![parse しよう
例えばPHP
$jset = json_decode($json);
↓
echo $jset[ search_metadata ][ count ];
↓
10
12](https://image.slidesharecdn.com/parser-131108193845-phpapp01/85/Knct-SG-1-Parser-12-320.jpg)
Knct-SG #1 Parser入門
- 4. ？？？ 4
- 6. 使用例 ? Twitter Client ( json parserが入ってる ) ? Web Browser ( HTML parserが入ってる ) ? etc... 6
- 8. json ? json( JavaScript Object Notation ) ? JavaScriptにおけるオブジェクトの表記法を ベースとした軽量なデータ記述言語 8
- 9. jsonを見てみよう 9
- 10. 10
- 11. parseする #とは 11
- 12. parse しよう 例えばPHP $jset = json_decode($json); ↓ echo $jset[ search_metadata ][ count ]; ↓ 10 12
- 13. 13
- 15. Parserの種類 ? DOM (Document Object Model) API ? SAX (Simple API for XML) 15
- 16. DOM API ? Document Object Model をつくる ? さっきのやつ ? 全体をparseして、あとから要素にaccessする ? 全体のツリー構造を作るのでメモリを食う ? 複雑な動作を実行しやすい 16
- 17. SAX ? Simple API for XML ? 最初から順番にparseし、? 要素を見つけるたびに処理を行う ? 省メモリ ? 複雑な操作を実行しにくい 17
- 18. 代表的なparser実装 ? HTML,XML Parser libxml2 (C言語で実装) ? 色々な言語の標準ライブラリに既に実装済 ? JavaScript JSON.parse() ? PHP json_decode() ? etc... 18
- 19. parserでできること 19
- 20. parserでできること ? 要素を書き出し? libxml2ならxmlSaveFormatFile()とかでできる ? ? DOMツリーを書き換えて、? 元のXMLに上書き保存 etc... 20
- 22. libxml2 ↓ HTMLをparse ↓ <a href= hoge >foo</a>? のhogeとfooを抜き出す 22
- 23. 動かしてみよう 23
- 24. ? curl www.yahoo.co.jp -o index.html ? gcc getURLbyHTML.c -I/usr/local/opt/ libxml2/include/libxml2 -lxml2 ? ./a.out index.html 24
- 26. libxml/tree.h struct _xmlDoc { void *_private;/* xmlElementType type; char *name; /* struct _xmlNode *children; struct _xmlNode *last; /* struct _xmlNode *parent; /* struct _xmlNode *next; /* struct _xmlNode *prev; /* struct _xmlDoc *doc; /* ! }; application data */ /* XML_DOCUMENT_NODE, must be second ! */ name/filename/URI of the document */ /* the document tree */ last child link */ child->parent link */ next sibling link */ previous sibling link */ autoreference to itself */ /* End of common part */ int compression;/* level of zlib compression */ int standalone; /* standalone document (no external refs) 1 if standalone="yes" 0 if standalone="no" -1 if there is no XML declaration -2 if there is an XML declaration, but no standalone attribute was specified */ struct _xmlDtd *intSubset; /* the document internal subset */ struct _xmlDtd *extSubset; /* the document external subset */ struct _xmlNs *oldNs; /* Global namespace, the old way */ const xmlChar *version; /* the XML version string */ const xmlChar *encoding; /* external initial encoding, if any */ void *ids; /* Hash table for ID attributes if any */ void *refs; /* Hash table for IDREFs attributes if any */ const xmlChar *URL; /* The URI for that document */ int charset; /* encoding of the in-memory content actually an xmlCharEncoding */ struct _xmlDict *dict; /* dict used to allocate names or NULL */ void *psvi; /* for type/PSVI informations */ int parseFlags; /* set of xmlParserOption used to parse the document */ int properties; /* set of xmlDocProperties for this document set at the end of parsing */ 26
- 27. libxml/tree.h typedef struct _xmlNode xmlNode; typedef xmlNode *xmlNodePtr; struct _xmlNode { void *_private; /* application data */ xmlElementType type; /* type number, must be second ! */ const xmlChar *name; /* the name of the node, or the entity */ struct _xmlNode *children; /* parent->childs link */ struct _xmlNode *last; /* last child link */ struct _xmlNode *parent; /* child->parent link */ struct _xmlNode *next; /* next sibling link */ struct _xmlNode *prev; /* previous sibling link */ struct _xmlDoc *doc; /* the containing document */ ! /* End of common part */ xmlNs *ns; /* pointer to the associated namespace */ xmlChar *content; /* the content */ struct _xmlAttr *properties;/* properties list */ xmlNs *nsDef; /* namespace definitions on this node */ void *psvi; /* for type/PSVI informations */ unsigned short line; /* line number */ unsigned short extra; /* extra data for XPath/XSLT */ }; 27
- 28. libxml/xpath.h typedef struct _xmlXPathObject xmlXPathObject; typedef xmlXPathObject *xmlXPathObjectPtr; struct _xmlXPathObject { xmlXPathObjectType type; xmlNodeSetPtr nodesetval; int boolval; double floatval; xmlChar *stringval; void *user; int index; void *user2; int index2; }; 28
- 29. libxml/xpath.h struct _xmlXPathContext { xmlDocPtr doc; xmlNodePtr node; ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! }; /* The current document */ /* The current node */ int nb_variables_unused; int max_variables_unused; xmlHashTablePtr varHash; /* unused (hash table) */ /* unused (hash table) */ /* Hash table of defined variables */ int nb_types; int max_types; xmlXPathTypePtr types; /* number of defined types */ /* max number of types */ /* Array of defined types */ int nb_funcs_unused; int max_funcs_unused; xmlHashTablePtr funcHash; /* unused (hash table) */ /* unused (hash table) */ /* Hash table of defined funcs */ int nb_axis; int max_axis; xmlXPathAxisPtr axis; /* number of defined axis */ /* max number of axis */ /* Array of defined axis */ /* the namespace nodes of the context node */ xmlNsPtr *namespaces; /* Array of namespaces */ int nsNr; /* number of namespace in scope */ void *user; /* function to free */ /* extra variables */ int contextSize; int proximityPosition; /* the context size */ /* the proximity position */ /* extra stuff for XPointer */ int xptr; xmlNodePtr here; xmlNodePtr origin; /* is this an XPointer context? */ /* for here() */ /* for origin() */ /* the set of namespace declarations in scope for the expression */ xmlHashTablePtr nsHash; /* The namespaces hash table */ xmlXPathVariableLookupFunc varLookupFunc;/* variable lookup func */ void *varLookupData; /* variable lookup data */ /* Possibility to link in an extra item */ void *extra; /* needed for XSLT */ /* The function name and URI when calling a function */ const xmlChar *function; const xmlChar *functionURI; /* function lookup function and data */ xmlXPathFuncLookupFunc funcLookupFunc;/* function lookup func */ void *funcLookupData; /* function lookup data */ /* temporary namespace lists kept for walking the namespace axis */ xmlNsPtr *tmpNsList; /* Array of namespaces */ int tmpNsNr; /* number of namespaces in scope */ /* error reporting mechanism */ void *userData; /* user specific data block */ xmlStructuredErrorFunc error; /* the callback in case of errors */ xmlError lastError; /* the last error */ xmlNodePtr debugNode; /* the source node XSLT */ /* dictionary */ xmlDictPtr dict; /* dictionary if any */ int flags; /* flags to control compilation */ /* Cache for reusal of XPath objects */ void *cache; 29
- 30. xmlChar * ? libxml2で用いられる文字 ? typedef char xmlChar ? UTF-8であることを明示的に示すため？ 30
- 32. Knct-SG #2 未定