(PureBasic) Shopify OAuth2 Authentication

See more OAuth2 Examples

This example shows how to obtain an initial access token for a Shopify application using OAuth2 authentication specifically for non-web applications. This process requires displaying a browser window to secure user authorization. In contrast, web-based applications use a different method to obtain an OAuth2 token, as they redirect back to the application via a URL. Note: Once you have the access token, all subsequent Chilkat examples that rely on an already-obtained token are applicable to both web and non-web applications.

Note: This example requires Chilkat v10.1.2 or greater.

Chilkat PureBasic Module Download

Chilkat PureBasic Module

IncludeFile "CkOAuth2.pb"
IncludeFile "CkStringBuilder.pb"

Procedure ChilkatExample()

    ; To further clarify, see OAuth 2.0 Authorization Flow

    oauth2.i = CkOAuth2::ckCreate()
    If oauth2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; This should be the port in the localhost callback URL for your app.  
    ; The callback URL would look like "http://localhost:3017/" if the port number is 3017.
    ; Make sure that "http://localhost:3017/" is listed in your Whitelisted Redirection URLs for your Shopify app.
    CkOAuth2::setCkListenPort(oauth2, 3017)

    ; The full content of the Authorization Endpoin for Shopify looks like this:
    ; https://{shop}.myshopify.com/admin/oauth/authorize?client_id={api_key}&scope={scopes}&redirect_uri={redirect_uri}&state={nonce}&grant_options[]={option}

    ; Replace "chilkat" with your shop name.
    CkOAuth2::setCkAuthorizationEndpoint(oauth2, "https://chilkat.myshopify.com/admin/oauth/authorize")
    CkOAuth2::setCkTokenEndpoint(oauth2, "https://chilkat.myshopify.com/admin/oauth/access_token")

    ; Replace this with your actual API KEY (client ID)
    CkOAuth2::setCkClientId(oauth2, "SHOPIFY_API_KEY")

    ; This is for Require Proof Key for Code Exchange (PKCE)
    ; See OAuth2 PKCE Explained
    CkOAuth2::setCkCodeChallenge(oauth2, 1)
    CkOAuth2::setCkCodeChallengeMethod(oauth2, "S256")

    ; Set requested scopes.  See https://help.shopify.com/api/getting-started/authentication/oauth
    CkOAuth2::setCkScope(oauth2, "read_product_listings,read_customers,read_orders,read_draft_orders")

    ; Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
    url.s = CkOAuth2::ckStartAuth(oauth2)
    If CkOAuth2::ckLastMethodSuccess(oauth2) <> 1
        Debug CkOAuth2::ckLastErrorText(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    ; Launch the default browser on the system and navigate to the url.
    ; The LaunchBrowser method was added in Chilkat v10.1.2.
    success.i = CkOAuth2::ckLaunchBrowser(oauth2,url)
    If success = 0
        Debug CkOAuth2::ckLastErrorText(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    ; Wait for the user to approve or deny authorization in the browser.
    numMsWaited.i = 0
    While (numMsWaited < 90000) AND (CkOAuth2::ckAuthFlowState(oauth2) < 3)
        CkOAuth2::ckSleepMs(oauth2,100)
        numMsWaited = numMsWaited + 100
    Wend

    ; If the browser does not respond within the specified time, AuthFlowState will be:
    ; 
    ; 1: Waiting for Redirect – The OAuth2 background thread is waiting for the browser's redirect request.
    ; 2: Waiting for Final Response – The thread is awaiting the final access token response.
    ; In either case, cancel the background task initiated by StartAuth.

    If CkOAuth2::ckAuthFlowState(oauth2) < 3
        CkOAuth2::ckCancel(oauth2)
        Debug "No response from the browser!"
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    ; Check AuthFlowState to determine if authorization was granted, denied, or failed:
    ; 
    ; 3: Success – OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
    ; 4: Access Denied – OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
    ; 5: Failure – OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

    If CkOAuth2::ckAuthFlowState(oauth2) = 5
        Debug "OAuth2 failed to complete."
        Debug CkOAuth2::ckFailureInfo(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    If CkOAuth2::ckAuthFlowState(oauth2) = 4
        Debug "OAuth2 authorization was denied."
        Debug CkOAuth2::ckAccessTokenResponse(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    If CkOAuth2::ckAuthFlowState(oauth2) <> 3
        Debug "Unexpected AuthFlowState:" + Str(CkOAuth2::ckAuthFlowState(oauth2))
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    Debug "OAuth2 authorization granted!"
    Debug "Access Token = " + CkOAuth2::ckAccessToken(oauth2)

    ; Save the full JSON access token response to a file.
    sbJson.i = CkStringBuilder::ckCreate()
    If sbJson.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkStringBuilder::ckAppend(sbJson,CkOAuth2::ckAccessTokenResponse(oauth2))
    CkStringBuilder::ckWriteFile(sbJson,"qa_data/tokens/shopify-access-token.json","utf-8",0)

    ; The saved JSON response looks like this:

    ; {
    ;   "access_token": "1364e43a5332583188cb27bc85469b1f",
    ;   "scope": "read_product_listings,read_customers,read_orders,read_draft_orders"
    ; }


    CkOAuth2::ckDispose(oauth2)
    CkStringBuilder::ckDispose(sbJson)


    ProcedureReturn
EndProcedure