src/swipl-devel/packages/xpce/man/refmanual/md/resource.md

In rswipl: Embed 'SWI'-'Prolog'

class resource {#class-resource}

Class resource forms and interface to access data needed to get a running application that is not easily expressed in the programs source-code. Examples are graphics file, help-files, etc.

The following example declares and uses a resource object to access the bitmap 'pce.bm' from the standard bitmap library:

resource(pce, image, image('pce.bm')).

    ...
    new(I, image(resource(pce, image))),
    ...

The resource/3 clause is used by the runtime-generation system to attach the image to the runtime executable. Class resource is used by image ->load to access the resource-data, forming the proper image object.

Instance variables {#class-resource-instvars}

• resource<->class: [name] Class of the resource (@default: don't care). Resource classes are intended to separate the resource name-space into multiple name-spaces dealing with objects of the same type. Resource-data for image objects is generally deneoted with class image. See also <-context.

• resource<-context: any Inherits description from*: message-context

• resource<->name: name Name of the resource. The resource-name is obligatory. See also <-class .and <-context.

Send methods {#class-resource-send}

• resource->access: mode={read,write,append,execute} Test if resource has access. Succeeds if mode equals read, and ->exists succeeds. See also file->access.

• resource->exists Test if resource exists. See also ->access.

• resource->initialise: name=name, class=[name] Create a resource object from its <-name and <-class.

Get methods {#class-resource-get}

• resource<-convert: name=name -> resource Convert name into named resource. See also source_sink<-convert.

rswipl documentation built on June 16, 2026, 5:07 p.m.