php|architect's Guide to Web Scraping with PHP - Wind Business ...

Recommendations

Info

104 ” DOM Extension // A slightly more specific way (better if there are multiple lists) if ($list = $doc->getElementById(’thelist’)) { $listItems = $list->getElementsByTagName(’li’); } // Yet another way if the list doesn’t have an id $lists = $doc->getElementsByTagName(’ul’); if ($lists->length) { $list = $lists->item(0); $listItems = $list->getElementsByTagName(’li’); } // Outputs "thelist" (without quotes) echo $list->getAttribute(’id’); // Outputs "Foo" on one line, then "Bar" on another foreach ($listItems as $listItem) { echo $listItem->nodeValue, PHP_EOL; } // Outputs text content inside and echo $list->nodeValue; ?> XPath and DOMXPath Somewhat similar to the way that regular expressions allow instances of character patterns to be found within strings, XPath allows instances of node patterns to be found within XML-compatible documents. Both technologies accomplish their purpose by providing a syntax comprised of meta-characters to express these patterns in a concise and succinct way. With the DOM extension, support for version 1.0 of the XPath standard is implemented as the DOMXPath class. The DOMXPath constructor has a single required parameter: an existing DOMDocument instance on which queries will be performed. DOMXPath has two other relevant methods: evaluate and query. Both accept a string containing an XPath expression with which to query the document as their first parameter. Optionally, a DOMNode instance associated with the document may be passed in as the second parameter ($contextNode) for either method. When specified, that node
DOM Extension ” 105 will become the context node and query results will be restricted to that node and its descendants. Otherwise, the root element of the document is assumed to be the context node. The difference between evaluate and query is that the latter will always return an instance of DOMNodeList whereas the former will attempt to return an appropriately typed result if only one result is found. Absolute Addressing The process of using an XPath expression to obtain a set of nodes to which that expression applies is referred to as addressing. The remainder of the chapter will cover various aspects of addressing and related expression syntax. XPath expressions share several similarities with UNIX filesystem paths, both of which are used to traverse conceptual tree structures. See the example below for specific instances of this. The previous HTML example used to illustrate various concepts of markup languages is reused here to showcase XPath addressing.
Page 1 and 2:
php|architect’s Guide to Web Scra
Page 3:
php|ar chitect’s Guide to W eb Sc
Page 7 and 8:
vi ” CONTENTS Referring URLs . .
Page 9 and 10:
viii ” CONTENTS HTTP Authenticati
Page 11:
x ” CONTENTS Chapter 14 — PCRE
Page 15 and 16:
xiv ” CONTENTS pleted. Each had a
Page 18 and 19:
For ewor d W eb scraping is the fut
Page 21 and 22:
Chapter 1 Introduction If you are l
Page 23 and 24:
Introduction ” 3 in some instance
Page 25:
Introduction ” 5 • Chapters 3-7
Page 28 and 29:
8 ” HTTP R equests The HTTP proto
Page 30 and 31:
10 ” HTTP http://en.wikipedia.org
Page 32 and 33:
12 ” HTTP i Query String Limits M
Page 34 and 35:
14 ” HTTP Server: Apache X-Powere
Page 36 and 37:
16 ” HTTP set, it will persist fo
Page 38 and 39:
18 ” HTTP Content Caching Two met
Page 40 and 41:
20 ” HTTP as 0-499. To specify fr
Page 42 and 43:
22 ” HTTP • Initialize a reques
Page 44:
24 ” HTTP W rap-U p At this point
Page 49 and 50:
HTTP Streams W rapper ” 29 Let
Page 51 and 52:
HTTP Streams W rapper ” 31 Error
Page 53:
HTTP Streams W rapper ” 33 ); ?>
Page 56 and 57:
36 ” cURL Extension Simple R eque
Page 58 and 59:
38 ” cURL Extension Setting M ult
Page 60 and 61:
40 ” cURL Extension • CURLOPT_R
Page 62 and 63:
42 ” cURL Extension containing th
Page 64 and 65:
44 ” cURL Extension operate unpre
Page 66:
46 ” cURL Extension • The sessi
Page 70 and 71:
50 ” pecl_http PECL Extension bal
Page 72 and 73:
52 ” pecl_http PECL Extension •
Page 74 and 75: 54 ” pecl_http PECL Extension Deb
Page 76 and 77: 56 ” pecl_http PECL Extension ass
Page 78 and 79: 58 ” pecl_http PECL Extension );
Page 81 and 82: Chapter 6 P EAR::HTTP_Client The PH
Page 83 and 84: PEAR::HTTP_Client ” 63 • sendRe
Page 85 and 86: PEAR::HTTP_Client ” 65 • By def
Page 87 and 88: PEAR::HTTP_Client ” 67 } ?> $url
Page 89: PEAR::HTTP_Client ” 69 • http:/
Page 92 and 93: 72 ” Zend_Http_Client // Another
Page 94 and 95: 74 ” Zend_Http_Client Configurat
Page 96 and 97: 76 ” Zend_Http_Client getLastResp
Page 98: 78 ” Zend_Http_Client HTTP A uthe
Page 102 and 103: 82 ” Rolling Y o u Own r $stream
Page 104 and 105: 84 ” Rolling Y o u Own r Logic to
Page 106: 86 ” Rolling Y o u Own r See RFC
Page 110 and 111: 90 ” T i d y Extension direct inp
Page 112 and 113: 92 ” T i d y Extension public fun
Page 114 and 115: 94 ” T i d y Extension There are
Page 116: 96 ” T i d y Extension Output Obt
Page 120 and 121: 100 ” DOM Extension T y p of P e
Page 122 and 123: 102 ” DOM Extension ties include
Page 126 and 127: 106 ” DOM Extension // Also retur
Page 128 and 129: 108 ” DOM Extension • //@id add
Page 130: 110 ” DOM Extension • DOM Level
Page 134 and 135: 114 ” SimpleXML Extension The co
Page 136 and 137: 116 ” SimpleXML Extension foreach
Page 138: 118 ” SimpleXML Extension W r a
Page 142 and 143: 122 ” XMLReader Extension Loading
Page 144 and 145: 124 ” XMLReader Extension false o
Page 146 and 147: 126 ” XMLReader Extension cate to
Page 149 and 150: Chapter 13 CSS Selector Libraries T
Page 151 and 152: CSS Selector Libraries ” 131 Abou
Page 153 and 154: CSS Selector Libraries ” 133 •
Page 159 and 160: CSS Selector Libraries ” 139 It
Page 163 and 164: Chapter 14 PCRE Extension There are
Page 165 and 166: PCRE Extension ” 145 Anchors Y o
Page 167 and 168: PCRE Extension ” 147 // Matches
Page 169 and 170: PCRE Extension ” 149 if (preg_mat
Page 171 and 172: PCRE Extension ” 151 The first wa
Page 173 and 174: PCRE Extension ” 153 • T ouse a
Page 177 and 178:
T i p sand T r i c k s Chapter 15 C
Page 179 and 180:
T i p s and T r i c ” k 159 s not
Page 181 and 182:
T i p s and T r i c ” k 161 s W e
Page 185 and 186:
A p p e n d i x A Legality of W e S
Page 187:
Legality of W e b Scraping ” 167
Page 190 and 191:
170 ” M u l t i p r o c e s s i n
show all

php|architect's Guide to Web Scraping with PHP - Wind Business ...

Create successful ePaper yourself

Delete template?

Save as template?