Vvidget Server ► Common Keys ► General
This section explains keys that are common to all, or at least most, dictionaries.
The following table defines the basic input string key and value pairs.
| Nonrecursive Entries | |
| Key | Value Description |
| pvs_version | 1 for the current PVS URL format. |
| image_maker | Usually the string "chart", but can be other things for a custom peer visual server. |
| image_width | The width of the image in pixels. |
| image_height | The height of the image in pixels. |
| image_output_type | Defines the output type. 1 for PNG, 2 for JPEG, 3 for GIF, 1005 for PDF, 1006 for SVG. |
| image_contact | An arbitrary string that represents the sender's identification. |
| string_encoding_type | If 0 then normal character escaped processing is performed on dictionary values. 0 is the default. If 1 then forms based escaped processing is performed where a + is the encoding for a blank. You usually do not have to encode values as web browsers will do it automatically. But, if you are forming a URL for insertion into HTML directly then you should use the escaped encoding for applicable characters. |
The following defines recursive keys. These keys redirect the PVS URL encoding to other places which contain new PVS URL encodings.
| Recursive Entries | |
| Key | Value Description |
| input_string_path | Redirects the dictionary processing to a file on the server. Dictionary entries in that file are added to the total input string. Keys in the original query input string that are also in the file are overwritten. This entry can be used for many different things, but especially to store arbitrary information in a data file. See Input String File for an example. |
| input_string_url | Redirects the dictionary processing to a URL that returns the input string as Content-type: text/plain. Dictionary entries in that returned text are added to the total input string. Keys in the original query input string that are also in the returned text are overwritten. This entry can be used for many different things, but especially to store arbitrary information in a URL. Note that when the URL points to a CGI then the CGI is executed and, hence, the input string becomes programmable and dynamic. See Input String URL for an example. |
The following defines redirection keys. Redirection keys are those which forward the PVS URL to another location based on their values, usually a server running on the same or different computer.
| Redirection Entries | |
| Key | Value Description |
| pvs_ip | Redirects (forwards) the URL to the host at the IP address defined by the value associated with this key. See Direct URL for an example. |
| pvs_channel | Either 0 or 1 for the channel number of the peer visual server running on the localhost or the host pointed to by the pvs_ip value. See Direct URL for an example. |