This adds the possibility for the HTML parser to gather typed items URLs
annotated in HTML tags with itemscope and itemtype attributes (see
microdata specification https://www.w3.org/TR/microdata/ ), notably
Types from the schema.org vocabulary, but also Types/Classes from any
other vocabulary, such as the common ones listed in the RDFa core
context ( https://www.w3.org/2011/rdfa-context/rdfa-1.1.html ).
When a crawl is started, a new field to exclude content from scraping is
available. The field can be identified with the class name of div tags.
All text contained in such a div tag where the configured class name(s)
match are not indexed, while the remaining page is indexed.
Thus enable getpageinfo_p API to return something in a reasonable amount
of time on resources over MegaBytes size range.
Support added first with the generic XML parser, for other formats
regular crawler limits apply as usual.
Recursive processing was removed in commit
67beef657f, but one remained for anchors
content(likely omitted from refactoring). It is no more necessary :
other links such as images embedded in anchors are currently correctly
detected by the parser.
More annoying : that remaining recursive processing could lead to almost
endless processing when encountering some (invalid) HTML structures
involving nested anchors, as detected and reported by lucipher on YaCy
forum ( http://forum.yacy-websuche.de/viewtopic.php?f=23&t=6005 ).
For faster processing (measured about 2 times faster on many real-world
examples) and more advanced detection (previous algorithm detected only
URLs separated from the rest of the text by a space character).
This parser adds support for any XML based format other than already
supported XML vocabularies such XHTML, RSS/Atom feeds... It will
eventually be used as a fallback if one of these specific parsers fail,
before falling back to the existing genericParser which extracts not
that much useful information except URL tokens.
recognized as tag like 1<a
reported in https://github.com/yacy/yacy_search_server/issues/109
Script content is ignored by default, but the text is filtered for html
tags. Modified scraper to skip tag filtering while within a <script>
section (until a closing tag is detected </script>.
Possible side effect, missing </script> end-tag will truncate trailing
content text.
add "datetime" property of <time> tag to scrapers startdate list.
Datetime is parsed as iso8601 (xml) date, html5 allows partial as well
as duration (not handled by this)
Applied strategy : when there is no restriction on domains or
sub-path(s), stack anchor links once discovered by the content scraper
instead of waiting the complete parsing of the file.
This makes it possible to handle a crawling start file with thousands of
links in a reasonable amount of time.
Performance limitation : even if the crawl start faster with a large
file, the content of the parsed file still is fully loaded in memory.
to support the new time parser and search functions in YaCy a high
precision detection of date and time on the day is necessary. That
requires that the time zone of the document content and the time zone of
the user, doing a search, is detected. The time zone of the search
request is done automatically using the browsers time zone offset which
is delivered to the search request automatically and invisible to the
user. The time zone for the content of web pages cannot be detected
automatically and must be an attribute of crawl starts. The advanced
crawl start now provides an input field to set the time zone in minutes
as an offset number. All parsers must get a time zone offset passed, so
this required the change of the parser java api. A lot of other changes
had been made which corrects the wrong handling of dates in YaCy which
was to add a correction based on the time zone of the server. Now no
correction is added and all dates in YaCy are UTC/GMT time zone, a
normalized time zone for all peers.
- date navigation
The date is taken from the CONTENT of the documents / web pages, NOT
from a date submitted in the context of metadata (i.e. http header or
html head form). This makes it possible to search for documents in the
future, i.e. when documents contain event descriptions for future
events.
The date is written to an index field which is now enabled by default.
All documents are scanned for contained date mentions.
To visualize the dates for a specific search results, a histogram
showing the number of documents for each day is displayed. To render
these histograms the morris.js library is used. Morris.js requires also
raphael.js which is now also integrated in YaCy.
The histogram is now also displayed in the index browser by default.
To select a specific range from a search result, the following modifiers
had been introduced:
from:<date>
to:<date>
These modifiers can be used separately (i.e. only 'from' or only 'to')
to describe an open interval or combined to have a closed interval. Both
dates are inclusive. To select a specific single date only, use the
'to:' - modifier.
The histogram shows blue and green lines; the green lines denot weekend
days (saturday and sunday).
Clicking on bars in the histogram has the following reaction:
1st click: add a from:<date> modifier for the date of the bar
2nd click: add a to:<date> modifier for the date of the bar
3rd click: remove from and date modifier and set a on:<date> for the bar
When the on:<date> modifier is used, the histogram shows an unlimited
time period. This makes it possible to click again (4th click) which is
then interpreted as a 1st click again (sets a from modifier).
The display feature is NOT switched on by default; to switch it on use
the /ConfigSearchPage_p.html servlet.
given css class and extends a given vocabulary with a term consisting
with the text content of the html class tag. Additionally, the term is
included into the semantic facet of the document. This allows the
creation of faceted search to documents without the pre-creation of
vocabularies; instead, the vocabulary is created on-the-fly, possibly
for use in other crawls. If any of the term scraping for a specific
vocabulary is successful on a document, this vocabulary is excluded for
auto-annotation on the page.
To use this feature, do the following:
- create a vocabulary on /Vocabulary_p.html (if not existent)
- in /CrawlStartExpert.html you will now see the vocabularies as column
in a table. The second column provides text fields where you can name
the class of html entities where the literal of the corresponding
vocabulary shall be scraped out
- when doing a search, you will see the content of the scraped fields in
a navigation facet for the given vocabulary
attribute in the <a> tag for each crawl. This introduces a lot of
changes because it extends the usage of the AnchorURL Object type which
now also has a different toString method that the underlying
DigestURL.toString. It is therefore not advised to use .toString at all
for urls, just just toNormalform(false) instead.
- some outboundlinks_anchortext_txt in index contain e.g. <span>text</span> or more tags,
remove all tags for text property (inline img tags are still parsed)
- added test case for above (to htmlParserTest)
- fix solr test case
Michael Christen