Zoom on TIWChartJS

[lefjucabro]

Hello,

I am a newbie with Intraweb. I used to develop VCL/FMX applications with Delphi.

It's really easy to zoom on charts in these applications.

I downloaded this demo https://github.com/Atozed/IntraWeb/tree/...hi/ChartJS  but I didn't know if it's possible to zoom on a TIWChartJS. If yes, how is it possible ?

Thank you for your advices

[Alexandre Machado]

ChartJS can be zoomed using an external plugin. We are considering adding this plugin to the IWChartJS in the next version.

[lefjucabro]

ChartJS can be zoomed using an external plugin. We are considering adding this plugin to the IWChartJS in the next version.

Thanlks Alexandre for your reply.

Do you means this plugin ? How can I use it with Delphi Alexandria ?

Thanks

[Alexandre Machado]

Yes, zoom has been already made available in IW 15.2.65 that we are releasing today. It's built-in and handled nicely by IW. No need to do anything.

[lefjucabro]

Yes, zoom has been already made available in IW 15.2.65 that we are releasing today. It's built-in and handled nicely by IW. No need to do anything.

Great news Alexandre  ! 

I have to display a serie with 441000 values but I get some slowness issue.

Do you know if I could use TIWChartJS to display that kind of serie ? Do I have to enable/disable some something when adding datas to my serie ?

Thanks for your help

[Alexandre Machado]

There is no way you can expect ChartJS with almost half million values to display instantaneously. It hasn't been designed for it.

https://stackoverflow.com/questions/3181...-js-handle

The data for the series alone will have at least 2 Mb or more, but it can hit 10+ Mb depending on the type of the data, meaning that your page's HTML can be in the order of dozens of Mb. It needs to be generated on server side, compressed, transferred, parsed by the browser, parsed and interpreted by the ChartJS code and then rendered in the canvas.

Out of curiosity, how long does it take to display a chart of this size? The rendering process on IW side is highly optimized using our superfast string builder... It's hard to imagine it being faster than that. Compression is blazing fast. All the other processes are out of IntraWeb's control...

[lefjucabro]

Out of curiosity, how long does it take to display a chart of this size? The rendering process on IW side is highly optimized using our superfast string builder... It's hard to imagine it being faster than that. Compression is blazing fast. All the other processes are out of IntraWeb's control...

Thank you for your reply

It takes about 6 minutes to display chart.

[Alexandre Machado]

it would be interesting (as an exercise) to know where this time is being spent. do you have an idea of the size of the generated HTML? Dev tools (F12) can also tell you how long takes for IW to generate the page and how long it takes on the browser side....

[iwuser]

Yes, zoom has been already made available in IW 15.2.65 that we are releasing today. It's built-in and handled nicely by IW. No need to do anything.

Great news Alexandre  ! 

I have to display a serie with 441000 values but I get some slowness issue.

Do you know if I could use TIWChartJS to display that kind of serie ? Do I have to enable/disable some something when adding datas to my serie ?

Thanks for your help

I'm trying to figure out a way to display thousands of points, without creating the matching number of labels. I.e.: with X axis being time, I'd like to have 24 labels for hours, or 7 labels for days of the week, while having thousands of data points on the chart. How can it be done, it's not clear from the available demo?

[iwuser]

Is anyone using ChartJS? Can anyone help?