Multi-Page Support

The default behavior of the PDF writer is to write to a single frame on a single page.

A frame is a rectangle on a page where features are drawn. A feature belongs to one or more frames, and a frame belongs to a single page. There are two sets of format attributes for specifying frame and page properties.

Frame Specification Format Attributes

Attribute Name

Contents

pdf_frame_name

If this attribute is set, it specifies the name of the frame to which the feature belongs.

The other frame specification attributes will apply to this frame. See Named Frames below for more information.

If this attribute is unset, then an unnamed frame will be created. See Unnamed Frames below for more information.

pdf_frame_order

This attribute specifies the order in which the frames are drawn.

Valid values are integers. Frames with higher frame order numbers are drawn above frames with lower order numbers. If this attribute is unset on all features belonging to a given frame, then it will assume the default value of 0.

pdf_frame_rectangle

This attribute determines the position of the frame on the page.

The units are in page units, and the format is identical to the Location of Map on Page writer parameter, including support for negative and percentage values.

If this attribute is unset on all features belonging to a given frame, then it will assume the value of the Location of Map on Page writer parameter.

pdf_frame_fixed_aspect

Determines whether the input features to this frame are scaled by the same factor in x and y, or whether the x and y bounds of the input features are scaled independently to fit the target frame on the page.

pdf_frame_clipping_enabled Determines whether input features are clipped to, or may extend beyond, the page object boundary when rendered. The new default is ‘No’, indicating that the input features are not clipped to the page object boundary.
pdf_world_rectangle

This attributes specifies the extents of the map that will be written to the frame.

The units are in world units, and the format is identical to the Map Extents writer parameter.

If this attribute is unset on all features belonging to a given frame, then it will assume the value of the Map Extents writer parameter.

pdf_page_number

This attributes specifies the page number to which the frame belongs.

This attribute is also used to specify the page specifications for that page number. For unnamed frames, if this attribute is unset, then the attribute is set to the value 1. If this attribute is unset on all features belonging to a given named frame, then it will assume the value of 1.

Page Specification Format Attributes

Attribute Name

Contents

pdf_page_number

This attribute specifies the page number of the page to which the page specifications will apply.

For unnamed frames, if this attribute is unset, then the attribute is set to the value 1, and any page specification attributes that are set on this feature will apply to the first page. If this attribute is unset on all features belonging to a given named frame, then it will assume the value of 1.

For a given feature that does not set this attribute, any page specification attributes that are set on that feature are ignored.

pdf_page_size

This attribute specifies the size of the page.

If this attribute is unset on all features belonging to a given page specification, then the page will assume the page size specified by the last prior page that has a page size specification. If no such page exists (for example, on the first page) then the page size is set to the Page Size writer parameter.

Unnamed Frames

If the pdf_frame_name attribute is not set, then the feature belongs to an unnamed frame. Multiple unknown frames may be created during a translation. Features are assigned to an unnamed frame by first assigning default values to unset frame specification attributes. Then features with identical frame specification attributes are assigned to the same unnamed frame.

Named Frames

A feature can belong to a named frame by setting the pdf_frame_name attribute. There are two rules for determining the frame specification of a named frame. Given any two features belonging to the same frame, if the same frame specification attribute is set on both features, then their values must be identical. If a specific frame specification attribute is unset on all features belonging to a frame at the end of the translation, then the frame will assume the default value for that attribute.

By setting the pdf_no_output format attribute to a non-empty value, frame and page specifications can be specified using dummy features without writing these features onto any page.

Page Specifications

Page specifications are handled similarly to named frames, except that pages are referenced by the pdf_page_number attribute.

Given any two features belonging to the same page specification, if the same page specification attribute is set on both features, then their values must be identical. If a specific page specification attribute is unset on all features belonging to a page specification at the end of the translation, then the page will assume the default value for that attribute.

Drawing Order

The drawing order for the PDF writer is determined by a combination of Format Attributes and Feature Type Format Parameters.

Each row in the following table takes precedence over all of the following rows. Lower rows will only be the deciding factor for features where all of the preceding attributes/parameters have the same value.

Attribute or Parameter

Drawing Order Effect

pdf_page_number

See description. Pages are drawn in increasing page number order, starting from the first page.

pdf_frame_order

See description. Features are drawn in a certain frame, as indicated by the feature’s Frame Specification Format Attributes.

Each frame in a page is drawn in order of its pdf_frame_order value, from most negative to most positive. All features in a frame are drawn before any features in subsequent frames.

Layer Order

See description. Features belong to a certain layer, which is determined the Feature Type of the feature.

When a frame is drawn, features from each layer that overlays the frame are drawn. This does not mean that every feature belonging to the layer is drawn, but rather every feature in that frame is drawn layer by layer.

Each layer is drawn in order of its Layer Order value, from most negative to most positive. Within each frame, all features in a layer are drawn before any features in subsequent layers.

pdf_feature_order

See description. This attribute specifies a drawing order for features that belong to the same frame and layer. These features will be drawn in order of their pdf_feature_order value, from most negative to most positive.

If more than one feature in the same page, frame and layer has the same pdf_feature_order, then these features will be drawn in an undefined and arbitrary order.