added text not visible

[nnnikolay]

Hi Gal.

Thanks for your tests in the test folder, using it I was able to modify existing pdf file, but the funny thing is, not every PDF can be modified using the same approach. I've tried to apply the same technic to my files and 90% of them was not modified (I mean, the changes were not visible). Is there a way how to figure out what is the reason for that? Maybe, some z-position instruction required?

P.S. One more thing I've found that HummusJS does not throw any exception if pdf file or font file not found, it would be great if it would do it. is there a way how to get more details (debug log)? because with some pdf files HummusJS does not work at all :(

Best,

[galkahana]

Theres log option. Check the docs. As for modification, itd be good if you know where would be a sensible position to place an element so you can see it. Consider the page dimensions. Try adding true as the last param of pagemodifier constructor

[nnnikolay]

Hi @galkahana

Sorry for such a big delay in the answer, it was quite busy weeks :)

I've tried your recommendations but it does not work for me, maybe I missing something.

Here is the code what I use

var pdfWriter = hummus.createWriterToModify(sourceRoot + '/data/input.pdf', {
    modifiedFilePath: sourceRoot + '/data/output.pdf'
});

var pageModifier = new hummus.PDFPageModifier(pdfWriter,0);

pageModifier.startContext().getContext().writeText(
    'QwErT',
    75, 805,
    {font:pdfWriter.getFontForFile(sourceRoot + '/fonts/arial.ttf'),size:24,colorspace:'gray',color:0x00}
);

pageModifier.endContext().writePage();
pdfWriter.end();

it works with that file input-5.pdf

and does not work with that input.pdf

[nnnikolay]

@galkahana do you have any ideas? Am I doing any mistake in the code?

[galkahana]

you are placing the text outside of the page boundaries. thats why you don't see it.

[nnnikolay]

@galkahana Thanks for your answers, one question in this topic is still left not covered. I was not able to found the answer in WiKi section, why y for writeText is starting from the bottom of the page? I was thinking that 0,0 it's a top left corner, am I wrong in that?

Thanks

[galkahana]

Thats how pdf works. Plain old cartesian coordinate system. Starts from left bottom and goes up and right

[nnnikolay]

@galkahana thanks, I did not know that