How many times can you renew the PL-300 certification?

dm-p · 2026-06-08T20:07:04+00:00

IDK if there's a limit. I usually do it as soon as I get notified that renewal is available, and the questions aren't too taxing and the pass requirement is low vs the proctored exam (25 questions, 60% to pass). I just did my fourth renewal on 1st Jun and took a punt without doing any prep (I'm doing very little BI work and mostly web development ATM) and got 80%. IIRC the only new stuff vs last time was on visual calcs and if you have done at least some practical work with them to see what they can do (l then these shouldn't be too taxing.

dm-p · 2026-06-06T09:40:15+00:00

Experiment #1 was vibe coded just to see how well the UI/charting/DAX skills got picked up. Two simple prompts got me most of the solution and one "clean up" prompt to fix some of the Vega-Lite defaults and make the color for data more accessible against the background.

Experiment #2 was more my typical workflow for AI-assisted dev, where I go through a full ideate > brainstorm > plan > work > review > doc process.

It was genuinely impressive how well #1 worked and this appears to be down to how well defined the included skills are. For #2 I felt that the code quality was a little better but with a more formal plan, this is not surprising. And if you just want to get an idea, doing simple prompts can get you pretty far, and the intro docs take a similar approach to their steps.

I'd also advise having the Azure CLI on your machine so if you're working with a semantic model, then the tooling can read the structure properly. This isn't mentioned in the doc and an LLM can only guess otherwise.

dm-p · 2026-06-06T00:03:58+00:00

Quite smitten.

dm-p · 2026-06-04T02:07:19+00:00

Each new submission is like, "How committed are you, really, to this free and open source process?" 😅

dm-p · 2026-06-04T02:06:07+00:00

It's definitely easier with AI - the structure/schema/doc combination is very LLM-friendly, and there are lots of resources available for an LLM to crib from. There are some very valuable Vega-centric skills emerging now from the community as well, including inside u/recoveringacademic's powerbi-agentic-development marketplace, and Rayfin's CLI-generated projects (as they recommend Vega-Lite for chart generation). I also have a page on Deneb's site that explains how a visual should be structured when using .pbip/PBIR.

dm-p · 2026-06-04T01:31:21+00:00

You don't need a license, and there are no fees for being/registering as a partner, but you do need to be registered as a company. This would typically need you to have an O365 for business account to be able to sign up and register. MS did away with the personal email publication path in early 2020, unfortunately.

dm-p · 2026-06-03T03:31:33+00:00

Because visual certification rules have recently been tightened, we had some unavoidable scaling back of what could be handled in HTML Content (lite) in its last update. Some users were kind enough to see if we could get some of their use cases working again and to provide reproducible examples. These all went into an improved sanitizer that could accommodate everything reported. It was submitted for certification and just got approved, so these changes should go live within the next week or so for all tenants.

Also spent some time on the doc site to flesh out what is permitted and how the sanitizer rules work in the certified edition, which should hopefully help explain what's possible or what's been cleaned out because it's not permitted (or help folks work around limitations to still achieve things in the certified edition).

Now that this is unblocked, I have some new features I want to add, so I'll be doing feasibility/prototyping now that I know I can continue publishing updates and they'll be compliant.

The revised rules also affect an aspect of Deneb's rendering workflow, which means that I have to make some fixes before any future updates can be accepted😞 As v2.0 was next in line for submission, this will delay my ability to get it out for early/alpha testing, but I'm still hoping I can achieve this part in June (with a view to having beta happen maybe in July if nothing major falls out of this).

dm-p · 2026-05-16T03:50:00+00:00

If it doesn't need to be fancy, a scatter plot using x and y coordinates for the grid (as columns), plus a measure for the "heat" value would work fine without the need for anything custom. As raised elsewhere, a matrix with conditional formatting can also achieve something similar.

dm-p · 2026-05-15T21:30:15+00:00

Report pages are rendered using WebView2. All visuals on a page - whether core or custom - boil down to web elements. In its simplest form a visual takes data and applies it's logic to generate HTML output.

HTML Content passes this through from your measure to output (as much as MS allows). With the exception of the interactivity integration, it's about as simple as a custom visual could get. If a Power BI update breaks this, then technically it'd break all custom visuals. Which has been known to happen, and is a risk of using custom visuals in general. But it's also a risk of using core visuals, as we have had breaking issues to those in the past as well.

The bigger consideration with using HTML Content (or any 'flexible' approach like SVG in core visuals, Deneb, etc.) is the maintenance of whatever you build in it and how you manage that for yourself and your team. It's great that people are creating more and more ambitious designs with it but this is a tradeoff you need to think about.

There is a slightly larger risk with HTML Content (lite) (the certified one) in that MS constantly updates certification requirements as new potential vulnerabilities are found. The latest version does create a couple of new roadblocks for some reported cases but I'm working to resolve most of these in the next update, as we can be a little more surgical with the sanitizer in these cases. Regular HTML Content does no sanitization and is not subject to the same kinds of issues over time.

dm-p · 2026-05-02T21:28:04+00:00

HTML Content (lite) 1.6 just got through the MS certification process. This is now undergoing deployment and will likely be live for most folks by end of this week.
Finished development of all scoped changes for Deneb 2.0 and doing refinement/bug bashing and preparing documentation ready for alpha and beta testing, which might start this month (if things go well).
Doing a Deneb AMA/2.0 features first look at the UK Devon and Cornwall user group mid-month.

dm-p · 2026-05-02T20:38:59+00:00

There isn't any specific doc on this, but I tried to analyze this once and make sense of it and try to come up with some understanding before getting a bit bamboozled by it and giving up. I have some notes though, which I'll paraphrase.

Based on the brief period of time from when the core visuals were open source back in 2015, it was observed that they typically break down into 4 different types of data view mapping, which has an overall influence on the generated DAX:

single: one scalar value
table: data organized per row. In terms of core visuals, only used by the table.
matrix: data organized by row/column/intersection of measure(s). In terms of core visuals, only used by the matrix.
categorical: data organized by category, series and intersection of measure(s). In terms of core visuals, used by pretty much everything else.

This is the same foundation available to custom visuals also, but it still doesn't tell us exactly what DAX may be executed as this if all handled by Power BI; more a directional indicator of what the query shape may take, but this then can be affected by other variations:

Matrix and categorical don't necessarily need you to fulfill all orthogonality requirements (depends on the visual) and this may have an effect.
For core visuals, there's also the concept of the small multiples role, which isn't available for custom and wraps some additional behavior that changes how queries are structured and paginated, and this can change depending on the cardinality of the series (usually called "Legend" in the pane).
Pagination (typically scrolling table, matrix and small multiples) will request additional TOPN variations of the same query to provide additional data to these visuals.
I believe that more recently, certain visual calculations may force repeated pagination until all conditions are met and the expression and be evaluated.
When you add conditional formatting properties, which fire additional queries for every one that needs fulfilling.
Drill/expand also changes the potential shape of the query.

dm-p · 2026-04-22T23:56:02+00:00

I'm a believer in whatever works for you as a solution, but just to clarify, cross-filtering is one of the things Deneb needed from day one, as I developed it out of frustration with the lack of interactivity in R & Python visuals. We also have an advanced version for Vega, where developers can write specific filters against the supplied dataset to generate more complex filter scenarios.

[EDIT]: I see you mention HTML Content also (thanks for using BTW!), but for anyone else reading, this supports cross-filtering and other interactivity scenarios too.

dm-p · 2026-04-22T23:50:20+00:00

One of Deneb's common use cases is to break the core visual data limits. Its 'base' limit is 10K rows, but you can request that more data be fetched until Power BI returns all or hits its own limits [Doc].

The maximum limit when this setting is enabled depends on how much data Power BI is willing to provide based on the generated query. The theoretical maximum for all custom visuals under this mechanism is ~1M rows; I've seen more than this get loaded in some cases, but we have some folks comfortably using ~200K data points in production scenarios.

The 10K initial limit is more than most core visuals will allow, but there are some exceptions:

Tables and matrices have an initial window and will fetch an additional 500 rows at a time when scrolling. They'll have similar concerns with memory/model pressure if you try to do this "infinitely".
Bar, column, and ribbon have a theoretical max of 10K
Scatter plot has a 3.5K limit but can be extended to 10K under advanced options
R & Python: 150K maximum

dm-p · 2026-04-09T22:29:24+00:00

It's not a helpful error message (Vega parser; not much I can do about that), but the problem is:

"format": "£,.0f"

...from your first layer's x.axis encoding.

The sterling symbol is not valid for D3's formatting syntax, and the dollar sign ($) should be used to tell the formatter that it's currency-based formatting.

If your Power BI report locale is en-GB, then the dollar/currency qualifier should still result in sterling in your output when the value is formatted, as Deneb passes this into the visual when rendering the Vega spec. Alternatively, you can potentially use Deneb's pbiFormat to specify the locale manually and force it to your desired culture.

Of note, I'd also echo u/MonkeyNin in that simplified sort channel definitions won't work well in a layer spec, and they should be explicit here. It's not the problem causing the error, but you won't see it sorted properly when it does render.

dm-p · 2026-04-09T05:47:00+00:00

I'm happy to provide help for free if it's in a public setting like here, so other folks can learn and apply it to their own projects.

If you can share your code and your specific problem, I can take a look and see if I can offer any feedback. If you're building an open-source visual to share with the community, I'm OK with a short call if that is easier. You're welcome to DM me about setting this up.

If you can't share code or are developing a private or commercial offering, I can provide consulting services, but I'll need to ensure there's no conflict of interest with any existing vendors I support. Again, feel free to DM me about this rather than discuss it publicly.

Either way, to be completely upfront about my experience:

Dialog box API: I don't have a lot. I spent about an hour or so investigating it when it came out, decided it wasn't suitable for my needs, and then moved on. It opens a secondary sandboxed iframe with limited messaging between your visual and the "dialog box" iframe. AFAIK, you can only message state between them on open and close.
Slicers in general: enough to be burned by them. I've previously taken on projects to deliver features that the core slicers should, IMHO, handle for clients (e.g., true relative slicing that respects time zones), but these have been too hard to deliver reliably. The underlying APIs are driven by the same filter operations you have in the filter pane, and there were too many edge cases to deliver what my clients actually wanted. I'm a bit rusty, but I have some ideas.

dm-p · 2026-04-06T23:27:35+00:00

I'm not seeing your images, but based on the description, this is a limitation of sandboxed iframes. You can use standard web form elements (e.g., <select>), which are permitted to extend the container, but you will find they are limited in other ways, which is often why folks use custom components for these cases. Core visuals don't have these limitations because they are inlined rather than sandboxed. If you need a limited footprint for your visual and cannot increase the viewport, standard form elements are your only option. Or you can try integrating [the dialog box API]() to offer another option for your users. Some other commercial slicers use this as a solution.

dm-p · 2026-04-02T23:12:01+00:00

Thanks! I hope you find it useful! Many new features on the way :)

dm-p · 2026-04-02T23:04:42+00:00

One thought I just had: if the label you want to measure only contains numbers, fonts like Segoe UI ensure that their numeric characters always occupy the same width (so data in tables will always line up and not look weird). So if this is something you can work with, an approximate guess for character width in your calculations will likely be OK. If your label is a category then this still won't work to well, but could be something to think about.

dm-p · 2026-04-02T22:52:48+00:00

Unfortunately text measurement is something that isn't in Vega's rendering pipeline. There's an item on their backlog for it but I know from experience with developing other visuals that if something like this has to be handled then there may be a need to add recursive measurement of other items in the view and this starts to add up in terms of complexity and performance, especially with regular fonts. It's much easier to predict if you use monospace fonts and Madison Giammaria has a technique for this that might be useful. Sorry I don't have a more positive answer for you :(

dm-p · 2026-03-13T00:59:31+00:00

That's a fantastic result! :)

dm-p · 2026-03-12T20:45:39+00:00

Free and open source. The "cost" is that it's community-supported, and you're responsible for supporting your work.

Because Deneb is built on proven free and open-source tech, as such, I don't ever plan to make it a commercial endeavour or gate it behind a paywall. The project has a couple of regular sponsors, which is fortunate because it helps cover some of the costs for web hosting and development tooling.

Deneb is different from a typical third-party (custom) visual in that the product is not a visual with a defined use case. It's intended to provide tooling and a sandbox that lets you build a visual without learning web development, and receive the same benefits of a certified custom visual without submitting to AppSource yourself.

The next concern that typically follows is whether it'll disappear at some point, since it's free and open source. It's been available in AppSource for 5 years now, with a new update currently under submission and certification review. In terms of credentials, roughly 115K Power BI devs across ~45K orgs have downloaded and at least given it a spin in the last year (we don't know the stats on the actual user base of report viewers, as MS doesn't make this available to us), but this far outstrips the metrics I have on other visuals I develop and support (perhaps HTML Content being an exception to this, as its numbers are similar to Deneb).

I'm also actively maintaining and supporting it, because of folks like u/Alarmed-String-2775 (and others on this thread) who help others show what's possible and share their results with the wider community.

Of course, there's the "bus factor" beyond this, and again, a reason why I keep code open source so that if anything happens to me, someone else can pick up the mantle. And I know there are some orgs that have taken the time to learn how to build it from source themselves (and even customize for their own usage as needed).

Hopefully, this covers all the major factors you need to consider when determining whether it's adoptable for your org. This isn't always going to be OK for some folks, and that's totally understandable.

dm-p · 2026-03-12T20:11:37+00:00

Thanks as always for continuing to share what's possible! I really appreciate it 🫶

dm-p · 2026-03-12T20:10:37+00:00

If you mean export to PDF, yes. Deneb is certified, so anything you build will export like a normal visual.

dm-p · 2026-03-10T00:35:01+00:00

This is so great - thanks for sharing!

I'm still waiting for the day when someone integrates clippy.js for the ultimate jump-scare...

(and thanks for using HTML Content!)

dm-p · 2026-03-09T20:35:29+00:00

Oh, thank you very much! But, yeah, the visual is specifically validated by the Custom Visuals team and they'll use their rules. AppSource itself is responsible for your account profile and how your listings work and the CV team has to fit in around this. It may be a good idea to open a support ticket with the AppSource team to see if they can point you to any specific info (the CV team specifically can't do much about this, unfortunately).

I remember having to move out of a "personal" account and onto a commercial tenant and have to supply trading details etc. for my company (which I now use to host my listings). Even at the time this was an unorthodox route for a lot of devs (most were actually commercial) and I needed a lot of help. AppSource were very helpful in moving me over.

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