1AnyData::Format::XML(3)User Contributed Perl DocumentatioAnnyData::Format::XML(3)
2
6 AnyData::Format::XML - tiedhash and DBI access to XML
7
9 # access XML data via a multi-dimensional tied hash
10 # see AnyData.pod for full details
11 #
12 use AnyData;
13 my $table = adTie( 'XML', $file, $mode, $flags );
14 OR
16 # convert data to and from XML
18 # see AnyData.pod for full details
19 #
20 use AnyData;
21 adConvert( 'XML', $file1, $any_other_format, $file2, $flags );
22 adConvert( $any_other_format, $file1, 'XML', $file2, $flags );
23 OR
25 # access the data via DBI and SQL
27 # see DBD::AnyData.pod for full details
28 #
29 use DBI;
30 my $dbh = DBI->connect( 'dbi:AnyData' );
31 $dbh->func('mytable','XML',$file,$flags,'ad_catalog');
32 See below for a description of the optional flags that apply to all of
34 these examples.
35
37 This module allows you to create, search, modify and/or convert XML
38 data and files by treating them as databases without having to actually
39 create separate database files. The data can be accessed via a multi-
40 dimensional tiedhash using AnyData.pm or via DBI and SQL commands using
41 DBD::AnyData.pm. See those modules for complete details of usage.
42 The module is built on top of Michel Rodriguez's excellent XML::Twig
44 which means that the AnyData interfaces can now include information
45 from DTDs, be smarter about inferring data structure, reduce memory
46 consumption on huge files, and provide access to many powerful features
47 of XML::Twig and XML::Parser on which it is based.
48 Importing options allow you to import/access/modify XML of almost any
50 length or complexity. This includes the ability to access different
51 subtrees as separate or joined databases.
52 Exporting and converting options allow you to take data from almost any
54 source (a perl array, any DBI database, etc.) and output it as an XML
55 file. You can control the formating of the resulting XML either by
56 supplying a DTD listing things like nesting of tags and which columns
57 should be output as attributes and/or you can use XML::Twig
58 pretty_print settings to generate half a dozen different levels of com‐
59 pactness or whitespace in how the XML looks.
60 The documentaion below outlines the special flags that can be used in
62 either of the interfaces to fine-tune how the XML is treated.
63 The flags listed below define the relationship between tags and
65 attributes in the XML document and columns in the resulting database.
66 In many cases, you can simply accept the defaults and the database will
67 be built automatically. However, you can also fine tune the generation
68 of the database by specifying which tags and attributes you are inter‐
69 ested in and their relationship with database columns.
70
72 Prerequisites
73 To use the tied hash interface, you will need
75 AnyData
77 XML::Twig
78 XML::Parser
79 To use the DBI/SQL interface, you will need those, and also
81 DBI
83 DBD::AnyData
84 Required flags ( none )
86 If no flags are specified, then the module determines the database
88 structure from examining the file or data itself, making use of the DTD
89 if there is one, otherwise scanning the first child of the XML tree for
90 structural information.
91 Optional flags
93 If the default behavior is not sufficient, you may either specify a
95 "record_tag" which will be used to define column names, or you can define an
96 entire tag-to-column mapping.
97 For simple XML, no flags are necessary:
99 <table>
101 <row row_id="1"><name>Joe</name><location>Seattle</location></row>
102 <row row_id="2"><name>Sue</name><location>Portland</location></row>
103 </table>
104 The record_tag will default to the first child, namely "row". The col‐
106 umn names will be generated from the attributes of the record tag and
107 all of the tags included under the record tag, so the column names in
108 this example will be "row_id","name","location".
109 If the record_tag is not the first child, you will need to specify it.
111 For example:
112 <db>
114 <table table_id="1">
115 <row row_id="1"><name>Joe</name><location>Seattle</location></row>
116 <row row_id="2"><name>Sue</name><location>Portland</location></row>
117 </table>
118 <table table_id="2">
119 <row row_id="1"><name>Bob</name><location>Boise</location></row>
120 <row row_id="2"><name>Bev</name><location>Billings</location></row>
121 </table>
122 </db>
123 In this case you will need to specify "row" as the record_tag since it
125 is not the first child of the tree. The column names will be generated
126 from the attributes of row's parent (if the parent is not the root),
127 from row's attributes and sub tags, i.e. "ta‐
128 ble_id","row_id","name","location".
129 In some cases you will need to specify an entire tag-to-column mapping.
131 For example, if you want to use a different name for the database col‐
132 umn than is used in the XML (especially if the XML tag is not a valid
133 SQL column name). You'd also need to specify a mapping if there are
134 two tags with the same name in different places in the XML tree.
135 The column mapping is a reference to an array of column definitions. A
137 column definition is either a simple name of a tag, or a hash reference
138 with the key containing the full path of the XML tag and the value con‐
139 taining the desired column name alias.
140 For example:
142 col_map => [ 'part_id', 'part_name', 'availability' ];
144 That will find the first three tags with those names and create the
146 database using the same names for the tags.
147 Or:
149 col_map => [
151 { '/parts/shop/id' => 'shop_id'},
152 { '/parts/shop/part/id' => 'part_id'},
153 { '/parts/shop/part/name' => 'part_name'},
154 ];
155 That would find the three tags referenced on the left and create a
157 database with the three column names referenced on the right.
158 When exporting XML, you can specify a DTD to control the output. For
160 example, if you import a table from CSV or from an Array, you can out‐
161 put as XML and specify which of the columns become tags and which
162 become attributes and also specify the nesting of the tags in your DTD.
163 The XML format parser is built on top of Michel Rodriguez's excellent
165 XML::Twig which is itslef based on XML::Parser. Parameters to either
166 of those modules may be passed in the flags for adTie() and the other
167 commands including the "prettyPrint" flag to specify how the output XML
168 is displayed and things like ProtocolEncoding. ProtocolEncoding
169 defaults to 'ISO-8859-1', all other flags keep the defaults of
170 XML::Twig and XML::Parser. See the documentation of those modules for
171 details;
172 CAUTION: Unlike other formats, the XML format does not save changes to
174 the file as they are entered, but only saves the changes when you explicitly
175 request them to be saved with the adExport() command.
176
178 copyright 2000, Jeff Zucker <jeff@vpservices.com> all rights reserved
179perl v5.8.8 2001-07-17 AnyData::Format::XML(3)