Difference between revisions of "Parsers"

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This article is part of the [[Getting Started]] Section.
+
This article is part of the [[Advanced User's Guide]]. It presents the available parsers that can be used to import various data sources in BaseX databases. Please visit the [[Serialization]] article if you want to know how to export data.
It presents the available parsers that can be used to import various data sources in BaseX databases.
 
Please visit the [[Serialization]] article if you want to know how to export data.
 
  
 
=XML Parsers=
 
=XML Parsers=
Line 23: Line 21:
 
==XQuery==
 
==XQuery==
  
The [[Database Module#db:add|db:add]] and [[Database Module#db:replace|db:replace]] functions can also be used to add new XML documents to the database. The following example query uses the internal XML parser and adds all files to the database <code>DB</code> that are found in the directory <code>2Bimported</code>:
+
The {{Function|Database|db:add}} and {{Function|Database|db:put}} functions can also be used to add new XML documents to the database. The following example query uses the internal XML parser and adds all files to the database <code>DB</code> that are found in the directory <code>2Bimported</code>:
  
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
for $file in file:list("2Bimported")
 
for $file in file:list("2Bimported")
 
return db:add('DB', $file, '', map { 'intparse': true() })
 
return db:add('DB', $file, '', map { 'intparse': true() })
</syntaxhighlight>
+
</pre>
  
 
=HTML Parser=
 
=HTML Parser=
  
If [http://vrici.lojban.org/~cowan/tagsoup/ TagSoup] is found in the [[Startup#Distributions|classpath]], HTML can be imported in BaseX without any problems. TagSoup ensures that only well-formed HTML arrives at the XML parser (correct opening and closing tags, etc.).
+
If [http://vrici.lojban.org/~cowan/tagsoup/ TagSoup] is found in the [[Startup#Distributions|classpath]], HTML input is converted to well-formed XML documents.
  
If TagSoup is not available on a system, the default XML parser will be used. (Only) if the input is well-formed XML, the import will succeed.
+
If TagSoup is not available on a system, the default XML parser will be used, and the import will only succeed if the input is already well-formed XML (which is usually the case for XHTML documents).
  
 
==Installation==
 
==Installation==
  
====Downloads====
+
===Downloads===
  
 
TagSoup is already included in the full BaseX distributions ({{Code|BaseX.zip}}, {{Code|BaseX.exe}}, etc.). It can also be manually downloaded and embedded on the appropriate platforms.
 
TagSoup is already included in the full BaseX distributions ({{Code|BaseX.zip}}, {{Code|BaseX.exe}}, etc.). It can also be manually downloaded and embedded on the appropriate platforms.
  
====Maven====
+
===Maven===
  
An easy way to add TagSoup to your project is to follow this steps:
+
An easy way to add TagSoup to your project is to as follows:
  
 
1. Visit [https://mvnrepository.com/artifact/org.ccil.cowan.tagsoup/tagsoup/ MVN TagSoup Repository]
 
1. Visit [https://mvnrepository.com/artifact/org.ccil.cowan.tagsoup/tagsoup/ MVN TagSoup Repository]
Line 52: Line 50:
 
3. On the first tab, you can see an XML snippet like this:
 
3. On the first tab, you can see an XML snippet like this:
  
<syntaxhighlight lang="xml">
+
<pre lang="xml">
 
<dependency>
 
<dependency>
 
   <groupId>org.ccil.cowan.tagsoup</groupId>
 
   <groupId>org.ccil.cowan.tagsoup</groupId>
Line 58: Line 56:
 
   <version>1.2.1</version>
 
   <version>1.2.1</version>
 
</dependency>
 
</dependency>
</syntaxhighlight>
+
</pre>
  
4. copy that in your own maven project’s <code>pom.xml</code> file into the <code><dependencies></code> element.  
+
4. Insert the XML fragment into the <code><dependencies></code> element of your project’s <code>pom.xml</code> file.
  
5. don’t forget to run <code>mvn jetty:run</code> again
+
===Debian===
  
====Debian====
+
With Debian, TagSoup will automatically be detected and included after it has been installed via:
 
 
With Debian, TagSoup will be automatically detected and included after it has been installed via:
 
  
 
   apt-get install libtagsoup-java
 
   apt-get install libtagsoup-java
Line 72: Line 68:
 
==Options==
 
==Options==
  
TagSoup offers a variety of options to customize the HTML conversion. For the complete list
+
TagSoup offers a variety of options to customize the HTML conversion. For the complete list, please visit the [http://vrici.lojban.org/~cowan/tagsoup/ TagSoup] website. BaseX supports most options, with a few exceptions:
please visit the [http://vrici.lojban.org/~cowan/XML/tagsoup/#program TagSoup] website. BaseX supports
 
most of these options with a few exceptions:
 
  
 
* '''encoding''': BaseX tries to guess the input encoding, but this can be overwritten by this option.
 
* '''encoding''': BaseX tries to guess the input encoding, but this can be overwritten by this option.
* '''files''': not supported as input documents are piped directly to the XML parser.
+
* '''files''': not supported as the input documents are piped directly to the XML parser.
 
* '''method''': set to 'xml' as default. If this is set to 'html' ending tags may be missing for instance.
 
* '''method''': set to 'xml' as default. If this is set to 'html' ending tags may be missing for instance.
 
* '''version''': dismissed, as TagSoup always falls back to 'version 1.0', no matter what the input is.
 
* '''version''': dismissed, as TagSoup always falls back to 'version 1.0', no matter what the input is.
Line 85: Line 79:
 
* '''reuse''', '''help''': not supported.
 
* '''reuse''', '''help''': not supported.
  
===GUI===
+
==GUI==
  
Go to Menu ''Database'' → ''New'' and select "HTML" in the input format combo box.
+
Go to Menu ''Database'' → ''New'' and select "HTML" in the input format combo box. There's an info in the "Parsing" tab about whether TagSoup is available or not. The same applies to the "Resources" tab in the "Database Properties" dialog.
There's an info in the "Parsing" tab about whether TagSoup is available or not. The
 
same applies to the "Resources" tab in the "Database Properties" dialog.
 
  
These two dialogs come with an input field 'Parameters' where TagSoup options
+
These two dialogs come with an input field 'Parameters' where TagSoup options can be entered. Keys and values are separated by the equal sign, multiple options are separated by commas, e.g.: <code>method=xml,nons=true</code>.
can be entered.
 
  
===Command Line===
+
==Command Line==
  
Turn on the HTML Parser before parsing documents, and set a file filter:
+
Turn on the HTML Parser before parsing documents, set a file filter and optional parsing options:
  
 
   SET {{Option|PARSER}} html
 
   SET {{Option|PARSER}} html
  SET {{Option|HTMLPARSER}} method=xml,nons=true,nocdata=true,nodefaults=true,nobogons=true,nocolons=true,ignorable=true
 
 
   SET {{Option|CREATEFILTER}} *.html
 
   SET {{Option|CREATEFILTER}} *.html
 +
  SET {{Option|HTMLPARSER}} method=xml,nons=true
  
===XQuery===
+
==XQuery==
 
 
The [[HTML Module]] provides a function for converting HTML to XML documents.
 
  
Documents can also be converted by specifying the parser and additional options
+
The [[HTML Module]] provides XQuery functions for converting HTML to XML. In addition, all functions that accept [[Options#Parsing|Parsing Options]] can be used as well to convert HTML:
as function arguments:
 
  
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
fetch:xml("index.html", map {
+
fetch:doc("index.html", map {
 
   'parser': 'html',
 
   'parser': 'html',
   'htmlparser': map { 'html': false(), 'nodefaults': true() }
+
   'htmlparser': map { 'method': 'xml', 'nons': true() }
 
})
 
})
</syntaxhighlight>
+
</pre>
  
 
=JSON Parser=
 
=JSON Parser=
  
BaseX can also import JSON documents. The resulting format is described in the documentation for the XQuery [[JSON Module]]:
+
With BaseX, JSON documents can be imported. The JSON parsing options are described in the documentation of the [[JSON Module]].
  
 
==GUI==
 
==GUI==
  
Go to Menu ''Database'' → ''New'' and select "JSON" in the input format combo box.
+
Go to Menu ''Database'' → ''New'' and select "JSON" in the input format combo box. You can set the following options for parsing JSON documents in the "Parsing" tab.
You can set the following options for parsing JSON documents in the "Parsing" tab:
 
 
 
* '''Encoding''': Choose the appropriate encoding of the JSON file.
 
* '''JsonML''': Activate this option if the incoming file is a JsonML file.
 
  
 
==Command Line==
 
==Command Line==
Line 138: Line 122:
 
==XQuery==
 
==XQuery==
  
The [[JSON Module]] provides functions for converting JSON objects to XML documents.
+
The [[JSON Module]] provides functions for converting JSON to XML.
 +
 
 +
In addition, all functions that accept [[Options#Parsing|Parsing Options]] can be used as well to convert JSON. The following query converts a JSON string to an XML document, using the conversion format {{Code|[[JSON Module#Basic|basic]]}}:
 +
 
 +
<pre lang='xquery'>
 +
db:create('json-db', '{ "key": "value" }', 'example.json', map {
 +
  'parser': 'json',
 +
  'jsonparser': map { 'format': 'basic' }
 +
})
 +
</pre>
  
 
=CSV Parser=
 
=CSV Parser=
  
BaseX can be used to import CSV documents. Different alternatives how to proceed are shown in the following:
+
BaseX can be used to import CSV documents. The CSV parsing options are described in the documentation of the [[CSV Module]].
  
 
==GUI==
 
==GUI==
  
 
Go to Menu ''Database'' → ''New'' and select "CSV" in the input format combo box.
 
Go to Menu ''Database'' → ''New'' and select "CSV" in the input format combo box.
You can set the following options for parsing CSV documents in the "Parsing" tab:
+
You can set the following options for parsing CSV documents in the "Parsing" tab.
 
 
* '''Encoding''': Choose the appropriate encoding of the CSV file.
 
* '''Separator''': Choose the column separator of the CSV file. Possible: <code>comma</code>, <code>semicolon</code>, <code>tab</code> or <code>space</code> or an arbitrary character.
 
* '''Header''': Activate this option if the incoming CSV files have a header line.
 
  
 
==Command Line==
 
==Command Line==
  
Turn on the CSV Parser before parsing documents, and set some optional, parser-specific options and a file filter. Unicode code points can be specified as separators; {{Code|32}} is the code point for spaces:
+
Enable CSV Parsing before parsing documents, and set optional, parser-specific options and a file filter:
  
 
   SET {{Option|PARSER}} csv
 
   SET {{Option|PARSER}} csv
   SET {{Option|CSVPARSER}} encoding=utf-8, lines=true, header=false, separator=space
+
   SET {{Option|CSVPARSER}} encoding=utf-8,header=true,separator=semicolon
 
   SET {{Option|CREATEFILTER}} *.csv
 
   SET {{Option|CREATEFILTER}} *.csv
  
 
==XQuery==
 
==XQuery==
  
The [[CSV Module]] provides a function for converting CSV to XML documents.
+
The [[CSV Module]] provides a function for converting CSV to XML.
  
Documents can also be converted by specifying the parser in an XQuery function.
+
In addition, all functions that accept [[Options#Parsing|Parsing Options]] can be used as well to convert CSV. In the following, all CSV files from a directory are added to a database, with the first line of each file interpreted as column header:
The following example query adds all CSV files that are located in the
 
directory {{Code|2Bimported}} to the database {{Code|DB}} and interprets
 
the first lines as column headers:
 
  
<syntaxhighlight lang="xquery">
+
<pre lang='xquery'>
 
for $file in file:list("2Bimported", false(), "*.csv")
 
for $file in file:list("2Bimported", false(), "*.csv")
return db:add("DB", $file, "", map {
+
return db:add("csv-db", $file, "", map {
 
   'parser': 'csv',
 
   'parser': 'csv',
 
   'csvparser': map { 'header': true() }
 
   'csvparser': map { 'header': true() }
 
})
 
})
</syntaxhighlight>
+
</pre>
  
=Text Parser=
+
=Changelog=
  
Plain text can be imported as well:
+
;Version 11.0
 
+
* Removed: Text Parser
==GUI==
 
 
 
Go to Menu ''Database'' → ''New'' and select "TEXT" in the input format combobox.
 
You can set the following option for parsing text documents in the "Parsing" tab:
 
 
 
* '''Encoding''': Choose the appropriate encoding of the text file.
 
* '''Lines''': Activate this option to create a <code>&lt;line&gt;...&lt;/line&gt;</code> element for each line of the input text file.
 
 
 
==Command Line==
 
 
 
Turn on the CSV Parser before parsing documents and set some optional, parser-specific options and a file filter:
 
 
 
  SET {{Option|PARSER}} text
 
  SET {{Option|TEXTPARSER}} lines=yes
 
  SET {{Option|CREATEFILTER}} *
 
 
 
==XQuery==
 
 
 
Similar to the other formats, the text parser can also be specified via XQuery:
 
 
 
<syntaxhighlight lang="xquery">
 
for $file in file:list("2Bimported", true(), "*.txt")
 
return db:add("DB", $file, "", map { 'parser': 'text' })
 
</syntaxhighlight>
 
 
 
=Changelog=
 
  
 
;Version 7.8
 
;Version 7.8
 
 
* Updated: parser options
 
* Updated: parser options
  
 
;Version 7.7.2
 
;Version 7.7.2
 
 
* Removed: CSV option "format"
 
* Removed: CSV option "format"
  
 
;Version 7.3
 
;Version 7.3
 
 
* Updated: the CSV {{Code|SEPARATOR}} option may now be assigned arbitrary single characters
 
* Updated: the CSV {{Code|SEPARATOR}} option may now be assigned arbitrary single characters
  
 
;Version 7.2
 
;Version 7.2
 
 
* Updated: Enhanced support for TagSoup options
 
* Updated: Enhanced support for TagSoup options

Latest revision as of 17:39, 1 December 2023

This article is part of the Advanced User's Guide. It presents the available parsers that can be used to import various data sources in BaseX databases. Please visit the Serialization article if you want to know how to export data.

XML Parsers[edit]

BaseX provides two alternatives for parsing XML:

  • By default, Java’s SAXParser is used to parse XML documents.
  • The internal, built-in XML parser is more fault-tolerant than Java’s XML parser. It supports standard HTML entities out of the box, and it is faster than the default parser, in particular if small documents are to be parsed. However, the internal parser does not support the full range of DTD features and cannot resolve catalogs.

GUI[edit]

Go to Menu DatabaseNew, then choose the Parsing tab and (de)activate Use internal XML parser. The parsing of DTDs can be turned on/off by selecting the checkbox below.

Command Line[edit]

To turn the internal XML parser and DTD parsing on/off, modify the INTPARSE and DTD options:

 SET INTPARSE true
 SET DTD true

XQuery[edit]

The db:add and db:put functions can also be used to add new XML documents to the database. The following example query uses the internal XML parser and adds all files to the database DB that are found in the directory 2Bimported:

for $file in file:list("2Bimported")
return db:add('DB', $file, '', map { 'intparse': true() })

HTML Parser[edit]

If TagSoup is found in the classpath, HTML input is converted to well-formed XML documents.

If TagSoup is not available on a system, the default XML parser will be used, and the import will only succeed if the input is already well-formed XML (which is usually the case for XHTML documents).

Installation[edit]

Downloads[edit]

TagSoup is already included in the full BaseX distributions (BaseX.zip, BaseX.exe, etc.). It can also be manually downloaded and embedded on the appropriate platforms.

Maven[edit]

An easy way to add TagSoup to your project is to as follows:

1. Visit MVN TagSoup Repository

2. Click on the version you want

3. On the first tab, you can see an XML snippet like this:

<dependency>
  <groupId>org.ccil.cowan.tagsoup</groupId>
  <artifactId>tagsoup</artifactId>
  <version>1.2.1</version>
</dependency>

4. Insert the XML fragment into the <dependencies> element of your project’s pom.xml file.

Debian[edit]

With Debian, TagSoup will automatically be detected and included after it has been installed via:

 apt-get install libtagsoup-java

Options[edit]

TagSoup offers a variety of options to customize the HTML conversion. For the complete list, please visit the TagSoup website. BaseX supports most options, with a few exceptions:

  • encoding: BaseX tries to guess the input encoding, but this can be overwritten by this option.
  • files: not supported as the input documents are piped directly to the XML parser.
  • method: set to 'xml' as default. If this is set to 'html' ending tags may be missing for instance.
  • version: dismissed, as TagSoup always falls back to 'version 1.0', no matter what the input is.
  • standalone: deactivated.
  • pyx, pyxin: not supported as the XML parser can't handle this kind of input.
  • output-encoding: not supported, BaseX already takes care of that.
  • reuse, help: not supported.

GUI[edit]

Go to Menu DatabaseNew and select "HTML" in the input format combo box. There's an info in the "Parsing" tab about whether TagSoup is available or not. The same applies to the "Resources" tab in the "Database Properties" dialog.

These two dialogs come with an input field 'Parameters' where TagSoup options can be entered. Keys and values are separated by the equal sign, multiple options are separated by commas, e.g.: method=xml,nons=true.

Command Line[edit]

Turn on the HTML Parser before parsing documents, set a file filter and optional parsing options:

 SET PARSER html
 SET CREATEFILTER *.html
 SET HTMLPARSER method=xml,nons=true

XQuery[edit]

The HTML Module provides XQuery functions for converting HTML to XML. In addition, all functions that accept Parsing Options can be used as well to convert HTML:

fetch:doc("index.html", map {
  'parser': 'html',
  'htmlparser': map { 'method': 'xml', 'nons': true() }
})

JSON Parser[edit]

With BaseX, JSON documents can be imported. The JSON parsing options are described in the documentation of the JSON Module.

GUI[edit]

Go to Menu DatabaseNew and select "JSON" in the input format combo box. You can set the following options for parsing JSON documents in the "Parsing" tab.

Command Line[edit]

Turn on the JSON Parser before parsing documents, and set some optional, parser-specific options and a file filter:

 SET PARSER json
 SET JSONPARSER encoding=utf-8, jsonml=true
 SET CREATEFILTER *.json

XQuery[edit]

The JSON Module provides functions for converting JSON to XML.

In addition, all functions that accept Parsing Options can be used as well to convert JSON. The following query converts a JSON string to an XML document, using the conversion format basic:

db:create('json-db', '{ "key": "value" }', 'example.json', map {
  'parser': 'json',
  'jsonparser': map { 'format': 'basic' }
})

CSV Parser[edit]

BaseX can be used to import CSV documents. The CSV parsing options are described in the documentation of the CSV Module.

GUI[edit]

Go to Menu DatabaseNew and select "CSV" in the input format combo box. You can set the following options for parsing CSV documents in the "Parsing" tab.

Command Line[edit]

Enable CSV Parsing before parsing documents, and set optional, parser-specific options and a file filter:

 SET PARSER csv
 SET CSVPARSER encoding=utf-8,header=true,separator=semicolon
 SET CREATEFILTER *.csv

XQuery[edit]

The CSV Module provides a function for converting CSV to XML.

In addition, all functions that accept Parsing Options can be used as well to convert CSV. In the following, all CSV files from a directory are added to a database, with the first line of each file interpreted as column header:

for $file in file:list("2Bimported", false(), "*.csv")
return db:add("csv-db", $file, "", map {
  'parser': 'csv',
  'csvparser': map { 'header': true() }
})

Changelog[edit]

Version 11.0
  • Removed: Text Parser
Version 7.8
  • Updated: parser options
Version 7.7.2
  • Removed: CSV option "format"
Version 7.3
  • Updated: the CSV SEPARATOR option may now be assigned arbitrary single characters
Version 7.2
  • Updated: Enhanced support for TagSoup options