transmogrify.htmlcontentextractor-1.0-1.lbn13.noarch

Helpful transmogrifier blueprints to extract text or html out of html content.

transmogrify.htmlcontentextractor.auto ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This blueprint has a clustering algorithm that tries to automatically extract the content from the HTML template. This is slow and not always effective. Often you will need to input your own template extraction rules. In addition to extracting Title, Description and Text of items the blueprint will output the rules it generates to a logger with the same name as the blueprint.

Setting debug mode on templateauto will give you details about the rules it uses. :

  ...
  DEBUG:templateauto:'icft.html' discovered rules by clustering on 'http://...'
  Rules:
        text= html //div[@id = "dal_content"]//div[@class = "content"]//p
        title= text //div[@id = "dal_content"]//div[@class = "content"]//h3
  Text:
        TITLE: ...
        MAIN-10: ...
        MAIN-10: ...
        MAIN-10: ...

Options -------

condition TAL Expression to control use of this blueprint

debug default is ''

transmogrify.htmlcontentextractor ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This blueprint extracts out title, description and body from html either via xpath, TAL or by automatic cluster analysis

Rules are in the form of :

  (title|description|text|anything) = (text|html|optional|tal) Expression

Where expression is either TAL or XPath

For example :

  [template1]
  blueprint = transmogrify.htmlcontentextractor
  title       = text //div[@class='body']//h1[1]
  _delete1    = optional //div[@class='body']//a[@class='headerlink']
  _delete2    = optional //div[contains(@class,'admonition-description')]
  description = text //div[contains(@class,'admonition-description')]//p[@class='last']
  text        = html //div[@class='body']

Note that for a single template e.g. template1, ALL of the XPaths need to match otherwise that template will be skipped and the next template tried. If you'd like to make it so that a single XPath isn't nessary for the template to match then use the keyword `optional` or `optionaltext` instead of `text` or `html` before the XPath.

When an XPath is applied within a single template, the HTML it matches will be removed from the page. Another rule in that same template can't match the same HTML fragment.

If a content part is not useful (e.g. redundant text, title or description) it is a way to effectively remove that HTML from the content.

To help debug your template rules you can set debug mode.

For more information about XPath see

• http://www.w3schools.com/xpath/default.asp - http://blog.browsermob.com/2009/04/test-your-selenium-xpath-easily-with-firebug/

HTMLContentExtractor ====================

This blueprint extracts out fields from html either via xpath rules or by automatic cluster analysis

transmogrify.htmlcontentextractor ---------------------------------

You can define a series of rules which will get applied to the to the _text of the input item. The rules use a XPATH expression or a TAL expression to extract html or text out of the html and adds it as key to the outputted item.

Each option of the blueprint is a rule of the following form :

    (N-)field = (optional)(text|html|delete|optional) xpath

    OR

    (N-)field = (optional)tal tal-expression

"field" is the attribute that will be set with the results of the xpath

"format" is what to do with the results of the xpath. "optional" means the same as "delete" but won't cause the group to not match. if the format is delete or optional then the field name doesn't matter but will still need to be unique

"xpath' is an xpath expression

If the format is tal then instead of an XPath use can use a TAL expression. TAL expression is evaluated on the item object AFTER the XPath expressions have been applied.

For example :

    [template]
    blueprint = transmogrify.htmlcontentextractor
    title = text //div[@class='body']//h1[1]
    _permalink = text //div[@class='body']//a[@class='headerlink']
    _text = html //div[@class='body']
    _label = optional //p[contains(@class,'admonition-title')]
    description = optional //div[contains(@class,'admonition-description')]/p[@class='last']/text()
    _remove_useless_links = optional //div[@id = 'indices-and-tables']
    mimetype = tal string:text/html
    text = tal python:item['_text'].replace('id="blah"','')

You can delete a number of parts of the html by extracting content to fields such as _permalink and _label. These items won't get used be set used to set any properties on the final content so are effective as a means of deleting parts of the html. TAL expressions are evaluated after XPath expressions so we can post process the _text XPath to produce a text stripped of a certain id.

N is the group number. Groups are run in order of group number. If any rule doesn't match (unless its marked optional) then the next group will be tried instead. Group numbers are optional.

Instead of groups you can also chain several blueprints togeather. The blueprint will set _template on the item. If another blueprint finds the _template key in an item it will ignore that item.

The _template field is the remainder of the html once all the content selected by the XPATH expressions have been applied.

transmogrify.htmlcontentextractor.auto -------------------------------------- This blueprint will analyse the html and attempt to discover the rules to extract out the title, description and body of the html.

If the logger output is in DEBUG mode then the XPaths used by the auto extrator will be output to the logger.