![]() ![]() The findAndReplaceWorkspacePath method is intended for replacing part or all of a layer's workspace path. There are two methods on the Layer object that help with this. It is good practice to remove the object reference using the Python del command at the end of a script or within a Python try/except statement.Ĭhanging a layer's data source is a common requirement. The variable that references a layer file on disk will place a lock on the (. Currently, there is no alternative for secured web services. mxd) with the MapDocument function or a layer file with the Layer function, then geodatabase layers will render. If this function is executed prior to opening a map document (. Second, the CreateDatabaseConnection geoprocessing function allows you to create a connection file that is also persisted in memory. First, save the user name and password information with the layers. If it is necessary for these layers to render appropriately, then there are a couple of options. In other words, secured layers will not be rendered in any output. The arcpy.mapping scripting environment will, by default, suppress these dialog boxes during execution, but that means that the layers will be treated as though they have broken data sources. Map documents that contain these layers will prompt the user to enter the appropriate information while the document is opening. Some layers within a map document or layer file may be password protected because the user and password information is not saved within the layer file or map document. If the name value is equal to longName value, then the layer is not a group layer or the layer is not inside a group layer. For example, a layer named Layer1 in a group layer named Group1 will have a longNamevalue of Group1\Layer1. A layer's longName value will include the group name in addition to the layer name. Second, you can evaluate the longNameproperty. First, you can check to see if the layer supports the isGroupLayer property. There are two ways of determining if a layer is a group layer. For example, a map document with a single group layer that contains three sublayers will return a list of four layer names, the group layer being the first and the three sublayers being the second, third, and fourth. The same applies if a group layer is within another group layer. The ListLayers function returns index values that are generated from top to bottom as they appear in the table of contents or the way they appear in a layer (. Group layers and other sublayers (for example, annotation classes) are treated just like ordinary layers. lyr) file that contains the customizations. The UpdateLayer function allows you to replace all layer properties available in the ArcMap Layer Properties dialog box using a layer (. There are many properties available in the ArcMap Layer Properties dialog box that are not exposed to the arcpy scripting environment (for example, display properties, field aliases, selection symbology, and so on). Not all layer properties are accessible through the Layer object. In these cases you may need to test other properties to isolate a layer of interest before doing something to it. There are a few specialized layers and datasets that don't fall into one of these three categories: annotation subclasses, dimension features, network datasets, terrain datasets, topology datasets, and so on. The isFeatureLayer, isGroupLayer, and isRasterLayer properties allow you to identify or isolate the majority of layer types but not all layer types. There are essentially three categories of layers in a map document: feature layers, group layers, and raster layers. The supports method gives you the ability to test if the layer supports a property before trying to get or set its value on a layer type that doesn't support it, therefore reducing the need for additional error trapping. Rather than having to work with different, individual layer objects for all possible layer types and property combinations, a supports method is available to help identify which layer types support which individual layer properties. For example, a feature layer supports a definition query whereas a raster layer does not, but a raster catalog does. There are numerous types of layers and not all of them support the same set of properties. The Layer function, the ListLayers function and the listLegendItemLayers method on the Legend object all provide ways to reference a Layer object. The layer object provides access to many of the common layer properties found in the ArcMap Layer Properties dialog box and it also provides methods for saving layer files. The Layer object is essential for managing layers that reside within a map document (. It can either reference layers in a map document (. ![]() Provides access to layer properties and methods.
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