Chart does not load data on first load and logs error when refreshed

[Isaac Mane]

I have a `sfChart` with two series and one axis. It is a line chart that shows trends over a period of time. 

The problem with this chart is that it does not load data on initial load.

The chart shows this on first load

but when filtered by the dates, it loads correct data

Because the chart is refreshed when filters are applied, I decided to refresh the chart on load. 

This makes the chart load data on init, but I get an error in the console.

here is what I'm working with

[Durga Gopalakrishnan]

Hi Isaac,

Greetings from Syncfusion.

We have prepared sample with attached code snippet. Line charts are rendered properly with secondary axis and with assigned datasource at initial rendering itself. Please check with the below screenshot and sample.

Sample : https://www.syncfusion.com/downloads/support/directtrac/general/ze/ChartInitialLoad868675286.zip

Note : You can refresh the chart only when it is loaded. While trying to redraw the chart before it is loaded, then exception will be thrown.

Since we are unaware of exact scenario which replicates an issue, we request you to share the issue reproduced sample or try to replicate an issue in above sample and video reference so that it will be helpful to validate this case further from our end.

Please let us know if you have any other concerns.

Regards,

Durga Gopalakrishnan.

[Durga Gopalakrishnan]

Issac,

When all chart elements are appended into DOM, then chart is in loaded stage. Using Loaded event, you can know chart is loaded. This event will be trigged after chart load. We have attached the sample for your reference.

<SfChart>

    <ChartEvents Loaded="LoadedEvent"></ChartEvents>

</SfChart>

@code {

public void LoadedEvent(LoadedEventArgs args)

    {

        Console.WriteLine("Loaded event triggered");

    }

}

Sample : https://www.syncfusion.com/downloads/support/directtrac/general/ze/LoadedEvt-1692107674.zip

API Reference : https://blazor.syncfusion.com/documentation/chart/events#loaded

Please let us know if you have any concerns.

[Isaac Mane]

Thank you for your reply. 

How many times does the `LoadedEvent` method run? I was thinking of refreshing the chart in the method, but I'm sure this would crash the page because it will not stop running.

I'm not sure why this particular chart is not working as expected, though. All other charts are working perfectly except this one.

From the image i shared, if the  OnInitializedAsync is changed to this:

I will get this error in the console

and I'm not sure exactly what is null.

This is what I have in the LoadChart method. I logged the data to the console to be sure  it has data and it does. What exactly is wrong

[Durga Gopalakrishnan]

Isaac,

We suggest you to call the chart RefreshAsync method only once to refresh the chart at initial rendering. We have attached modified sample for your reference. Please check with the below snippet and sample.

<SfChart @ref="chartObj">

    <ChartEvents Loaded="OnChartLoaded"></ChartEvents>

</SfChart>

@code {

public SfChart? chartObj;

    public bool initial = false;

    public void OnChartLoaded(LoadedEventArgs args)

    {

        if (!initial){

            chartObj?.RefreshAsync();

            initial = true;

        }

    }

}

Sample : https://www.syncfusion.com/downloads/support/directtrac/general/ze/ChartLoaded-1771031540.zip

If you are still facing problem, please try share a simple standalone sample which replicates the reported issue, so that it will be helpful to validate the reported scenario further from our end. Please let us know if you have any other concerns.