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 multidimensional 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
40 multidimensional tiedhash using AnyData.pm or via DBI and SQL commands
41 using DBD::AnyData.pm. See those modules for complete details of
42 usage.
43 The module is built on top of Michel Rodriguez's excellent XML::Twig
45 which means that the AnyData interfaces can now include information
46 from DTDs, be smarter about inferring data structure, reduce memory
47 consumption on huge files, and provide access to many powerful features
48 of XML::Twig and XML::Parser on which it is based.
49 Importing options allow you to import/access/modify XML of almost any
51 length or complexity. This includes the ability to access different
52 subtrees as separate or joined databases.
53 Exporting and converting options allow you to take data from almost any
55 source (a perl array, any DBI database, etc.) and output it as an XML
56 file. You can control the formatting of the resulting XML either by
57 supplying a DTD listing things like nesting of tags and which columns
58 should be output as attributes and/or you can use XML::Twig
59 pretty_print settings to generate half a dozen different levels of
60 compactness or whitespace in how the XML looks.
61 The documentation below outlines the special flags that can be used in
63 either of the interfaces to fine-tune how the XML is treated.
64 The flags listed below define the relationship between tags and
66 attributes in the XML document and columns in the resulting database.
67 In many cases, you can simply accept the defaults and the database will
68 be built automatically. However, you can also fine tune the generation
69 of the database by specifying which tags and attributes you are
70 interested in and their relationship with database columns.
71
73 Prerequisites
74 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
87 structure from examining the file or data itself, making use of the DTD
88 if there is one, otherwise scanning the first child of the XML tree for
89 structural information.
90 Optional flags
92 If the default behavior is not sufficient, you may either specify a
93 "record_tag" which will be used to define column names, or you can define an
94 entire tag-to-column mapping.
95 For simple XML, no flags are necessary:
97 <table>
99 <row row_id="1"><name>Joe</name><location>Seattle</location></row>
100 <row row_id="2"><name>Sue</name><location>Portland</location></row>
101 </table>
102 The record_tag will default to the first child, namely "row". The
104 column names will be generated from the attributes of the record tag
105 and all of the tags included under the record tag, so the column names
106 in this example will be "row_id","name","location".
107 If the record_tag is not the first child, you will need to specify it.
109 For example:
110 <db>
112 <table table_id="1">
113 <row row_id="1"><name>Joe</name><location>Seattle</location></row>
114 <row row_id="2"><name>Sue</name><location>Portland</location></row>
115 </table>
116 <table table_id="2">
117 <row row_id="1"><name>Bob</name><location>Boise</location></row>
118 <row row_id="2"><name>Bev</name><location>Billings</location></row>
119 </table>
120 </db>
121 In this case you will need to specify "row" as the record_tag since it
123 is not the first child of the tree. The column names will be generated
124 from the attributes of row's parent (if the parent is not the root),
125 from row's attributes and sub tags, i.e.
126 "table_id","row_id","name","location".
127 In some cases you will need to specify an entire tag-to-column mapping.
129 For example, if you want to use a different name for the database
130 column than is used in the XML (especially if the XML tag is not a
131 valid SQL column name). You'd also need to specify a mapping if there
132 are two tags with the same name in different places in the XML tree.
133 The column mapping is a reference to an array of column definitions. A
135 column definition is either a simple name of a tag, or a hash reference
136 with the key containing the full path of the XML tag and the value
137 containing the desired column name alias.
138 For example:
140 col_map => [ 'part_id', 'part_name', 'availability' ];
142 That will find the first three tags with those names and create the
144 database using the same names for the tags.
145 Or:
147 col_map => [
149 { '/parts/shop/id' => 'shop_id'},
150 { '/parts/shop/part/id' => 'part_id'},
151 { '/parts/shop/part/name' => 'part_name'},
152 ];
153 That would find the three tags referenced on the left and create a
155 database with the three column names referenced on the right.
156 When exporting XML, you can specify a DTD to control the output. For
158 example, if you import a table from CSV or from an Array, you can
159 output as XML and specify which of the columns become tags and which
160 become attributes and also specify the nesting of the tags in your DTD.
161 The XML format parser is built on top of Michel Rodriguez's excellent
163 XML::Twig which is itself based on XML::Parser. Parameters to either
164 of those modules may be passed in the flags for adTie() and the other
165 commands including the "prettyPrint" flag to specify how the output XML
166 is displayed and things like ProtocolEncoding. ProtocolEncoding
167 defaults to 'ISO-8859-1', all other flags keep the defaults of
168 XML::Twig and XML::Parser. See the documentation of those modules for
169 details;
170 CAUTION: Unlike other formats, the XML format does not save changes to
172 the file as they are entered, but only saves the changes when you explicitly
173 request them to be saved with the adExport() command.
174
176 copyright 2000, Jeff Zucker <jeff@vpservices.com> all rights reserved
177perl v5.36.0 2023-01-19 AnyData::Format::XML(3)