matlab.net.http.io.ImageProvider Class

This is the value specified as the Data argument to the constructor, if any, or the data converted from the filename argument. Set this value to a string scalar or character vector before sending the message containing this provider.

If a subclass author wants to set this property before MATLAB calls the start method, then set the value in the complete method. If you change this property, then the change takes effect with the next call to start.

Attributes:

Arguments to the imwrite function, specified as a cell array. This is the value specified to the constructor containing a list of arguments as documented for imwrite, but omitting the image data and file name arguments.

Subclass authors can set this property before MATLAB calls start, for example, in complete. If you change these values, then the changes do not take effect until the next call to start.

Attributes:

Name of the file containing the image data, specified as a string. This is the value specified as the filename argument to the constructor, if any. It is read-only.

The format of filename is derived from the file name extension, which might be different from the fmt argument in arg1,...,argN or the Content-Type in the message. This constructor syntax allows you to send an image file in one format to a server that expects it in a different format. However, some conversions are incompatible. For example, you cannot convert an RGB file like JPEG to a GIF format.

Attributes:

Header fields of the message or part, specified as a vector of one or more matlab.net.http.HeaderField objects.

This property is only used by subclass authors. MATLAB sets this property before calling the provider's complete method. For non-multipart messages, MATLAB initializes this property to the contents of Request.Header, minus any matlab.net.http.field.GenericFields or empty-valued fields. The ContentProvider uses this property to add header fields that describe the data to be sent, or to add parameters to header fields already in the message. In a delegate for a MultipartProvider, MATLAB initializes this property to header fields that the delegating provider intends to insert for the part. Delegates can modify or change these fields.

Upon return from the provider's complete method, if this not a multipart message, then MATLAB reads this property and merges its contents into the header of Request. Fields in this Header with Names that do not already appear in Request.Header are added to the end of Request.Header. If a field in this Header has a Name that is the same as one in Request.Header, and both have nonempty Values, then:

If one or both of these has an empty Value, then the field is removed from Request.Header and it is not added as part of normal message completion.

If this is a delegate of a MultipartProvider, then the entire contents of this Header is used as the header of the part. Multipart delegates must not assume that Request.Header contains any fields pertaining to their own Header. A provider can determine whether it is a multipart delegate by checking whether MyDelegator is a MultipartProvider, though this test is unlikely to be needed.

MATLAB reads this property only on return from calling the provider's complete method. Changes to this array are ignored once MATLAB calls start.

Class authors should be aware that their subclasses might have added fields to this Header (in their complete method) before calling complete in their superclass. It is best to preserve such fields and not to add fields with the same names. However, adding a parameter to a field is permissible. For example, a superclass can add a charset parameter to an existing Content-Type field that does not already have one.

Attributes:

Indicate whether to force chunked transfer coding, specified as boolean. This property is of interest only to subclass authors, and is applicable only to providers that are not multipart delegates. Subclasses set ForceChunked to control whether contents should be sent using chunked transfer coding. If false (default), MATLAB decides whether to send the contents chunked, based on whether it knows the content length at the time the message is ready to be sent:

If ForceChunked is true, then MATLAB sends the message chunked regardless of whether it knows the content length, unless the known length is smaller than the chunk size. If this property is true, then the message must not contain a Content-Length field, because HTTP does not allow a chunked message to have a Content-Length field. However, you can still return a nonzero value in the expectedContentLength method if you want MATLAB to verify that you are returning the expected length of data.

When MATLAB chooses to send the message chunked, the size of each chunk is equal to the length of data returned by getData.

MATLAB reads this value after calling the complete method, before calling start. It does not set this field.

Attributes:

Request message to send, specified as a matlab.net.http.RequestMessage object.

This property is used only by subclass authors. The RequestMessage.send and RequestMessage.complete methods set this property to the RequestMessage in whose Body this provider has been placed, before calling any other methods in this provider, and before adding any additional header fields or validating the message. The provider can examine this message to see what was contained in the original request.

Delegates see the same value for this property as the delegator. ContentProviders should be aware that, if they are delegates, they are not necessarily providing the entire body of the request message, so they should not assume that header fields in this Request are pertinent to the data they are providing. Usually, delegates should ignore header fields in this request relevant to the data, such as Content-Type.

If the provider wishes to add any header fields to this message, or to modify existing ones, it should do so in its complete method by adding those fields to the Header property. The caller of complete (RequestMessage or a delegating provider) determines what to do with those fields. RequestMessage.send and RequestMessage.complete always copy these fields to the Header of the RequestMessage. A delegating provider can copy the fields to its own Header property or insert them into the message (as in the case of MultipartProvider). For more information, see the Header property.

This property is read-only.

Attributes: