XML Canonicalization: as an option, allow parsing eol's into the document model (as PCDATA holding those)

[omascia]

Facing the need to implement XML Canonicalization (for XML Signature validation and building), I cannot easily reuse pugixml for the basic steps because the parser seems to always remove eol, unless from identified PCDATA contents when parse_ws_pcdata has been set.

<doc>
<sub>
text
</sub>
</doc>

I can't find a way to keep the eol / whitespace between <doc> and <sub> for instance. Though parse_ws_pcdata do keep the eols within <sub></sub>.
When traversing the tree resulting from such an eol supporting parse, I would expect to see a PCDATA node as first child of <doc> before its sibling child element <sub>. That would allow me to adjust whatever eol might be in there in order to keep only one, which is one of the transformations steps I need to apply before output of the canonicalized text.
To overcome any unwanted behavior when outputting canonicalized content, I can write my own output code from the tree traversal, albeit with the lost eol as a beginning, it is getting nowhere.

[zeux]

Maybe I'm missing something, but parse_ws_pcdata is exactly what you need here.

Quick example:

#include "pugixml.hpp"

#include <stdio.h>

void display(pugi::xml_node node, int depth = 0)
{
        for (int i = 0; i < depth; ++i)
                printf(".");

        if (node.type() == pugi::node_element)
        {
                printf("element %s", node.name());
        }
        else if (node.type() == pugi::node_pcdata)
        {
                printf("pcdata ");

                for (const char* str = node.value(); *str; ++str)
                        printf("0x%02X ", (unsigned char)*str);
        }

        printf("\n");

        for (pugi::xml_node child : node.children())
                display(child, depth + 1);
}

int main()
{
        const char* xml = R"(
<doc>
<sub>
text
</sub>
</doc>
)";

        pugi::xml_document doc;
        pugi::xml_parse_result res = doc.load_string(xml, pugi::parse_default | pugi::parse_ws_pcdata);

        printf("%s\n", res.description());
        display(doc);
}

Output:

No error

.element doc
..pcdata 0x0A 
..element sub
...pcdata 0x0A 0x74 0x65 0x78 0x74 0x0A 
..pcdata 0x0A 

As you can see, doc has three children, two of them are PCDATA with a single newline.

[omascia]

You're right! :)
I was mislead with my real test which had PI too. Looks like there are no PCDATA kept in between PI and elements or between multiple successive PIs. I will re-assemble a more complete and real-life sample and build from there. Anyway, I overlooked the side issue that I will not be able to control whitespace like eol around closing tags. The whole idea of relying on a DOM parser to modify the content (namespace updates and attributes sorting) and then output the required canonicalized form, is probably wrong.
This issue should be closed I think.
Thank you Arseny.