Add support for a logo for a template

[dselman]

It would be very useful for display purposes if a Cicero template could contain an optional logo.

• File is called: logo.png and is in the root of the template
• Must be a PNG file
• Maximum size is 256x256 pixels

[gagandeepp]

@dselman @mttrbrts is this still open,I can have a look into this?

[mttrbrts]

Thanks @gagandeepp, yes, I'll release the assignment!

[gagandeepp]

how to test this functionality?? @mttrbrts

[gagandeepp]

Any updates?

[jolanglinais]

@mttrbrts pinging you again on this one.

[algomaster99]

@jeromesimeon I would like to give this a try. :)

[jeromesimeon]

There hasn't been any progress on this. It's yours @algomaster99 !

[jeromesimeon]

What should the proper internal representation for an image in the template or metadata class?

I am suspecting it shouldn't be a string. Should it be instead:

• a buffer object?
• a Blob object?
• an Image object? https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Using_images

If we need manipulation of the image (or even simply know the image size) do we need support for a library. e.g., https://github.com/lovell/sharp ?

[jeromesimeon]

Another open question: should the logo file be part of the hash calculated for the template?

[jeromesimeon]

@Michael-Grover is there a logo for Accord Project templates that you would like? (Probably should be added to the templates in the library once the functionality is in place).

Would the 256x256 proposed size be right (e.g., if we want to use it on the template library Web site somewhere, or in the template library component in Cicero UI)?

[algomaster99]

@jeromesimeon

Another open question: should the logo file be part of the hash calculated for the template?

Can you tell me why do we calculate hash? 😅

[jeromesimeon]

@jeromesimeon

Another open question: should the logo file be part of the hash calculated for the template?

Can you tell me why do we calculate hash? 😅

It's a way to uniquely identify the content of the template (can be used to do sanity checks on downloads for example).

[Michael-Grover]

@Michael-Grover is there a logo for Accord Project templates that you would like? (Probably should be added to the templates in the library once the functionality is in place).

Would the 256x256 proposed size be right (e.g., if we want to use it on the template library Web site somewhere, or in the template library component in Cicero UI)?

@jeromesimeon how's this?

256x256 seems really big. What applications might we use for the logo that are 256 x 256, or 128 x 128 on a retina screen?

[jeromesimeon]

Summary of some fact-finding for png files size.

How to determine that the file is PNG:

• Specification: http://www.libpng.org/pub/png/spec/1.2/PNG-Rationale.html#R.PNG-file-signature
• Sample code: https://github.com/arian/pngjs/blob/c1a2f5852686a22229f5f3154f974011162b5263/PNGReader.js#L80

How to determine the size:

• image-size support "fried png" but I don't think we have to. See: http://www.jongware.com/pngdefry.html
• If we don't support fried pngs, this bit of code seems to work:

const fs = require('fs');
const logoBuffer = fs.readFileSync('logo.png');

function calculate(buffer) {
    return {
        height: buffer.readUInt32BE(20),
        width: buffer.readUInt32BE(16)
    }
}

console.log(JSON.stringify(calculate(logoBuffer)));

On this logo:

Trace:

bash-3.2$ node test.js 
{"height":128,"width":128}

[jeromesimeon]

Fixed by @algomaster99 and merged in #533 with some additional fixes in #535

Thanks for the contribution!