(C) Using Replace Patterns in Email

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Demonstrates how to use the replace patterns (mail-merge) feature in Chilkat MailMan.

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#include <C_CkEmail.h>
#include <C_CkMailMan.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkEmail emailTemplate;
    HCkMailMan mailman;
    const char *mime;
    int count;
    int i;
    const char *name;
    HCkJsonObject json;
    const char *emailAddr;
    const char *firstName;
    const char *product;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // ---------------------------------------------------------------------
    // Create an email template for sending.
    emailTemplate = CkEmail_Create();

    // We're going to replace "FIRST_NAME" with an actual name.
    // We arbitrarily chose "FIRST_NAME".  We can choose anything, such as "CUSTOMER_NAME" or "THE_RECIPIENT_NAME"...
    CkEmail_putSubject(emailTemplate,"Hello FIRST_NAME,");

    CkEmail_putFrom(emailTemplate,"john@example.com");
    CkEmail_AddTo(emailTemplate,"FIRST_NAME","RECIPIENT_EMAIL");

    CkEmail_SetHtmlBody(emailTemplate,"<html><body><h2>Hello FIRST_NAME,</h2><p>Your order for PRODUCT_NAME has been shipped.</p></body></html>");

    // If the email is saved to a file, we can see what it contains:
    CkEmail_SaveEml(emailTemplate,"qa_output/emailTemplate.eml");

    // For example:

    // MIME-Version: 1.0
    // Date: Tue, 26 Apr 2022 07:10:52 -0500
    // Message-ID: <715CF231A9F07B0B9FDB073518CD94138D791866@XYZ>
    // Content-Type: text/html; charset=us-ascii
    // Content-Transfer-Encoding: 7bit
    // X-Priority: 3 (Normal)
    // Subject: Hello FIRST_NAME,
    // From: john@example.com
    // CKX-Bounce-Address: john@example.com
    // To: FIRST_NAME <RECIPIENT_EMAIL>
    // 
    // <html><body><h2>Hello FIRST_NAME,</h2><p>Your order for PRODUCT_NAME has been shipped.</p></body></html>

    // Note: Ignore the CKX-Bounce-Address header.  It is automatically removed by Chilkat prior to sending.
    // All "CKX-" headers are automatically removed prior to sending.

    // ---------------------------------------------------------------------
    // Demonstrate replace patterns by setting and then rendering to MIME.

    mailman = CkMailMan_Create();

    CkEmail_SetReplacePattern(emailTemplate,"FIRST_NAME","Elon");
    CkEmail_SetReplacePattern(emailTemplate,"RECIPIENT_EMAIL","elon.musk@example.com");
    CkEmail_SetReplacePattern(emailTemplate,"PRODUCT_NAME","Twitter Corporation");

    // Render to MIME to see what we get.
    // Note: When the MailMan sends an email, it renders the email to MIME and then sends.
    // The rendering process is to do replacements, or possibly sign, encrypt, etc.
    // When MailMan.SendEmail is called, internally the email is rendered, and the rendered email is sent.
    // The equivalent to MailMan.Send email is to call email.RenderToMime followed by MailMan.SendMime.
    mime = CkMailMan_renderToMime(mailman,emailTemplate);
    printf("%s\n",mime);

    // This is the rendered MIME:

    // MIME-Version: 1.0
    // Date: Tue, 26 Apr 2022 07:25:49 -0500
    // Message-ID: <750582BCDC891C67B48CEE2293C08B902C3891E9@XYZ>
    // Content-Type: text/html; charset=us-ascii
    // Content-Transfer-Encoding: 7bit
    // X-Priority: 3 (Normal)
    // Subject: Hello Elon,
    // From: john@example.com
    // To: Elon <elon.musk@example.com>
    // 
    // <html><body><h2>Hello Elon,</h2><p>Your order for Twitter Corporation has been shipped.</p></body></html>

    // Note: When rendering, the Date and Message-ID headers are automatically regenerated.

    // ---------------------------------------------------------------------
    // An application can see what replacement patterns it previously set by calling SetReplacePattern multiple times.
    count = CkEmail_getNumReplacePatterns(emailTemplate);
    printf("Number of replace patterns: %d\n",count);

    i = 0;
    while (i < count) {
        // Note: The GetReplaceString method was found to not be working correctly.  It was returning the same value as GetReplacePattern.
        // It is fixed in Chilkat v9.5.0.91
        printf("%s: %s\n",CkEmail_getReplacePattern(emailTemplate,i),CkEmail_getReplaceString(emailTemplate,i));
        i = i + 1;
    }

    // Or lookup a replacement pattern by name:
    name = "FIRST_NAME";
    printf("%s = %s\n",name,CkEmail_getReplaceString2(emailTemplate,name));

    // Sample output:

    // Number of replace patterns: 3
    // FIRST_NAME: Elon
    // RECIPIENT_EMAIL: elon.musk@example.com
    // PRODUCT_NAME: Twitter Corporation
    // FIRST_NAME = Elon

    // ---------------------------------------------------------------------
    // Finally... demonstrate sending emails using the replacement patterns.
    // 

    // Set our mail server settings..
    CkMailMan_putSmtpHost(mailman,"smtp.mail.us-west-2.awsapps.com");
    CkMailMan_putSmtpSsl(mailman,TRUE);
    CkMailMan_putSmtpPort(mailman,465);

    CkMailMan_putSmtpUsername(mailman,"john@example.com");
    CkMailMan_putSmtpPassword(mailman,"the_password");

    // Imagine we have data in JSON format, and we wish to send the templated email to each recipient...
    // 

    // {
    // 	"mail_merge" : [
    // 		{
    // 			"to": "mary@example.com",
    // 			"name": "Mary",
    // 			"product": "Widget 1" 
    // 		},
    // 		{
    // 			"to": "robert@example.com",
    // 			"name": "Robert",
    // 			"product": "Widget 2"
    // 		}	
    // 		...
    // 	]
    // }

    json = CkJsonObject_Create();
    success = CkJsonObject_LoadFile(json,"qa_data/json/mail_merge.json");
    if (success == FALSE) {
        printf("%s\n",CkJsonObject_lastErrorText(json));
        CkEmail_Dispose(emailTemplate);
        CkMailMan_Dispose(mailman);
        CkJsonObject_Dispose(json);
        return;
    }

    i = 0;
    count = CkJsonObject_SizeOfArray(json,"mail_merge");
    while (i < count) {
        CkJsonObject_putI(json,i);
        emailAddr = CkJsonObject_stringOf(json,"mail_merge[i].to");
        firstName = CkJsonObject_stringOf(json,"mail_merge[i].name");
        product = CkJsonObject_stringOf(json,"mail_merge[i].product");

        CkEmail_SetReplacePattern(emailTemplate,"FIRST_NAME",firstName);
        CkEmail_SetReplacePattern(emailTemplate,"RECIPIENT_EMAIL",emailAddr);
        CkEmail_SetReplacePattern(emailTemplate,"PRODUCT_NAME",product);

        success = CkMailMan_SendEmail(mailman,emailTemplate);
        if (success == FALSE) {
            printf("%s\n",CkMailMan_lastErrorText(mailman));
            CkEmail_Dispose(emailTemplate);
            CkMailMan_Dispose(mailman);
            CkJsonObject_Dispose(json);
            return;
        }

        printf("Send email to %s\n",emailAddr);

        i = i + 1;
    }

    printf("Success.\n");


    CkEmail_Dispose(emailTemplate);
    CkMailMan_Dispose(mailman);
    CkJsonObject_Dispose(json);

    }