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Selectors

The IzPack fileset concept has been adapted from the Apache Ant Selector core type. Their functionality has been shrinked to the needs of IzPack.

Selectors are a mechanism whereby the files that make up a fileset can be selected using more criteria than only a file name provided by the <include> and <exclude> tags.

How to use a Selector

A selector is an element of FileSet, and appears within it. It can also be defined outside of any target by using the <selector> tag and then using it as a reference.

Different selectors have different attributes. Some selectors can contain other selectors, and these are called Selector Containers.

Core Selectors

Core selectors can be used within a fileset and can be contained within Selector Containers.

The core selectors are:

  • <contains> - Select files that contain a particular text string
  • <date> - Select files that have been modified either before or after a particular date and time
  • <depend> - Select files that have been modified more recently than equivalent files elsewhere
  • <depth> - Select files that appear so many directories down in a directory tree
  • <different> - Select files that are different from those elsewhere
  • <filename> - Select files whose name matches a particular pattern. Equivalent to the include and exclude elements of a patternset.
  • <present> - Select files that either do or do not exist in some other location
  • <containsregexp> - Select files that match a regular expression
  • <size> - Select files that are larger or smaller than a particular number of bytes.
  • <type> - Select files that are either regular files or directories.
  • <modified> - Select files if the return value of the configured algorithm is different from that stored in a cache.

Contains Selector

The <contains> tag in a FileSet limits the files defined by that fileset to only those which contain the string specified by the text attribute.

Attribute

Description

Required

text

Specifies the text that every file must contain

Yes

casesensitive

Whether to pay attention to case when looking for the string in the text attribute. Default is true.

No

ignorewhitespace

Whether to eliminate whitespace before checking for the string in the text attribute. Default is false.

No

Here is an example of how to use the Contains Selector:

Selects all the HTML files that contain the string script.

Date Selector

The <date> tag in a FileSet will put a limit on the files specified by the include tag, so that tags whose last modified date does not meet the date limits specified by the selector will not end up being selected.

Attribute

Description

Required

datetime

Specifies the date and time to test for. Should be in the format MM/DD/YYYY HH:MM AM_or_PM, or an alternative pattern specified via the pattern attribute.

At least one of the two.

millis

The number of milliseconds since 1970 that should be tested for. It is usually much easier to use the datetime attribute.

when

Indicates how to interpret the date, whether the files to be selected are those whose last modified times should be before, after, or equal to the specified value. Acceptable values for this attribute are:

  • before - select files whose last modified date is before the indicated date
  • after - select files whose last modified date is after the indicated date
  • equal - select files whose last modified date is this exact date
    The default is equal.

No

granularity

The number of milliseconds leeway to use when comparing file modification times. This is needed because not every file system supports tracking the last modified time to the millisecond level. Default is 0 milliseconds, or 2 seconds on DOS systems.

No

pattern

The SimpleDateFormat-compatible pattern to use when interpreting the datetime attribute. Since Ant 1.6.2

No

checkdirs

Indicates whether or not to check dates on directories.

No, defaults to false

Here is an example of how to use the Date Selector:

Selects all JAR files which were last modified before midnight January 1, 2001.

Depend Selector

The <depend> tag selects files whose last modified date is later than another, equivalent file in another location.

The <depend> tag supports the use of a contained <mapper> element to define the location of the file to be compared against. If no <mapper> element is specified, the identity type mapper is used.

The <depend> selector is case-sensitive.

Attribute

Description

Required

targetdir

The base directory to look for the files to compare against. The precise location depends on a combination of this attribute and the <mapper> element, if any.

Yes

granularity

The number of milliseconds leeway to give before deciding a file is out of date. This is needed because not every file system supports tracking the last modified time to the millisecond level. Default is 0 milliseconds, or 2 seconds on DOS systems.

No

Here is an example of how to use the Depend Selector:

Selects all the Java source files which were modified in the 1.5 release.

Depth Selector

The <depth> tag selects files based on how many directy levels deep they are in relation to the base directory of the fileset.

Attribute

Description

Required

min

The minimum number of directory levels below the base directory that a file must be in order to be selected. Default is no limit.

At least one of the two.

max

The maximum number of directory levels below the base directory that a file can be and still be selected. Default is no limit.

Here is an example of how to use the Depth Selector:

Selects all files in the base directory and one directory below that.

Different Selector

The<different>tag selects files who are deemed to be 'different' from another, equivalent file in another location. The rules for determining difference between two files are as follows:

  1. If there is no 'other' file, it's different.
  2. Files with different lengths are different.
  3. IfignoreFileTimesis turned off, then differing file timestamps will cause files to be regarded as different.
  4. UnlessignoreContentsis set to true, a byte-for-byte check is run against the two files

This is a useful selector to work with programs and tasks that don't handle dependency checking properly; Even if a predecessor task always creates its output files, followup tasks can be driven off copies made with a different selector, so their dependencies are driven on the absolute state of the files, not just a timestamp. For example: anything fetched from a web site, or the output of some program. To reduce the amount of checking, when using this task inside a <copy> task, set the preservelastmodified to propagate the timestamp from source file to destination file.

The <different> tag supports the use of a contained<mapper> element to define the location of the file to be compared against. If no <mapper> element is specified, the identity type mapper is used.

Attribute

Description

Required

targetdir

The base directory to look for the files to compare against. The precise location depends on a combination of this attribute and the <mapper> element, if any.

Yes

ignoreFileTimes

Whether to use file times in the comparison or not. Default is true (time differences are ignored).

No

ignoreContents

Whether to do a byte per byte compare. Default is false (contents are compared). Since ant 1.6.3

No

granularity

The number of milliseconds leeway to give before deciding a file is out of date. This is needed because not every file system supports tracking the last modified time to the millisecond level. Default is 0 milliseconds, or 2 seconds on DOS systems.

No

Here is an example of how to use the Different Selector:

Compares all the Java source files between the 1.4.1 and the 1.5 release and selects those who are different, disregarding file times.

Filename Selector

The <filename> tag acts like the <include> and <exclude> tags within a fileset. By using a selector instead, however, one can combine it with all the other selectors using whatever selector container is desired.

The <filename> selector is case-sensitive.

Attribute

Description

Required

name

The name of files to select. The name parameter can contain standard wildcard characters.

Yes

casesensitive

Whether to pay attention to case when looking at file names. Default is "true".

No

negate

Whether to reverse the effects of this filename selection, therefore emulating an exclude rather than include tag. Default is "false".

No

Here is an example of how to use the Filename Selector:

Selects all the cascading style sheet files.

Present Selector

The <present> tag selects files that have an equivalent file in another directory tree.

The <present> tag supports the use of a contained <mapper> elementto define the location of the file to be tested against. If no <mapper> element is specified, the identity type mapper is used.

The <present> selector is case-sensitive.

Attribute

Description

Required

targetdir

The base directory to look for the files to compare against. The precise location depends on a combination of this attribute and the <mapper> element, if any.

Yes

present

Whether we are requiring that a file is present in the src directory tree only, or in both the src and the target directory tree. Valid values are:

  • srconly - select files only if they are in the src directory tree but not in the target directory tree
  • both - select files only if they are present both in the src and target directory trees
    Default is both. Setting this attribute to "srconly" is equivalent to wrapping the selector in the <not> selector container.

No

Here is an example of how to use the Present Selector:

Selects all the Java source files which are new in the 1.5 release.

Regular Expression Selector

The <containsregexp> tag in a FileSet limits the files defined by that fileset to only those which contain a match to the regular expression specified by the expression attribute.

Attribute

Description

Required

expression

Specifies the regular expression that must match true in every file

Yes

Here is an example of how to use the regular expression Selector:

Selects all the text files that match the regular expression (have a 4,5 or 6 followed by a period and a number from 0 to 9).

Size Selector

The <size> tag in a FileSet will put a limit on the files specified by the include tag, so that tags which do not meet the size limits specified by the selector will not end up being selected.

Attribute

Description

Required

value

The size of the file which should be tested for.

Yes

units

The units that the value attribute is expressed in. When using the standard single letter SI designations, such as "k","M", or "G", multiples of 1000 are used. If you want to use power of 2 units, use the IEC standard: "Ki" for 1024, "Mi" for 1048576, and so on. The default is no units which means the value attribute expresses the exact number of bytes.

No

when

Indicates how to interpret the size, whether the files to be selected should be larger, smaller, or equal to that value. Acceptable values for this attribute are:

  • less - select files less than the indicated size
  • more - select files greater than the indicated size
  • equal - select files this exact size
    The default is less.

No

Here is an example of how to use the Size Selector:

Selects all JAR files that are larger than 4096 bytes.

Type Selector

The <type> tag selects files of a certain type: directory or regular.

Attribute

Description

Required

type

The type of file which should be tested for. Acceptable values are:

  • file - regular files
  • dir - directories

Yes

Here is an example of how to use the Type Selector to select only directories in \${src}:

The Type Selector can be used in conjunction with other selectors. For example, to select files that also exist in a template directory, but avoid selecting empty directories, use:

Selector Containers

To create more complex selections, a variety of selectors that contain other selectors are available for your use. They combine the selections of their child selectors in various ways.

The selector containers are:

  • <and> - select a file only if all the contained selectors select it.
  • <majority> - select a file if a majority of its selectors select it.
  • <none> - select a file only if none of the contained selectors select it.
  • <not> - can contain only one selector, and reverses what it selects and doesn't select.
  • <or> - selects a file if any one of the contained selectors selects it.
  • <selector> - contains only one selector and forwards all requests to it without alteration, provided that any "if" or "unless" conditions are met. This is the selector to use if you want to define a reference. It is usable as an element of <project>. It is also the one to use if you want selection of files to be dependent on Ant property settings.

All selector containers can contain any other selector, including other containers, as an element. Using containers, the selector tags can be arbitrarily deep. Here is a complete list of allowable selector elements within a container:

  • <and>
  • <contains>
  • <custom>
  • <date>
  • <depend>
  • <depth>
  • <filename>
  • <majority>
  • <none>
  • <not>
  • <or>
  • <present>
  • <selector>
  • <size>

And Selector

The <and> tag selects files that are selected by all of the elements it contains. It returns as soon as it finds a selector that does not select the file, so it is not guaranteed to check every selector.

Here is an example of how to use the And Selector:

Selects all the JAR file larger than 4096 bytes which haven't been update since the last millenium.

Majority Selector

The <majority> tag selects files provided that a majority of the contained elements also select it. Ties are dealt with as specified by the allowtie attribute.

Attribute

Description

Required

allowtie

Whether files should be selected if there are an even number of selectors selecting them as are not selecting them. Default is true.

No

Here is an example of how to use the Majority Selector:

Selects all the HTML files which contain at least two of the three phrases "project", "taskdef", and "IntrospectionHelper" (this last phrase must match case exactly).

None Selector

The <none> tag selects files that are not selected by any of the elements it contains. It returns as soon as it finds a selector that selects the file, so it is not guaranteed to check every selector.

Here is an example of how to use the None Selector:

Selects only Java files which do not have equivalent java or class files in the dest directory.

Or Selector

The <or> tag selects files that are selected by any one of the elements it contains. It returns as soon as it finds a selector that selects the file, so it is not guaranteed to check every selector.

Here is an example of how to use the Or Selector:

Selects all the files in the top directory along with all the image files below it.

Not Selector

The <not> tag reverses the meaning of the single selector it contains.

Here is an example of how to use the Not Selector:

Selects all the files in the src directory that do not contain the string "test".

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