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| Last Updated: | 2011-05-04 |
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Table of Contents
This section documents the changes that must be made to MapServer applications when migrating from version 5.6.x (or earlier versions) to 6.0 (i.e. backwards incompatibilities), as well as information on some of the new features.
Version 6.0 features an extensive reworking of the expression parsing capabilities. While this adds functionality it also introduces a couple of regressions:
Logical Expressions
Class text expressions are true expressions in 6.0. This allows for fancy formatting of numeric data but also means string operators must be used to concatenate attribute values and string literals.
On the plus side you can now control the number of decimal places, round and even commify the area value for annotion.
See http://mapserver.org/development/rfc/ms-rfc-64.html and http://trac.osgeo.org/mapserver/ticket/3736 for more information.
As the need for more and more control of label drawing increased it became apparent that we couldn’t extend labelObj’s endlessly. In 6.0 we introduce the idea of label styles, that is, a styleObj inside a labelObj. The styles can be used to add accompanying markers or bounding box elements to a label- kinda like annotation layers. The big benefit is that it’s done in one pass. So you can draw complex roadwork and shields all at the same time. Pretty neat huh? Plus you can do attribute binding for any of the styleObj attributes that support it.
As a result the parameters BACKGROUNDCOLOR, BACKGROUNDSHADOWCOLOR, BACKGROUNDSHADOWSIZE are no more. To draw a label “box” in 6.0 you’d do:
LABEL
...
STYLE # a shadow
GEOMTRANSFORM 'labelpoly'
COLOR 222 222 222
OFFSET 2 2
END
STYLE # bbox
GEOMTRANSFORM 'labelpoly'
COLOR 255 255 255
OUTLINECOLOR 0 0 0
END
END
More verbose but much more flexible in the long run.
MS RFC 60: Labeling enhancement: ability to skip ANGLE FOLLOW labels with too much character overlap introduced a new MAXOVERLAPANGLE keyword to filter out ANGLE FOLLOW labels in which characters overlap. This new option is enabled by default in 6.0 with a default value for MAXOVERLAPANGLE of 22.5 degrees.
As per MS RFC 60: Labeling enhancement: ability to skip ANGLE FOLLOW labels with too much character overlap, it is possible to set MAXOVERLAPANGLE to 0 to fall back on pre-6.0 behavior which was to use hardcoded maxoverlapangle = 0.4*MS_PI (40% of 180 degrees = 72 degrees).
The rendering backends for MapServer have been refactored for version 6 to allow us to support all features across all rendering drivers (GD,AGG,PDF,SVG, etc...).
All line styling must now be specified in class STYLEs in the layer definition.
The following parameters/keywords have been moved from SYMBOL to STYLE:
PATTERN POSITION GAP LINECAP LINEJOIN LINEJOINMAXSIZE
The SYMBOL STYLE parameter/keyword was renamed to PATTERN in version 5.
The SYMBOL TYPE cartoline has been removed.
LINECAP triangle is not supported by AGG or Cairo, and is no longer available. The triangle line end effect can be achieved using GEOMTRANSFORM start and end with a (filled) vector triangle symbol and ANGLE AUTO. This will only work for the line ends, and not for dashes.
Runtime subsitution now requires a validation pattern be present before the substitution will take place (this had been optional). This can be done via a layer metadata tag as before or within layer or web VALIDATION blocks. See ticket #3522 for more information.
All of the query map related modes (e.g. NQUERYMAP, ITEMQUERYMAP, etc...) have been removed in favor of using the “qformat” parameter. That parameter takes an output format name or mime/type as a value and uses that to process a set of query results. For example:
...&mode=nquerymap&... would become ...&mode=nquery&qformat=png24&...
All OGC Web Services are now disabled by default. If you want to enable them as they were in MapServer 5.6 and older releases, add the following metadata in the MAP::WEB section:
"ows_enable_request" "*"
See also: http://mapserver.org/development/rfc/ms-rfc-67.html
To avoid confusion only “wcs_*” and “ows_*” prefixed metadata entries are evaluated in OGC WCS services. Previous versions used “wms_*” prefixed entries as fallback which is dropped in version 6.0 in favor of forcing explicit decisions.
We can now escape single and double quotes in strings and logical expressions. Examples:
NAME "RO\"AD" # double quote inside a a double quote delimited string
NAME 'RO\'AD' # single quote inside a a single quote delimited string
FILTER ('[CTY_NAME]' = 'Ita\'sca') # logical expression that contains a single quote
NOTE: The escape character (backslash) will only work if the following character is ”, ‘ or .
For Windows users: if you have a path string delimited by single/double quotes that ends with , you will have to escape the last backslash.
SHAPEPATH "C:\ms4w\shapefiles\"
# should be modified to...
SHAPEPATH "C:\ms4w\shapefiles\\"
PHP 5.2.0 or more recent is required.
PHP/MapScript now uses exceptions for error report. All errors are catchable.
Object properties can be set like all other php object. ie. myObj->myProperty = 10;
NOTE: The set/setProperty methods are still available.
All object constructors throw an exception on failure
Objects can be created with the php “new” operator. ie. $myShape = ms_newShapeObj(MS_SHAPE_LINE); // or $myShape = new shapeObj(MS_SHAPE_LINE);
ms_newSymbolObj() returns the id of the new/existing symbol.
get it with getSymbolObjectById().
Cloneable objects should be cloned with the PHP clone keyword. There is no more clone methods.
Class properties that have been removed
mapObj: imagetype, imagequality, interlace, scale, transparent
classObj: maxscale, minscale
maxscale, minscale, symbolscale, transparency
legendObj: interlace, transparent
scalebarObj: interlace, transparent
symbolObj: gap, stylelength
webObj: minscale, maxscale
Class methods that have been removed
referenceMapObj has new properties: marker, markername, markersize, maxboxsize, minboxsize
shapeFileObj is automatically closed/writed on destroy. (At the end of the script or with an explicit unset())
layerObj->clearProcessing() method now returns void.
mapObj->queryByIndex(): default behavior for the addToQuery parameter was not ok, now it is.
Methods that now return MS_SUCCESS/MS_FAILURE:
symbolObj: setPoints, setPattern
scalebarObj: setImageColor
outputFormatObj: validate
layerObj: setProcessing, addFeature, draw
setWKTProjection, setLayersDrawingOrder
Methods that now return NULL on failure:
Methods that now return an empty array
The layer query result handing has been re-worked (again) to address some issues introduced in the 5.4/5.6 versions. Gone are resultsGetShape and getFeature methods. You should now use a refactored getShape method to access layer shapes. That method takes a resultObj and returns a shapeObj. Typical use would be (in Perl):
$layer->queryByRect($map, $map->{extent}); # layer is still open
for($i=0; $i<$layer->getNumResults(); $i++) {
$shape = $layer->getShape($layer->getResult($i));
print "$i: ". $shape->getValue(1) ."\n";
}
$layer->close();
A resultObj encapsulates the data used to manage a result set.
To access shapes independently of a query use the new resultObj class:
$layer->open(); $shape = $layer->getShape(new mapscript::resultObj(1)); $layer->close();
See http://mapserver.org/development/rfc/ms-rfc-65.html for more information.
The OUTPUTFORMAT parameter validation when reading from the mapfile will now trigger an error on some problems that in the past were silently fixed up. For instance using RGBA IMAGEMODE with JPEG format now triggers an error instead of switching to IMAGEMODE RGB silently.
The default outputformats names, drivers and mimetypes have been significantly reorganized:
This section documents the changes that must be made to MapServer applications when migrating from version 5.4.x (or earlier versions) to 5.6 (i.e. backwards incompatibilities), as well as information on some of the new features.
The axis order in previous versions of the WFS specifications was to always use easting (x or lon ) and northing (y or lat). WFS 1.1 specifies that, depending on the particular SRS, the x axis may or may not be oriented West-to-East, and the y axis may or may not be oriented South-to-North. The WFS portrayal operation shall account for axis order. This affects some of the EPSG codes that were commonly used such as ESPG:4326. The current implementation makes sure that coordinates returned to the server for the GetFeature request reflect the inverse axis orders for EPSG codes between 4000 and 5000.
RFC 36 added support for templated outptformats, but this new feature was not available for WMS GetFeatureInfo ouptut (see ticket #3024). In MapServer 5.6 this has been resolved by implementing lookup of output formats for query templates by mime-type. However this caused a conflict for the text/html mime-type between the actual text/html query templates and the preconfigured imagemap outputformat which also used the text/html mime-type.
In order to resolve this conflict, the mime-type of the imagemap outputformat has been changed to “text/html; driver=imagemap”. This is unlikely to cause much side-effects to existing applications, but the change is documented here just in case.
This section documents the changes that must be made to MapServer applications when migrating from version 5.2. (or earlier versions) to 5.4 (i.e. backwards incompatibilities), as well as information on some of the new features.
Due to some potential security vulnerabilities that were uncovered in previous versions of MapServer, RFC-56 introduced a number of changes to tighten access control on mapfiles and templates and limit the risk of leaking arbitrary file contents. These changes were introduced in version 5.4.0, and were also backported to v5.2.2 and 4.10.4.
The new requirements are as follows:
See also: http://mapserver.org/development/rfc/ms-rfc-56.html
This section documents the changes that must be made to MapServer applications when migrating from version 4.10.x (or earlier versions) to 5.x (i.e. backwards incompatibilities), as well as information on some of the new features.
Attribute Bindings: In an effort to stem the tide of keyword overload and add functionality MapServer 5.0 supports a new method of binding feature attributes to STYLE and LABEL properties. In the past keywords like ANGLEITEM or LABELSIZEITEM were used, now you denote the attribute in the context of the property being bound. For example, to bind an attribute to a label size you’d do:
LABEL
...
SIZE [mySizeItem]
END
The []’s denote a binding (as with logical expressions). The following keywords are no longer supported and their presence will throw an error:
The following properties can accept bindings:
Colors may be given as a hex value (e.g. #FFFFFF) or an RGB triplet (e.g. 255 255 255).
Layer Transparency: The values for the TRANSPARENCY parameter have always been backwards and in an effort to resolve that the parameter has been renamed OPACITY. TRANSPARENCY is still recognized by the mapfile parser but is depricated and should be avoided.
Scale Parameters: MapServer’s handling of scale has long been a source for confusion. The values use in a layer MINSCALE are really the denominators from a representative fraction (e.g. 1:24000). To help clarify this all scale parameters are now end with DENOM. So MINSCALE => MINSCALEDENOM, SYMBOLSCALE => SYMBOLSCALEDENOM, and so on. The mapfile parser still recognizes the older keywords but they are depricated and should be avoided.
Symbol Style: STYLEs are used within a symbol definition to store dash patterns for line symbolization. However, there is potential confusion with the style object that is used within class definitions. To resolve that confusion the symbol STYLE parameter has been renamed PATTERN. The symbol file parser will still recognize the STYLE keyword but it is depricated and should be avoided.
Prior to MapsServer 5.0, if a pixmap symbol was used in style on a Line Layer, the symbol was used as a brush to draw the line. In MapServer 5.0, it is possible to draw the pixmap symbol along the line (Note that this was available using a true type symbol). To achieve this, the user needs to use the parameter GAP with it’s pixmap symbol definition in the symbol file. The GAP represents the distance between the symbols. If the GAP is not given, the pixmap symbol will be used as a brush.
see the AGG rendering specifics for the changes relating to the addition of the Antigrain Geometry rendering engine.
Previous versions of the MapServer CGI program allowed certain parameters to be changed via a URL using a cumbersome syntax such as map_layer_0_class_0_color=255+0+0 which changes the color in one classObj. Not only was this cumbersome for users but also from a code maintenance perspective since we had to maintain seperate loaders for URL-based config and file-based config. RFC-31 attempts to streamline both by migrating to a single object loading function that can be used with strings (either in MapScript or via URL) or with files.
So, in the past you have to change parameters one-at-a-time. Now you can pass chunks of mapfiles (with security restrictions) to the CGI interface. The map_object notation is still necessary to identify which object you want to modify but you can change multiple properties at one time. Note that you can use either a ‘_’ or a ‘.’ to seperate identifiers.
Example 1, changing a scalebar object:
...&map.scalebar=UNITS+MILES+COLOR+121+121+121+SIZE+300+2&...
Example 2, changing a presentation style:
...&map.layer[lakes].class[0].style[0]=SYMBOL+crosshatch+COLOR+151+51+151+SIZE+15&...
Example 3, creating a new feature
...&map_layer[3]=FEATURE+POINTS+500000+1000000+END+TEXT+'A+test+point'+END&...
The variable identifies an object uniquely (by name or index in the case of layerObj’s and classObj’s). The value is a snippet of a mapfile. You cannot create new objects other than inline features at this point.
Attribute queries (qstring) done via the mapserv CGI could theoretically be used for SQL injection.
No exploit has been reported, but in order to mitigate the risk, a new validation pattern mechanism has been added in 5.0.
In the case of qstring attribute queries, the qstring_validation_pattern layer-level metadata is required for qstring queries to work. The metadata value is a regular expression that the qstring value must match otherwise mapserv produces a fatal error. A fatal error is also produced if qstring is used but qstring_validation_pattern is not provided.
Note that similar validation pattern mechanism has been available for %variable% substitutions since version 4.10, but in this case it is optional. The pattern for %myvar% is provided via a metadata called myvar_validation_pattern.
Layer Transparency: The layerObj transparency parameter is now called opacity. Scripts setting that value in code must be updated.
Symbol Style: the symbolObj style parameter is now called pattern. MapScript does not allow direct modification of that parameter. In Swig-based languages the symbolObj method setStyle is now called setPattern. In PHP/MapScript, the methods setStyle and getStyle are now called setPattern and getPattern.
A new msGetVersionInt() function returning the current MapServer version in integer format has been added to facilitate version checks in the future. Given version x.y.z, it returns (x*0x10000 + y*0x100 + z). For instance, for v5.0.0 it will return 0x050000 (note the hexadecimal notation).
Layer Transparency: The layerObj transparency parameter is now called opacity. The old “transparency” name is deprecated and will be removed in a future release. Scripts getting/setting that value in code must be updated.
All occurences of scale, minscale, maxscale, etc... parameters have been deprecated and renamed with a “denom” suffix (e.g. minscale becomes minscaledenom, etc.). The deprecated parameters will be removed in a future release. Scripts getting/setting them must be updated.
SymbolObj style has been renamed pattern. The old “stylelength” parameter and setStyle() and getStyleArray() methods have been deprecated and “patternlength”, setPattern() and getPatternArray() should be used instead. They will be removed in a future release.
layer.getShape(int tileindex, int shapeindex)) has been deprecated and renamed to layer.getFeature(int shapeindex [, int tileindex = -1]) to match the SWIG MapScript equivalent. Note that the order of the arguments is reversed since tileindex is optional in getFeature().
class.getExpression() and layer.getFilter() have been deprecated and renamed to class.getExpressionString() and layer.getFilterString() to match what we have in SWIG MapScript. The String suffix in the function name also more clearly indicates that the return value is not an object but a string representation of it.
A new ms_GetVersionInt() function returning the current MapServer version in integer format has been added to facilitate version checks in the future. Given version x.y.z, it returns (x*0x10000 + y*0x100 + z). For instance, for v5.0.0 it will return 0x050000 (note the hexadecimal notation).
Required Parameters for GetMap and GetFeatureInfo: previously, MapServer did not check for the following parameters when responding to an OGC:WMS GetMap or GetFeatureInfo request:
- SRS
- FORMAT
- WIDTH
- HEIGHT
- STYLES or SLD / SLD_BODY
- BBOX
That is, a GetMap request would process without error if these were not passed by the WMS client.
A compliant OGC:WMS 1.1.0 and 1.1.1 REQUIRES these parameters. This may affect OGC:WMS client requests who were not passing these values. Ticket 1088 fully documents this issue. In addition to WMS compliance, this was also decided that by adding this constraint, if an OGC client request (as described earlier) breaks something, people should fix their client anyway since if they change WMS vendor, they will have problems as well.
“sos_describesensor_url” “http://example.org/sml/%procedure%.xml“
This change has been made to clarify and unify the meaning of procedure within SOS Server’s context of a DescribeSensor request.
MapServer’s main include file has been renamed from “map.h” to “mapserver.h”.
A new mapserver-config script has been created with the following options:
Usage: mapserver-config [OPTIONS]
Options:
[--libs]
[--dep-libs]
[--cflags]
[--defines]
[--includes]
[--version]
The shared and static link libraries for MapSserver have been renamed libmapserver.x.y.so and libmapserver.a respectively.
The –enable-coverage configure option has been renamed to –enable-gcov since the former name led users to think it might be related to enabling support for WCS or Arc/Info coverages:
--enable-gcov Enable source code coverage testing using gcov
Some features present in MapServer are likely to be removed in a future release. Features might be headed for deprecation because:
- they have been replaced by a superior or more capable solution
- they have stopped being maintained
Users of these features should be prepared for these upcoming changes and start adapting their mapfiles in consequence. If you have strong and motivated objections as to the removal of one or more of these features please open a discussion in the usual MapServer communication channels.
Cartoline symbols: these were a hack to overcome GD weaknesses, and their functionality is now supported by the AGG renderer. They have become poorly supported in current MapServer versions. Keywords allowing for setting the style of line joins and caps will be moved to the STYLE block.
RGB/RGBA output with GD: support for RGB and RGBA image types will likely not be maintained anymore. PC256 will continue to be supported with GD, while RGB and RGBA will liekly only be supported with AGG