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There are four basic methods for creating a resource within the SRP HTTP Framework. You will choose the method that best suits your needs. We will list the pros and cons of each method and provide sample code that creates the same resource using each method.

Method 1:

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Using the GetDatabaseItem Service

For simple database related resources, the GetDatabaseItem service (a member of the HTTP_Resource_Services module) can be used with minimal code. Just get the Key ID from the prepopulated EndpointSegment variable and pass in the name of the database table:

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One of the drawbacks of calling the GetDatabaseItem service is that property names are formatted with underscores (i.e., how they appear in the dictionary) rather than as camel case (which is the conventional format for JSON objects). Another drawback is that the GetDatabaseItem service attempts to return create a resource object from all column data (both physical and calculated). This might be undesirable if some of the data is meaningless to the client. Consider the picture property in the above resource object. It references an image file stored locally on the server, which has no value to the client. This can also be problematic if a calculated column encounters a runtime error or is dependent upon information that only exists within an OpenInsight desktop session. To resolve both of the above items, we will take advantage of the optional ColumnNames and ItemArrayLabel arguments. To keep our sample code simple and concise, we will limit our resource to just the FIRST_NAME, LAST_NAME, ADDRESS, CITY, STATE, and ZIP database columns:

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• Simple to call.
• It creates the response body Response Body, contentContent-type Type header, and status code Status Code automatically.

Cons:

• Deprecated (but there are no plans to remove it).
• HATEOAS support is limited.
• Cannot include the Key ID within the resource object.

Method 2: Using the GetObject Service

GetDatabaseItem is an example of a high-level service. That is, it relies upon a simple interface and default behavior. Like other high-level services, GetDatabaseItem is built on top of slightly lower-level services. The most important one of these is GetObject. (which is also a member of the HTTP_Resource_Services module). Let's look at an example of an API that uses the GetObject service to produce the same resource as the GetDatabaseItem service:

API contacts.ID.GET

    KeyID           = EndpointSegment

    ColumnNames     = 'FIRST_NAME' : @FM : 'LAST_NAME' : @FM : 'ADDRESS' : @FM : 'CITY' : @FM : 'STATE' : @FM : 'ZIP'
    PropertyNames   = 'firstName' : @FM : 'lastName' : @FM : 'address' : @FM : 'city' : @FM : 'state' : @FM : 'zipCode'
    // Create a JSON object in memory.
    objResource     = HTTP_Resource_Services('GetObject', 'CONTACTS', KeyID, ColumnNames, PropertyNames)
    If Error_Services('NoError') then
        // Serialize the JSON object.
        jsonResource    = HTTP_Resource_Services('GetSerializedResource', objResource)
        // Set the response body with the serialized JSON object and set the Content-Type response header.
        HTTP_Services('SetResponseBody', jsonResource, False$, 'application/hal+json')
    end else
        // There is an error condition so call the SetResponseError service.
        HTTP_Services('SetResponseError', '', '', 500, Error_Services('GetMessage'), FullEndpointURL)
    end

end api

In many ways, GetObject and GetDatabaseItem are the same. As demonstrated in the code below, their arguments are very similar. GetObects differs from GetDatabaseItem in the following ways:

This produces the following resource object: