1xmerl_xs(3)                Erlang Module Definition                xmerl_xs(3)
2
3
4

NAME

6       xmerl_xs -
7              Erlang has similarities to XSLT since both languages
8            have a functional programming approach.
9

DESCRIPTION

11       Erlang  has similarities to XSLT since both languages have a functional
12       programming approach. Using xmerl_xpath it is possible  to  write  XSLT
13       like transforms in Erlang.
14
15       XSLT  stylesheets  are  often  used when transforming XML documents, to
16       other XML documents or (X)HTML for presentation.  XSLT  contains  quite
17       many  functions  and learning them all may take some effort. This docu‐
18       ment assumes a basic level of understanding of XSLT.
19
20       Since XSLT is based on a functional programming approach  with  pattern
21       matching  and recursion it is possible to write similar style sheets in
22       Erlang. At least for basic transforms. This document describes  how  to
23       use the XPath implementation together with Erlangs pattern matching and
24       a couple of functions to write XSLT like transforms.
25
26       This approach is probably easier for an Erlanger but if you need to use
27       real  XSLT stylesheets in order to "comply to the standard" there is an
28       adapter available to the Sablotron XSLT package which is written i C++.
29       See also the Tutorial.
30

EXPORTS

32       built_in_rules(Fun, E) -> List
33
34              The default fallback behaviour. Template funs should end with:
35              template(E) -> built_in_rules(fun template/1, E).
36
37       select(String::string(), E) -> E
38
39              Extracts the nodes from the xml tree according to XPath.
40
41              See also: value_of/1.
42
43       value_of(E) -> List
44
45              Types:
46
47                 E = term()
48
49              Concatenates all text nodes within the tree.
50
51              Example:
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53
54                <xsl:template match="title">
55                  <div align="center">
56                    <h1><xsl:value-of select="." /></h1>
57                  </div>
58                </xsl:template>
59
60
61              becomes:
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63
64                 template(E = #xmlElement{name='title'}) ->
65                   ["<div align="center"><h1>",
66                     value_of(select(".", E)), "</h1></div>"]
67
68
69       xslapply(Fun::Function, EList::list()) -> List
70
71              Types:
72
73                 Function = () -> list()
74
75              xslapply  is a wrapper to make things look similar to xsl:apply-
76              templates.
77
78              Example, original XSLT:
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80
81                <xsl:template match="doc/title">
82                  <h1>
83                    <xsl:apply-templates/>
84                  </h1>
85                </xsl:template>
86
87
88              becomes in Erlang:
89
90
91                template(E = #xmlElement{ parents=[{'doc',_}|_], name='title'}) ->
92                  ["<h1>",
93                   xslapply(fun template/1, E),
94                   "</h1>"];
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96

AUTHORS

98       <>
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102                                 xmerl 1.3.27                      xmerl_xs(3)