Working with dmx and dmx-geomaps

So far working with dmx has been great. As an user it has endless applications and it is really useful. As a frontend developer is has been challenge in a very good way I think once you understand all the structure It is kind of addictive and also forces you to think differently in terms of semantic and associations. I really like the platform and strongly recommend it.
I’m sharing here some small stuff that came out.

  • In the address section you can include same country name and duplicate the addresses when using symbols on the name for example “México”, I guess this could also happen for other values. The thing is that I had the same country with two names exactly with the same characters, so two persons(dogs) that live in the same address are not associate, not according to semantic storage.
    Maybe is important to clear that certain criteria of languages and symbols should be use or even set countries name data(international) instead of typing the value.

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  • The link for Simon Williams – The Associative Model Of Data (book, 284 pages), Lazy Software, 2nd edition, 2002 no longer exist. (

  • Use geomaps without addresses
    In the scuba diving model i’m working on, I have the topic type “buceo” with sea coordinates (a fix) of a place where you can dive, so this is not an address, the geocoords can be add by creating a new association type.
    You can type in the coordinates in the format but the input field does not accept decimals. Even though you can entry the values and render the coords in the map, the field input has a red border indicating an error.

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  • This could happen. One of the certificates of my JDK expires and was related to access the openstreetmap search and get the address causing not generate the geoCoordinates
    So the solution is to import a new certificate in cacerts file or more easy remove and install a fresh JDK.

  • For some cases for example two dogs live on the same street but different houses(very far away from each other), but the open street map returns the same coords even with a different street number. It would be nice to implement the drag function of leaflet and move the geocoord to the exact place and update the mark for one dog.


Thank you very much for the questions and hints! I’m happy you like DMX and that it is useful for you. :smile:

To my understanding you’re saying that you can create the very same topic (e.g. a Country) twice, and that this violates DMX’s semantic storage principle. And you’re assuming that this is a bug, that could be related to special characters like é.

This would be indeed a bug. However I can’t reproduce it. I’ve entered 2 persons with the same address (… “México”). DMX then shares the corresponding Country (simple) and Address (composite) topics properly. Even if one moves from “Mexico” to “México” DMX rearranges the associations, and shares the topics properly.

What falsifies your hypothesis about special characters is that, according to your screenshot, a Region topic (“Estado de México”) is properly shared by DMX even it contains special characters.

In general DMX works with the Unicode character set, and to my experience DMX has no problems with special characters. You can even work with Chinese.

Anyways I’m keen to understand how you were able to create 2 (Country) topics with the very same name in the first place? Can you give a hint how to reproduce it?

At the moment you could try to delete one of the Country duplicate topics, and enter the Address again. Let’s see if the Country/Address topics are properly shared then.

Thank you very much for sharing your questions and hints!

Welcome to DMX!

The link is now updated:

Thank you very much for pointing out!

Meanwhile it occurred to me how the duplicate Country topic was possibly created. Namely in conjunction with multi-user operation and access control.

  1. Assume a fresh DB.
  2. User A goes to a private workspace and enters a “México” address.
  3. User B goes to a shared workspace (possible sharing modes are “confidential”, “collaborative”, “public”, and “common”), and enters another “México” address.
    In this situation DMX can’t share user A’s “México” Country topic as user B has no READ permission for it. DMX will create another México topic then.

Note: while user B only sees one México topic (the one she created), user A sees both México topics (e.g. in an auto-suggest menu) as user B’s one is readable as well.

This is expected behavior. Due to access control DMX can no other than creating the “México” Country topic another time.

@gev can you confirm you have created the Country topics with different user accounts? Hint: You can tell a topic/assoc’s owner in the Detail Panel’s “Meta” tab.

The solution to this problem would be not technical but organizational: if a group plan to collaborate/share one would not make things private in the first place.

Another hint: a topic/association can be moved to another workspace after creation, thus e.g. the owner of a topic/assoc can transfer it from a private workspace to a shared workspace. For changing a topic/assoc’s workspace assignment use the Detail Panel’s “Meta” tab.

Hi @jri, I created the duplicate country only as one user. But what you mentioned has very good logic.

It took me a while to figured out how I duplicated the country, it turned out more simple than I though.
As you point out, the semantic is right, but to create several countries or any value you only have to add a blank space at the end of the word. Assuming for this example that the underscore is the blank space, you can create México, México_, México__, México___, as many times as you want but this only happen in the input field, once that you save the information, the workspace and the selection list shows the country without the blank spaces. And you can also do it at the beginning: __México or in the middle, for example New____Zealand. Even though the countries have the same name the only exist once because the blank space is recognised in the string. In the attached image I also did it for the zip code.

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Also, i can create México and Mexico, and the country is duplicate, if you edit only the country as you mentioned the associations are rearrange, but if you type in the value in the input field when creating a new topic with address, it will appears twice.

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Modeling hint: to equip a “buceo” with a geo coordinate you would just create one Composition Definition between “buceo” (parent type) and composite type “Geo Coordinate” (child type). You don’t have to create a new association type. (Hint: the DMX concept Custom Association Type is not relevant here.) Tell me if you have any question.

Indeed a DMX geo-map is not bound to Addresses in the first place, but to sole Geo Coordinates. If you have an Address DMX will determine its geo coordinate automatically (by the means of the OpenStreetMap geocoder). However if you have a (manually entered) geo coordinate, DMX will visualize it on a geo-map as well, just as you describe.

You can type in the coordinates in the format but the input field does not accept decimals. Even though you can entry the values and render the coords in the map, the field input has a red border indicating an error.

The red borders are a Firefox specialty. They do not appear in Chrome or Safari. Firefox regards the input in a <input type="number"> field as invalid if it contains a decimal point. Some people regard this a bug in Firefox (see this debate). The only way to avoid the red border is to specify a step attribute with a decimal value, e.g. 0.1 or 0.000001. However there is no single one-fits-all step value, and (at the moment) the DMX meta model does not have a “resolution” information for individual Number fields. So from my perspective there’s not much we can do at the moment about the red borders, except ignoring them. They are not a real problem, as you’ve said.

Thank you for the hint anyways!

@gev Confirmed! This is a bug.
I’ve filed an issue:
It will be fixed in DMX 5.1.

Thank you very much for investigation and accurate reporting!

Thanks to you, I’m happy to contribute