PowerScript Reference
PowerScript Functions

Description

Retrieves data to the DataWindow, DataWindowChild, or DataStore from the RESTFul Web service according to the key name of the JSON string. If the data received from the RESTful web service is compressed as gzip, it will be automatically decompressed. Only gzip compression format is supported at this moment. The developer can use the SetRequestHeader function to set the Accept-Encoding header to allow only the gzip compression format.

Applies to

RestClient object

Syntax

objectname.Retrieve ( dwControl, urlName {, data} {, tokenrequest} )

Usage

The Retrieve function retrieves data only when the JSON key name matches with the DataWindow column name; if none of the JSON key name matches with any of the DataWindow column name, then no data will be inserted into the DataWindow and the function returns error code -17.

For the Retrieve function, the JSON string returned from the RESTFul Web service APIs must be an array in the two-level plain JSON format (see Plain JSON: two-level structure in Application Techniques for details); for the RetrieveOne function, the JSON string returned from the RESTFul Web service APIs can be an array in the two-level plain JSON format (see Plain JSON: two-level structure in Application Techniques for details) or a JSON object.

The Retrieve function is not supported in DataWindow/DataWindowChild/DataStore with the following presentation styles: Composite, Crosstab, OLE 2.0, and RichText.

Although the Retrieve function is not supported in the Composite DataWindow, you can call GetChild function to get the child DataWindow from the Composite DataWindow, and then call the Retrieve function to retrieve the data into the child DataWindow.

The Retrieve function will not trigger the DataWindow RetrieveRow event considering the performance effect, although it will trigger the RetrieveStart and RetrieveEnd events.

Return value

Long.

Returns values as follows. If any argument's value is null, the method returns null.

>=0 -- Returns the number of rows if it succeeds

-1 -- General error

-2 -- Invalid URL

-3 -- Cannot connect to the Internet

-4 -- Timed out

-5 -- Get token error

-7 -- Failed to automatically decompress the response body

-10 -- The token is invalid or has expired

-15 -- Unsupported character sets

-16 -- The JSON is not a plain JSON with two-level structure

-17 -- No data is inserted into the DataWindow because no key in the JSON matches any column name in it

Example 1

This example retrieves data to a DataWindow:

long ll_return
RestClient lnv_RestClient
lnv_RestClient = Create RestClient

// Set DataObject
dw_emp.DataObject = "d_sq_gr_emp"

// Send request using GET
ll_return = lnv_RestClient.Retrieve(dw_emp, "http://demo.appeon.com/PB/webapi_client/employee/102")

// Check the return value
if ll_return >= 0 then
 MessageBox("Success", "Rows = " + String(ll_return))
else
 MessageBox("Error", "Failed to retrieve data.")
end if

Example 2

This example retrieves data to a DataStore:

long ll_return
RestClient lnv_RestClient
datastore lds_datastore

lnv_RestClient = Create RestClient
lds_datastore = create datastore

// Set DataObject
lds_datastore.DataObject = "d_sq_gr_emp"

// Send request using GET
ll_return = lnv_RestClient.Retrieve(lds_datastore, "http://demo.appeon.com/PB/webapi_client/employee/102")

// Check the return value
if ll_return >= 0 then
 MessageBox("Success", "Rows = " + String(ll_return))
else
 MessageBox("Error", "Failed to retrieve data.")
end if

Example 3

This example retrieves data to a DataWindowChild:

int li_return
RestClient lnv_restClient
DataWindowChild ldwc_dept

lnv_restClient = create RestClient

//get the DataWindowChild
dw_emp.getchild("dept_id", ldwc_dept)

//Get data from web api using GET method
li_return = lnv_restClient.retrieve(ldwc_dept, "http://demo.appeon.com/pb/webapi_client/department")

if li_return >= 0 then
 messagebox("Success", "Rows =  " + string(li_return))
else
 messagebox("Error", "Failed to retrieve data.")
end if

Example 4

This example passes the string data using POST method and retrieves data to a DataWindow.

long ll_return
RestClient lnv_RestClient
lnv_RestClient = Create RestClient

String ls_json = '{"empId":100, "fname":" John", "lname": "Guevara"}'

// Construct a POST request (supports all headers)
lnv_RestClient.SetRequestHeader("Content-Type", "application/json;charset=UTF-8")

// Send the POST request (add data to the body and automatically set Content-Length header)
ll_return = lnv_RestClient.Retrieve(dw_emp, "http://demo.appeon.com/PB/webapi_client/employee", ls_Json)

// Check the return value
if ll_return >= 0 then
 MessageBox("Success", "Rows = " + String(ll_return))
else
 MessageBox("Error", "Failed to retrieve data.")
end if

Example 5

This example passes the blob data using POST method and retrieves data to a DataWindow.

Long ll_rc
Blob lblb_data
RestClient lnv_RestClient 
lnv_RestClient = Create RestClient

// Set DataObject
dw_1.DataObject = "d_employee"

// Construct a POST request (supports all headers)
lnv_RestClient.SetRequestHeader("Content-Type", "application/json;charset=UTF-8")
// Content-Length is set by Retrieve automatically
// ...
lblb_data = blob('{"empId":100, "fname":"John", "lname":"Guevara"}', EncodingUTF8!)

// Send the POST request (add data to the body and automatically set Content-Length header)
ll_rc = lnv_RestClient.Retrieve(dw_1, "http://demo.appeon.com/PB/webapi_client/employee/blob", lblb_data)

// Check the return value
if ll_rc >= 0 then
 MessageBox("Success", "Rows = " + String(ll_rc))
else
 MessageBox("Error", "Failed to retrieve data.")
end if

Example 6

This example passes the string data using POST method and retrieves data to a DataStore.

String ls_json
Long ll_rc
Datastore lds_1 
RestClient lnv_RestClient 
lnv_RestClient = Create RestClient

lds_1 = Create Datastore
lds_1.DataObject = "d_employee"

ls_json = '{"city": "Needham", "state": "MA", zipCode": "02192"}'

// Construct a POST request (supports all headers)
lnv_RestClient.SetRequestHeader("Content-Type", "application/json;charset=UTF-8")
// Content-Length is set by Retrieve automatically
// ...
// Send the POST request (add data to the body and automatically set Content-Length header)
ll_rc = lnv_RestClient.Retrieve(lds_1, "http://demo.appeon.com/PB/webapi_client/employee", ls_Json)

// Check the return value
if ll_rc >= 0 then
 MessageBox("Success", "Rows = " + String(ll_rc))
else
 MessageBox("Error", "Failed to retrieve data.")
end if

Example 7

This example passes the blob data using POST method and retrieves data to a DataStore.

Long ll_rc
RestClient lnv_RestClient 
lnv_RestClient = Create RestClient 
blob lblb_data
Datastore lds_1
lds_1 = Create Datastore

// Set DataObject
lds_1.DataObject = "d_employee"

// Construct a POST request (supports all headers)
lnv_RestClient.SetRequestHeader("Content-Type", "application/json;charset=UTF-8")
// Content-Length is set by Retrieve automatically
// ...
lblb_data = blob('{"empId":100, "fname":"John", "lname":"Guevara"}', EncodingUTF8!)
// Send the POST request (add data to the body and automatically set Content-Length header)
ll_rc = lnv_RestClient.Retrieve(lds_1, "http://demo.appeon.com/PB/webapi_client/employee/blob", lblb_data)

// Check the return value
if ll_rc >= 0 then
 MessageBox("Success", "Rows = " + String(ll_rc))
else
 MessageBox("Error", "Failed to retrieve data.")
end if

Example 8

This example passes the string data using POST method and retrieves data to a DataWindowChild.

int li_return
string ls_data
RestClient lnv_restClient
DataWindowChild ldwc_dept
lnv_restClient = create RestClient

//Get DataWindowChild
dw_emp.getchild("dept_id", ldwc_dept)

ls_data  = "{'id':100}"
lnv_restClient.SetRequestHeader("Content-Type", "application/json;charset=UTF-8")
//Get data from web api using POST method

li_return = lnv_restClient.retrieve(ldwc_dept, "http://demo.appeon.com/pb/webapi_client/department/RetrievePassJson", ls_data)

if li_return >= 0 then
        messagebox("Success", "Rows =  " + string(li_return))
else
        messagebox("Error", "Failed to retrieve data.")
end if

Example 9

This example passes the blob data using POST method and retrieves data to a DataWindowChild.

int li_return
blob lblb_data
RestClient lnv_restClient
DataWindowChild ldwc_dept

lnv_restClient = create RestClient
lnv_restClient.setrequestheader("Content-Type", "Application/json;charset=utf-8")

//Convert the string to a blob
lblb_data = blob("{'id':100}", encodingutf8!)

//Get DataWindowChild
dw_emp.getchild("dept_id", ldwc_dept)

//Pass data from web api using POST method
li_return = lnv_restClient.retrieve(ldwc_dept, "http://demo.appeon.com/pb/webapi_client/department/RetrievePassJson", lblb_data)

if li_return >= 0 then
        messagebox("Success", "Rows =  " + string(li_return))
else
        messagebox("Error", "Failed to retrieve data.")
end if

Example 10

This example gets data from a Web site with token authentication and then retrieves data to a DataWindow.

integer li_return
RestClient lnv_restClient
TokenRequest lnv_tokenRequest

lnv_restClient = create RestClient
lnv_TokenRequest.tokenlocation = "http://demo.appeon.com/pb/identityserver/connect/token" //Location of the token
lnv_TokenRequest.method = "post" //Request method
lnv_TokenRequest.granttype = "client_credentials" //Grant type
lnv_TokenRequest.clientid = "GRfjNAfCg2bI47l1sX5zdFiTEmdrkCKa20zm5YVS4iM=" //client ID
lnv_TokenRequest.clientsecret = "K7gNU3sdo-OL0wNhqoVWhr3g6s1xYv72ol/pe/Unols=" //client certificate

li_return = lnv_restClient.retrieve(dw_dept, "http://demo.appeon.com/pb/webapi_client/identity/departments", lnv_tokenRequest)

if li_return >= 0 then
        messagebox("Success", "Rows " + string(li_return))
else
        messagebox("Error", "Failed to retrieve data.")
end if

Example 11

This example passes the blob data using POST method and retrieves the data from the Web site with token authentication to the DataWindow.

integer li_return
blob lblb_data
RestClient lnv_restClient
TokenRequest lnv_tokenRequest

lnv_restClient = create RestClient

lnv_TokenRequest.tokenlocation = "http://demo.appeon.com/pb/identityserver/connect/token" //Location of the token
lnv_TokenRequest.method = "post" //Request method
lnv_TokenRequest.granttype = "client_credentials" //Grant type
lnv_TokenRequest.clientid = "GRfjNAfCg2bI47l1sX5zdFiTEmdrkCKa20zm5YVS4iM=" //client ID
lnv_TokenRequest.clientsecret = "K7gNU3sdo-OL0wNhqoVWhr3g6s1xYv72ol/pe/Unols=" //client certificate

lnv_restClient.setrequestheader("Content-Type", "Application/json;charset=utf-8")

lblb_data = blob("{'id':100}", encodingutf8!)

li_return = lnv_restClient.retrieve(dw_dept, "http://demo.appeon.com/pb/webapi_client/identity/department", lblb_data, lnv_tokenRequest)

if li_return >= 0 then
 messagebox("Success", "Rows " + string(li_return))
else
 messagebox("Error", "Failed to retrieve data.")
end if

Example 12

The client sends the server a request which includes the "gzip" compression method; then the server compresses and returns the data as requested; and then the client automatically extracts the data.

Integer      li_Return
RestClient   lrc_Dept

lrc_Dept  =  Create RestClient

lrc_Dept.SetRequestHeader("Content-Type", "application/json;charset=UTF-8")
// Sets the compression method in the request header
lrc_Dept.SetRequestHeader("Accept-Encoding","gzip")

// DataWindow column name and type must match with those returned from
// URL: https://demo.appeon.com/PB/webapi_client/department
dw_submit.DataObject = 'd_example_dept'

// dw_submit datawindow will display the return data
li_Return = lrc_Dept.Retrieve(dw_submit,"https://demo.appeon.com/PB/webapi_client/department")

If li_Return < 0 Then
   // Prints the error message
End If

See also

RetrieveOne