Default namespaces make rules unintuitive and complex

[ghost]

Just got an email from a user trying to parse an Atom feed (http://feeds.feedburner.com/blogspot/hsDu?format=xml) and not getting any results for entry titles with the rule "/feed/entry/title".

Upon further investigation it looks like that feed defines "http://www.w3.org/2005/Atom" as a default namespace (xmlns arg in the root), which requires the rule actually becomes:
/[http://www.w3.org/2005/Atom]feed/[http://www.w3.org/2005/Atom]entry/[http://www.w3.org/2005/Atom]title

because all the default entries are technically defined in that namespace.

It would be nice if there was a way (either through automatic detection inside the parser) or through an explicit property that could be set to tell the parser to ignore the default namespace and treat it as a no-namespace so when the current path is stored inside the parser, no namespace is appended when it equals the default and then rules like "/feed/entry/title" would work without issue.

Might be worth considering to make this property turned on by default.

Only issue I can think of with that is that all existing literally-correct rules that are written like the one above would all start suddenly failing and would probably drive the authors nuts since they are technically correct-er-er with their pedantic rule definition.

Need to think about this more.

[JakeWharton]

If an implementer upgrades their application with a new version of the library that supports this without first either reading the change log or performing some form of testing then it is their own fault.

I think this would be a very welcome change both for new users looking to use the library and for more-advanced users looking to save time by always including the proper namespace everywhere.

[ghost]

Jake, I appreciate the feedback. In my gut I wanted to make this the new default (because it's easier/nicer) but was worried about the edge use-case. As you pointed out, there are ways to effectively minimize the risk.

I think adoption is limited enough at this point that changing default library behavior should hopefully not be a breaking change for many folks. I'll make plenty of notifications available (notes, blog, etc.) clarifying the new behavior when it goes live.

I'll also do a major version change as is my policy with "API-breaking-changes" to indicate a big change so folks are more tempted to test before rolling to production.

[ghost]

Another user reported the same issue today, with the example file below, the default navPoint rule looks fairly hellacious
/[http://www.daisy.org/z3986/2005/ncx/]ncx/[http://www.daisy.org/z3986/2005/ncx/]navMap/[http://www.daisy.org/z3986/2005/ncx/]navPoint

<?xml version="1.0" encoding="utf-8"?>
<ncx xmlns="http://www.daisy.org/z3986/2005/ncx/" version="2005-1"
    xml:lang="zh_CN">
    <navMap>
        <navPoint id="ncx_newwzh_htmlfile_split_0" playOrder="1">
            <navLabel>
                <text>楔 子</text>
            </navLabel>
            <content src="newwzh_htmlfile_split_0.html" />
        </navPoint>
        <navPoint id="ncx_newwzh_htmlfile_split_1" playOrder="2">
            <navLabel>
                <text>第一章 突击结婚</text>
            </navLabel>
            <content src="newwzh_htmlfile_split_1.html" />
            <navPoint id="ncx_newwzh_htmlfile_split_2" playOrder="3">
                <navLabel>
                    <text>一 知心搭档</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_2.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_3" playOrder="4">
                <navLabel>
                    <text>二 现场“选秀”</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_3.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_4" playOrder="5">
                <navLabel>
                    <text>三 申请结婚</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_4.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_5" playOrder="6">
                <navLabel>
                    <text>四 组织谈话</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_5.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_6" playOrder="7">
                <navLabel>
                    <text>五 首长相亲</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_6.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_7" playOrder="8">
                <navLabel>
                    <text>六 战前婚礼</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_7.html" />
            </navPoint>
        </navPoint>
        <navPoint id="ncx_newwzh_htmlfile_split_8" playOrder="9">
            <navLabel>
                <text>第二章 祸起萧墙</text>
            </navLabel>
            <content src="newwzh_htmlfile_split_8.html" />
            <navPoint id="ncx_newwzh_htmlfile_split_9" playOrder="10">
                <navLabel>
                    <text>一 严家小院</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_9.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_10" playOrder="11">
                <navLabel>
                    <text>二 坑道圆房</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_10.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_11" playOrder="12">
                <navLabel>
                    <text>三 畸形之恋</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_11.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_12" playOrder="13">
                <navLabel>
                    <text>四 红杏出墙</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_12.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_13" playOrder="14">
                <navLabel>
                    <text>五 探亲疑虑</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_13.html" />
            </navPoint>
            <navPoint id="ncx_newwzh_htmlfile_split_14" playOrder="15">
                <navLabel>
                    <text>六 被迫离婚</text>
                </navLabel>
                <content src="newwzh_htmlfile_split_14.html" />
            </navPoint>
        </navPoint>
    </navMap>
</ncx>