Merge Error When 2 different pages are prepend before TOC using pdfAddPageItem pageBeforeTOC=true

[Ritesh Kumar Gupta]

I am trying to add two pages before TOC- say 'title page' and 'disclaimer' page.

The final merged PDF should look like [title, disclaimer, toc, main]

The approach I am taking is:
I am adding {{{pdfAddPageItem pageBeforeTOC=true}}} on both title and disclaimer template which has to appear before toc.

//disclaimer template
<p><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR></p>
{{{pdfAddPageItem pageBeforeTOC=true}}} <p>This is Disclaimer Page</p>

//Title page template
<p><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR></p>
{{{pdfAddPageItem pageBeforeTOC=true}}} <p>This is Title Page</p>

And in toc, I am adding empty pages using helper function:

{{#each (getPagesBeforeTOC @root)}}
    <!-- in order to produce a new page there must be some element before -->
    <div style="visibility: hidden;">&nbsp;</div>
    <div style="page-break-before: always;"></div>
{{/each}}

However, this is crashing:

Error: Error while executing pdf-utils operations. incorrect header check
    at module.exports (/app/node_modules/jsreport-core/lib/util/createError.js:11:13)
    at Reporter.createError (/app/node_modules/jsreport-core/lib/reporter.js:332:12)
    at AsyncFunction.<anonymous> (/app/node_modules/jsreport-pdf-utils/lib/main.js:382:22)
caused by: Error: incorrect header check
    at Zlib.zlibOnError [as onerror] (zlib.js:180:17)
    at processChunkSync (zlib.js:426:12)

Any help is appreciated.

Here is the narrowest version of the replicator:
https://playground.jsreport.net/w/anon/xSDm7AJx

Please note, If I add only one page before TOC, then it works perfectly without any problem. You can check this by disabling any of the title or disclaimer items in the main pdf-utils merge operation.

In most of the use cases, to create any report "multiple pages with the headers footers+page number" are required to prepend before TOC. Hence, I am looking for a robust solution for this, if my approach above is not the correct one.

Thanks.

[jan_blaha]

Thank you for the demo.

The following is the problematic place

{{#each (getPagesBeforeTOC @root)}}
    <!-- in order to produce a new page there must be some element before -->
    <div style="visibility: hidden;">&nbsp;</div>
    <div style="page-break-before: always;"></div>
{{/each}}

Chrome prints completely empty page buffer when applying this HTML. This makes problems to the jsreport-pdf-utils now. You can change it with something like this. It shouldn't make layout difference but makes the pdf merge happy.

{{#each (getPagesBeforeTOC @root)}}
    <!-- in order to produce a new page there must be some element before -->
     <div style="display: inline-block;font-size:1.1px;">&nbsp;</div>
    <div style="page-break-before: always;"></div>
{{/each}}

We will make sure pdf utils can handle also the original code in the next release.

[Ritesh Kumar Gupta]

@jan_blaha : Amazing. It works. I should have posted this query much earlier, spent 2 days in digging out why it's crashing. Thanks again a ton. :)