Issue with passing a JSON string to a DMustache helper

edwinsn · 2019-12-19 19:38:35

Hello ab,
The helper being used in this form:

{{{helperA {src: "folder1/file1.jpeg", alt: "some text"}}}}

If I understand the document correctly, this part, the JSON string will be passed to helperA by the engine:

  {src: "folder1/file1.jpeg", alt: "some text"}

is supposed to be passed into the TMyClass.HelperA method below:

The helper function registered with TSynMustache.HelperAdd is defined as something like:
procedure TMyClass.HelperA(const Value: variant; out result: variant);
begin
   // here I expect the "Value" parameter contains the JSON string passed to the helper, 
  // but the Delphi debugger shows that the "Value" parameter is null 
end;

However, the debugger shows that the "Value" parameter is null.

Any hint? Thanks.

Last edited by edwinsn (2019-12-20 03:44:15)

edwinsn · 2019-12-20 09:12:15

I fixed the issue, a github PR is coming

edwinsn · 2019-12-20 09:36:36

@ab,

the gihtub PR is here: https://github.com/synopse/mORMot/pull/260
Please review and make changes as needed. Thanks.

ab · 2019-12-20 12:47:55

It could have been better with some associated regression tests...
I will write them.

edwinsn · 2019-12-20 17:28:19

Thank you ab! I think you can write the tests better, and I'll check them once you are done, so that maybe next time my PR will also include some tests.

ab · 2019-12-23 12:59:31

Your implementation didn't properly handle nested objects and such.
I also added some regression tests.

Please check https://synopse.info/fossil/info/f6cd3f162d

edwinsn · 2019-12-24 11:47:32

Thanks for the new implementation, ab, I actually didn't take into account nested JSON objects.

I tested the new version and found an issue that's also exist with my implementation (which I didn't notice until now).

The issue is with tags with 3 brackets, in that case the result will include an extra unwanted '}' at the end of the rendering result.
I guess the following test can reveal the issue.

  helpers := mustache.HelpersGetStandardList(['jsonhelper'], [MustacheHelper]);
  mustache := TSynMustache.Parse('{{{jsonhelper {a:"a",b:10}}}}');
  html := mustache.RenderJSON('', nil, helpers);
  Check(html='a=a,b=10');

ab · 2019-12-24 18:01:18

You are right.

Please check https://synopse.info/fossil/info/96a87d13b0

edwinsn · 2019-12-25 03:59:41

I confirm it's fixed now! Happy holidays!

mORMot Open Source

#1 2019-12-19 19:38:35

Issue with passing a JSON string to a DMustache helper

#2 2019-12-20 09:12:15

Re: Issue with passing a JSON string to a DMustache helper

#3 2019-12-20 09:36:36

Re: Issue with passing a JSON string to a DMustache helper

#4 2019-12-20 12:47:55

Re: Issue with passing a JSON string to a DMustache helper

#5 2019-12-20 17:28:19

Re: Issue with passing a JSON string to a DMustache helper

#6 2019-12-23 12:59:31

Re: Issue with passing a JSON string to a DMustache helper

#7 2019-12-24 11:47:32

Re: Issue with passing a JSON string to a DMustache helper

#8 2019-12-24 18:01:18

Re: Issue with passing a JSON string to a DMustache helper

#9 2019-12-25 03:59:41

Re: Issue with passing a JSON string to a DMustache helper

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