[Pas2js] Error Picture.Data Access Violation

[Michael Van Canneyt]

On Sat, 18 Aug 2018, warleyalex via Pas2js wrote:

> TWebImageControl can display an image on the Lazarus form. TWebImageControl
> is similar to a LCL TImage.
>
> TImage is written using DefineProperties, i.e. it needs TReader and a binary
> stream to read. The pas2js classes units don't have a TStream mechanism to
> read files like Lazarus. The serialization LFM to PAS we have an output like
> this:
>
>  with WebImageControl1 do begin
>    Name:='WebImageControl1';
>    Parent:=Self;
>    Left:=160;
>    Height:=16;
>    Top:=104;
>    Width:=16;
>    ExecCustomCSP(Picture,[ { data of the Picture.png here is packed } ]);
>  end;
>
> So, this needs a replacement. Instead of "ExecCustomCSP" the serialization
> should emit something like:
> Picture.LoadFromFile('Picture.png');
>>
> The issue is no record is kept of where the image originated. You'd need to
> track them. You'd typically use a variable at the same scope at the image
> control to store the filename. So, the TWebImageControl have the URL
> property, I can use this property to store the path/filename of the image
> like this:
> ------------------------------------------------------------------
> But at design time, I can not re-open the project,  have to remove the
> Picture.Data so, it can not display an image on the form.
>
> Any idea?

Your whole mechanism seems farfetched to me.

Why don't you use the data url ?
https://stackoverflow.com/questions/16449445/how-can-i-set-image-source-with-base64

That way you can just write the data to the lfm as a base64 string.

You should IMHO provide the user with 2 mechanisms:
1. an URL
2. The above data mechanism.
And not force the user to use 1 mechanism.

The user can pick whatever he thinks is best. The code can then load the image at
run and design time, depending on the property that was used..

Michael.