Add slugify as a template filter

[ZephireNZ]

Proposed change

This adds a slugify filter for templates. This is useful, for example, if you have a string and want to translate it to a entity_id.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request: Add documenation for slugify template filter home-assistant.io#20069

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• Tests have been added to verify that the new code works.

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[tdejneka]

Thank you! It's a long-standing Feature Request:
https://community.home-assistant.io/t/slugify-please/224879

[frenck]

@ZephireNZ A wild merge conflict appeared out of nowhere! 🙈
Could you take a look?

[emontnemery]

Just out of curiosity, how is this intended to be used?
There's no guarantee an entity's entity id is identical to a slugified version of its name etc.

[ZephireNZ]

Fixed merge conflict, did it in the GitHub UI so here's hoping I've not messed up the formatting checks 😅

[ZephireNZ]

Just out of curiosity, how is this intended to be used? There's no guarantee an entity's entity id is identical to a slugified version of its name etc.

My use case:

I want to create an automation that changes my lights to a scene I created previously, based on the TV show playing.

Now, I could create a buuuunch of case statements in that automation, each with their own service call for specific lights/scenes, but that's very tedious to say the least.

As far as I could tell, there's no simple way to find an entity based on its name - so my idea is to do the same slugification of the show name, and check if a scene entity existed with that id. If for some reason scene.friends is actually scene.friends2, I can easily fix that manually.

I am sure there are other use cases too, but that's my own.

[ZephireNZ]

@frenck all good to merge now 😊

[balloob]

States have a name attribute:

{{ states.light.desk_lamp.name }}

[emontnemery]

@ZephireNZ The use case you describe has the problem I mentioned: There's no guarantee that an entity's entity_id is the slugified form of it's name:

• If the entity is not in the entity registry, the entity_id is not guaranteed to be stable across restarts of Home Assistant
• If the entity is in the entity registry, the entity_id can be changed by the user from the frontend

Edit: Your example use case should be solved by looping over the available scene states, finding the scene with the right name.

[frenck]

I agree that the use case is incorrect and probably not the best example for advertising/adding a feature.

[ZephireNZ]

@tdejneka what was your use case?

[frenck]

Rebased the PR to deal with a merge conflict.

[frenck]

Ok, so the use-case described is wrong. You should not use the slugify method to "guess" entity IDs (there are many other method for that as shown above).

Nevertheless, we have discussed this on Discord and there are some cases where this can be useful. E.g., when needing an action key based on a title in an actional notification; working with REST APIs.

The use cases for these are fairly limited, but this addition is fairly clean as well.

Therefore accepting this addition. Thanks @ZephireNZ 👍

[ZephireNZ]

Thanks! I knew it was a useful addition, just couldn't come up with a good example use case 😅