Should I use Yahoo-Pipes to scrape the contents of a div?

问题

Given:

• Url - http://www.contoso.com/search.php?q={param} returns:

  -html-
  --body-
  {...}
  ---div id='foo'-
  ----div id='page1'/-
  ----div id='page2'/-
  ----div id='page3'/-
  ----div id='pageN'/-
  ---/div-
  {...}
  --/body-
  -/html-

Wanted:

• The innerHtml of div id='foo' must be fetched by the client (i.e. Javascript).
  • It will be split into discrete items (i.e. div id='page1' to div id='pageN').
• API Throttling prevents server-side code from pre-fetching the data, so the parsing and manipulation burden must be placed on the client.

Question:

• Could Yahoo-Pipes help format the data for easier consumption?
  • The lack of a DOM parser gives me pause.
• Are there any existing pipes that could serve as an example?

回答1:

You can use the YQL module, which allows you to fetch arbitrary URLs and then parse them with XPath. A sample YQL query:

select * from html where url="http://finance.yahoo.com/q?s=yhoo" and
  xpath='//div[@id="yfi_headlines"]/div[2]/ul/li/a'

回答2:

Yes, it's doable with Y! Pipes. You only need two modules from the 'Operators section':

First "Sub Element" to get only the content.

Then just use the "Regex" module to extract the div content and get it through JSON from your site:

Search:

^.*?<div id="foo">(.*?)</div>.*?$

Replace:

$1

来源：https://stackoverflow.com/questions/1095557/should-i-use-yahoo-pipes-to-scrape-the-contents-of-a-div