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IDL Reference Guide: Network Objects |
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IDLnetOGCWCS objects have the following properties. Properties with the word "Yes" in the "Init" column of the property table can be set via IDLnetOGCWCS::Init.
| Note For a discussion of the property description tables shown below, see About Object Property Descriptions. |
Objects of this class have the following properties.
This property specifies the type of authentication used when connecting to an OGC server. Supported authentication modes are:
When AUTHENTICATION is set, one or both of the USERNAME and PASSWORD properties must also be set. If neither of these properties is set, this property is ignored.
This property contains data that is to be passed to the function defined by the CALLBACK_FUNCTION property when a callback is initiated. The data contained in the variable is defined and set by the caller. When a callback is initiated, this data is passed, unmodified, directly to callback function. Data can be of any type supported by IDL variables including numerical, string, pointer and structure data. If this property is not set, the GetCapabilities, DescribeCoverage, and GetCoverage methods will pass the integer value zero to the callback function.
This property is the name of the .pro code function to be called when GetCapabilities, DescribeCoverage, and GetCoverage, methods are retrieving information from the remote server. The function provides status information in addition to providing a way to cancel an operation. If this property is not set, then no callbacks will be made by the previously noted methods. See Using Callbacks with the IDLnetOGCWCS Object for more information.
The default value is a null string.
The IDLnetOGCWCS::GetCapabilities method returns and stores an XML file that contains the coverage offering briefs available on the remote server. Set this property to define the path and filename of this file, minus the extension. The file type extension is automatically set based on the type of file downloaded (typically .xml). If this property stays the same between calls to GetCapabilities, the last file received is overwritten.
This property defaults to a file named cap, located in your application user directory. If a file was returned by the most recent call to the GetCapabilities method, the LAST_FILE property will contain the full path and filename of the downloaded file.
| Note Do not include a file type extension in the filename. If the retrieved file does not have the same extension as that given, the name will be appended with the file type extension of the received file (but this property will remain unchanged). For example, if you include the . xml extension (cap.xml) and the file received is an HTML file, the filename of the file on disk will be cap.xml.html, while this property remains cap.xml. Always omit the file type extension to avoid such inconsistencies. |
This property cannot be set to a null string.
This property controls how long to wait for a successful connection to an OGC server before ending the attempt to establish a connection. The default is 180 seconds.
Set this read-only property to a variable that will indicate the document type of the last file received as a result of an HTTP GET request. The property is extracted from the contents of the Content-Type field found in an HTTP response header.
The IDLnetOGCWCS::GetCoverage method returns and stores a data file from the WCS server. Set this property to define the path and filename of this file, minus the extension. The file type extension is automatically set based on the type of file downloaded. If this property stays the same (the path and filename are unchanged, and the same type of file is retrieved) between calls to GetCoverage, the last file received is overwritten.
This property defaults to a file named cov, located in your application user directory. If a file was returned by the most recent call to the GetCoverage method, the LAST_FILE property will contain the full path and filename of the downloaded file.
| Note Do not include a file type extension in the filename. If the retrieved file does not have the same extension as that given, the name will be appended with the file type extension of the received file (but this property will remain unchanged). For example, if you include the . tiff extension (cov.tiff) and the file received is an .gml file, the filename of the file on disk will be cov.tiff.gml, while this property remains cov.tiff. Always omit the file type extension to avoid such inconsistencies. |
This property cannot be set to a null string.
The IDLnetOGCWCS::DescribeCoverage method returns and stores an XML file that contains the coverage offerings available on the remote server. Set this property to define the path and filename of this file, minus the extension. The file type extension is automatically set based on the type of file downloaded (typically .xml). If this property stays the same between calls to DescribeCoverage, the last file received is overwritten.
This property defaults to a file named descov, located in your application user directory. If a file was returned by the most recent call to the DescribeCoverage method, the LAST_FILE property will contain the full path and filename of the downloaded file.
| Note Do not include a file type extension in the filename. If the retrieved file does not have the same extension as that given, the name will be appended with the file type extension of the received file (but this property will remain unchanged). For example, if you include the . xml extension (descov.xml) and the file received is an HTML file, the filename of the file on disk will be descov.xml.html, while this property remains descov.xml. Always omit the file type extension to avoid such inconsistencies. |
This property cannot be set to a null string.
This property determines if a compressed or encoded response will be requested from a remote OGC WCS server (during GetCapabilities, DescribeCoverage, and GetCoverage method calls). By default, the IDLnetOGCWCS object requests an unencoded response (ENCODE=0) in order to reduce the number of bytes that need to be sent over the network.
| Note The server does not have to respond with compressed or encoded data. You can determine the encoding, if any, by examining the "Content-Encoding" header in the response. See the VERBOSE property for information on how to access such information. |
Allowable values are:
| Note This property is set automatically and need not be modified unless you have specific HTTP header information that you want included in a GET request sent to a remote WCS server. |
| Warning This property is automatically set to the default value (clearing any custom header information) after a call to any IDLnetOGCWCS::Get* method except GetProperty. Clearing the HEADERS property prevents the inadvertent use of custom header values in future calls to Get methods. |
Set this property to a string or array of strings containing one or more valid header fields and values separated by a colon. Each string in the string array should contain a single header field.
The HTTP header Host, Accept, and Encode fields are set by default. To add, disable or modify headers, do one of the following:
HEADERS="Accept:" disables the header field.
HEADERS="Accept:''" clears the field contents.
Set this property to an empty string to clear all custom headers and reset default values if appropriate. For example, HEADERS='' clears all custom changes.
| Note This method cannot be used to modify the first method line of a HTTP request (typically GET or POST). |
Retrieving this property will return only those headers set using the Init or SetProperty methods. Use the VERBOSE keyword to see the default header information included in a request.
This property contains the full path and filename of the file retrieved from the last successful call to one of the GetCapabilities, GetCoverage, or DescribeCoverage methods. If the most recent call did not return a file, this property will contain a null string. The default value is an empty string.
This property contains the password required for successful authentication with a secure WCS server. The default value is an empty string.
This property specifies the type of authentication that will be used when connecting to a proxy server. Supported authentication modes are:
When PROXY_AUTHENTICATION is set and you are using a proxy server, the PROXY_USERNAME and PROXY_PASSWORD properties must also be set. If either of these properties are not set, then this property is ignored.
This property specifies the hostname or IP address of the proxy server. This property must be set when connecting to an intranet or the internet through a proxy server. The default value is an empty string.
This property contains the password required for successful authentication with a secure proxy server. The default value is an empty string.
This property specifies the TCP/IP port that the proxy server listens to for incoming requests. The default value is "80", the standard port for an HTTP request. This property must be set when connecting to an intranet or the internet through a proxy server.
This property contains the username required for successful authentication with a secure proxy server. The default value is an empty string.
This read-only property contains the HTTP response header from the last request made to an OGC WCS server. The default value is an empty string.
Set this property to the full path and filename of the file containing one or more certificates to be verified with the peer when communicating with a secure server. The default location is IDL_DIR/bin/bin.platform directory where IDL_DIR is your IDL installation directory. A default bundle of Certificate Authority (CA) certificates is installed in this location. Use this property to specify the location of an alternate certificate file.
When negotiating a SSL connection, the server sends a certificate indicating its identity. Use this property to determine whether you have connected to the expected server as follows:
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0
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No verification. The connection succeeds regardless of the name fields in the certificate.
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1
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Verify server. When this property is non-zero, the Common Name field or a Subject Alternate Name field in the certificate must match the host name in the URL (the URL_HOSTNAME property), or the connection fails. The default.
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| Note To guard against a dishonest server, authenticate its certificate. See SSL_VERIFY_PEER. |
SSL peer authentication depends on verification of a chain of digital signatures contained in one or more Certificate Authority (CA) certificates. See SSL_CERTIFICATE_FILE for information on the default CA certificates installed with IDL and how to supply your own certificates.
| Note Certificate authentication is typically used in conjunction with server verification. See SSL_VERIFY_HOST for details. |
This property controls how long to wait for the transmission from the OGC server to complete before ending the attempt. The default is 1800 seconds.
This property specifies the host name or IP address of the remote OGC WCS server.
| Note This property and the URL_PATH property must be set before calling GetCapabilities, DescribeCoverage, or GetCoverage. The hostname and path elements are integral components of the request that is sent to the WCS server. |
You can either set this property manually or pass a URL to the IDLnetOGCWCS::ParseUrl method. See Translating a URL into Property Values for more information. The default value is an empty string.
This property specifies the path to the remote OGC WCS server.
| Note This property and the URL_HOSTNAME property must be set before calling GetCapabilities, DescribeCoverage, or GetCoverage. The path and hostname elements are integral components of the request that is sent to the WCS server. |
You can either set this property manually or pass a URL to the IDLnetOGCWCS::ParseUrl method. See Translating a URL into Property Values for more information. The default value is an empty string.
This property specifies the TCP/IP port at which the remote server listens for incoming requests. You can either set this property manually or pass a URL to the IDLnetOGCWCS::ParseUrl method. See Translating a URL into Property Values for more information. The default value is "80", the standard port for an HTTP request.
This property specifies a prefix containing additional query information that will be prepended to the main portion of a request. You can either set this property manually or pass a URL to the IDLnetOGCWCS::ParseUrl method. See Translating a URL into Property Values for more information. The default value is an empty string.
This property specifies a suffix containing additional query information that will be appended to the main portion of a request. See Translating a URL into Property Values for more information on this property. The default value is an empty string.
This property specifies the name of the protocol used to communicate with the remote WCS server when a request is made. You can either set this property manually or pass a URL to the IDLnetOGCWCS::ParseUrl method. See Translating a URL into Property Values for more information. Possible values are:
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String Value
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Description
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This is the default.
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Use this setting when making a secure request and Secure Socket Layer (SSL) is supported by the remote WCS server. See SSL_CERTIFICATE_FILE, SSL_VERIFY_HOST, and SSL_VERIFY_PEER for SSL-related configuration parameters.
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This property contains the username required for successful authentication with a secure WCS server. The default value is an empty string.
Set this property to return connection and HTTP header information associated with a IDLnetOGCWCS::GetCapabilities, IDLnetOGCWCS::DescribeCoverage, or IDLnetOGCWCS::GetCoverage method request.
To access this information, the CALLBACK_FUNCTION property must also be set. The callback function's StatusInfo variable will contain:
Each message is limited to 512 bytes of text. The default value is 0.
| Note For a simple example of using a callback to return VERBOSE status information, see IDLnetOGCWCS::GetCapabilities. |
This property defines the version of the OGC WCS standard supported by the IDLnetOGCWCS object. The only valid value is "Version=1.0.0" for all requests.
IDL Online Help (March 06, 2007)