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I am making an application and I want to access a lot of weather data.

Now I want to use the SQL View option to let the WMS layer know which timestamp to use and then it shows me all the data from that moment on a map.

Only I want to be able to do this for all the data in my database. I want my end-user to be able to enter the date they want to see. I want them to see a timeslider for that day AND an extra option which lets them type in a date and then that data will be shown in the application.

Is this possible?

(The data is in a PostGIS database, the application is written in HTML, JSON and JavaScript, is working with npm and OpenLayers and running on Tomcat.)

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  • you could use the WMS TIME dimension and avoid using an SQL view altogether
    – Ian Turton
    Commented Dec 6, 2018 at 12:49
  • I am now thinking it might be possible to make a timeslider with the TIME dimension for a day and then with the SQL View the user can select a datetime so that the application will show a timeslider for that day. But does the TIME dimension have an option for a timeslider, because I have not yet found that. I have seen you can access multiple timestamps, but nothing about a slider yet. Do you know anything about that?
    – Trisha
    Commented Dec 6, 2018 at 13:04
  • the capabilities will give you a valid range or list of times that you use to create the timeslider from.
    – Ian Turton
    Commented Dec 6, 2018 at 14:01
  • I have been searching for about the entire day, but I can't seem to find anything about making a good timeslider that helps me. You seem to know how it works, do you maybe know where I can find some good info about it? I have made a time dimension and this works fine in my layer preview when I add &time=.. to my url. But I am just lost in how to make this into a timeslider. Could you give a nudge in the right way? I can't find any good examples either. Nothing to tie the time dimension and a time slider together so to say.
    – Trisha
    Commented Dec 12, 2018 at 15:44
  • github.com/metno/openlayers-timeslider should do what you need
    – Ian Turton
    Commented Dec 12, 2018 at 15:46

1 Answer 1

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You can use dynamic parameters in Geoserver SQL Views to include the user's date/time settings to your database query.

See https://docs.geoserver.org/stable/en/user/data/database/sqlview.html#parameterizing-sql-views or https://geoserver.geo-solutions.it/edu/en/adding_data/add_sqllayers.html ("Creating a parametric SQL view").

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  • Thanks I am trying this now. I have so far made a SQL View and added my own parameter (called chosen_datetime). I have given it a default value, but when I try to change the paramvalue via the URL it does not work. I am not sure what to enter in the 'Validation Regular Expression' when adding the new parameter for the datetime in the SQL View. Maybe I am doing something wrong there? This is the URL I typed in the browser: '....'openlayers&viewparams=chosen_timestamp:2018-10-14T08:00:00Z
    – Trisha
    Commented Dec 6, 2018 at 13:10
  • The error I get is: java.io.IOExceptionInvalid value for parameter chosen_timestamp
    – Trisha
    Commented Dec 6, 2018 at 13:11
  • The Validation Regular Expression defines the pattern the parameter has to pass (important for security reasons). Only for testing purposes you can set it to .* and thereby allow every value.
    – Mesa
    Commented Dec 6, 2018 at 13:32
  • Thanks! I changed it (for testing purposes, will change it again after I read more about it and know the right expression to enter), but still am getting the same error. Is there something wrong about the way I am putting the date in the url? In the view (default value) I did: 2018-10-18 08:00:00, and that worked. I have now tried almost every timestamp format I can think of, but it still won't work.
    – Trisha
    Commented Dec 6, 2018 at 13:52
  • Figured it out. Something was wrong with the SRID-settings. Thanks so much for the help!
    – Trisha
    Commented Dec 6, 2018 at 13:58

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