T03:06:51Z")

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They’re either _default_ properties that getConfig doesn’t return, or properties that perhaps have an expression relying on UDT parameters

For example opcItemPath is always dynamic for my current project, based on parameters. getConfig returns the parameter expression

```auto
{opcServer}/{device}/{path}

```

, but readBlocking on tag.opcItemPath returns the actual resolved/evaluated path.

```auto
Srvopc/tank/level

```

I suppose I could override missing/_default_ getConfiguration properties with their default static DataTypes via

```auto
from com.inductiveautomation.ignition.common.sqltags.model.types import DataType
for tag in system.tag.getConfiguration(‘[provider]Folder/UDTInstance’)[0][‘tags’]
    dataType = tag.get('dataType', DataType.Int1)

```

But that requires me to make a list of every default property since .GetOrDefault doesn’t appear to be a thing in 8.x anymore, unless I’m mistaken.

Sure I could create a function for that but readBlocking seems easier and more derivative/foolproof

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**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [March 23, 2023, 8:16am UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/4 "2023-03-23T08:16:51Z")

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That sounds like my kind of fun, but I'm not sure what you're trying to do. Or rather, why you're trying to do it. What's the goal here ?

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<div class="post-metadata">

**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [March 23, 2023, 1:08pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/5 "2023-03-23T13:08:54Z")

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I guess, I'm not entirely certain what the output that you're looking for is. Can you provide an example of the output that you're looking for after this function has ran?

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<div class="post-metadata">

**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\
**Post date:** [March 23, 2023, 4:03pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/6 "2023-03-23T16:03:13Z")

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getConfiguration only returns _non-default_ properties, and returns the 'raw' parameter expression string for any tag properties that are defined by expressions (see the opcItemPath example above)

I effectively want a function like getConfig but that _does_ include default values **and** resolves/evaluates any parameter-expression-defined tag properties.

So:

> 1. _insert_ any missing _default_ properties into the getConfiguration result dictionary
> 2. _update_ any parameter-expression-defined properties in the getConfiguration result dictionary

This kind of thing was easily handled in 7.9.16 with combination of `system.tag.browseConfiguration()` + `tag.getOrDefault('engUnit')`

I've begrudgingly pasted my hacky solution below - please go easy on me. 🙂  
In this case I'm updating/overwriting the getConfiguration .engUnit and .opcItemPath dict .values with those same values returned by readBlocking.

I also think my tagPath\_eval is slowing the script down significantly, but haven't confirmed. A different version not using eval() seems to work way faster.

```auto
p3 = shared.profiler.Profiler("siteConfigs"); p3.start()
siteConfigs = [system.tag.getConfiguration(sitePath, True) for sitePath in sitePaths if system.tag.exists(sitePath)]
if debug: logger.info('siteConfigs = ' + str(len(siteConfigs)))
propsForResolution_dict = {'engUnit':'.engUnit', 'opcItemPath':'.opcItemPath'}
tagPath_eval =("\"%s/%s/%s\" % (siteConfig[0]['path'], UDT_instance['path'], tag['path'])")
tagPaths_dict = {tag:propsForResolution_dict for tag in [eval(tagPath_eval) for siteConfig in siteConfigs for UDT_instance in siteConfig[0]['tags'] for tag in UDT_instance['tags']]}
propPathsResolved_dict = {tagPaths_dict.keys()[i]: {propsForResolution_dict.keys()[o]: v for o, v in enumerate(row)} for i, row in enumerate(zip(*[iter([x.value for x in system.tag.readBlocking([tag + prop for tag, props in tagPaths_dict.items() for prop in props.values()])])]*len(propsForResolution_dict)))}
for siteConfig in siteConfigs:
	for UDT_instance in siteConfig[0]['tags']:
		for tag in UDT_instance['tags']:
			tag['engUnit'] = propPathsResolved_dict[eval(tagPath_eval)]['engUnit']
			tag['opcItemPath'] = propPathsResolved_dict[eval(tagPath_eval)]['opcItemPath']
logger.info(str(p3))

```

tag structure is `[provider]SiteFolder/UDTInstance/tags`  
.engUnit and .opcItemPath properties on each tag are defined by expressions referencing tag parameters (or a combination of parameters) rather than hardcoded

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<div class="post-metadata">

**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\
**Post date:** [March 23, 2023, 4:09pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/7 "2023-03-23T16:09:42Z")

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bit more context - the goal is to create a giant table with relevant parameters per column. It's scripted instead of bound because the table view is heavily customized

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<div class="post-metadata">

**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [March 23, 2023, 5:02pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/8 "2023-03-23T17:02:39Z")

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What does the `eval()` function look like?

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [March 23, 2023, 5:08pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/9 "2023-03-23T17:08:39Z")

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`eval()` is a python built-in.

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<div class="post-metadata">

**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\
**Post date:** [March 23, 2023, 5:22pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/10 "2023-03-23T17:22:14Z")

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> [@hunterdg](#):
>
> `tagPath_eval =("\"%s/%s/%s\" % (siteConfig[0]['path'], UDT_instance['path'], tag['path'])")`

just evaluates this string so I don't have to use it in 3 places - newbie attempt at consolidating code a bit.

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<div class="post-metadata">

**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\
**Post date:** [March 27, 2023, 2:36pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/11 "2023-03-27T14:36:48Z")

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Anyone know if there is _already_ a method to return the "default" of any given tag property _without_ readBlocking or making a custom function myself? I've been in the javadocs extensively, but haven't explicitly looked for this.

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<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [March 27, 2023, 2:48pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/12 "2023-03-27T14:48:22Z")

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Yes. Start here:

[https://files.inductiveautomation.com/sdk/javadoc/ignition81/8.1.1/com/inductiveautomation/ignition/common/tags/config/properties/WellKnownTagProps.html](https://files.inductiveautomation.com/sdk/javadoc/ignition81/8.1.1/com/inductiveautomation/ignition/common/tags/config/properties/WellKnownTagProps.html)

Note the `.getDefaultValue()` method.

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<div class="post-metadata">

**Author:** ![hunterdg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/hunterdg/32/67774_2.png) [@hunterdg](https://forum.inductiveautomation.com/u/hunterdg)\
**Post date:** [March 27, 2023, 4:08pm UTC](https://forum.inductiveautomation.com/t/merge-readblocking-into-getconfiguration-for-default-or-expression-derived-properties/71421/13 "2023-03-27T16:08:43Z")

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Thank you very much! That does indeed look familiar - I must've forgotten about it when I realized I needed to evaluate expression-derived tag properties in addition to getting default values.