Merge pull request #44 from tariq1890/master

Adding Usage.md for smtpapi-go

Author: Kaylyn Sigler

USAGE.md

@@ -0,0 +1,276 @@
+# Usage
+
+## Initialisation
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/sendgrid/smtpapi-go"
+)
+
+header := smtpapi.NewSMTPAPIHeader()
+```
+
+## Table of Contents
+
+- [Recipients](#recipients)
+- [Categories](#categories)
+- [Substitution](#substitution)
+- [Sections](#sections)
+- [Filters](#filters)
+- [Advanced Suppression Manager (ASM)](#asm)
+- [Send At](#send-at)
+- [Batches](#batches)
+- [IP Pools](#ip-pools)
+- [Retrieving Data](#retrieving-data)
+
+<a name="recipients"></a>
+## Recipients
+
+#### Adding a single recipient
+
+The `header.AddTo` method allows you to add a new recipient to the `To` array.
+
+To do this, you can use the function with an email address, and optionally include the recipient's name as a second parameter.
+
+```go
+header.SetTo("[email protected]") // An email address with no name provided
+header.SetTo("[email protected]", "An Example User")  // An email address with a name provided as the second parameter
+```
+
+#### Setting multiple recipients
+
+The `header.SetTos` method allows you to set multiple recipients by providing an array of email addresses.
+
+This will set the `To` array to the array you provide. This will need to either be an array of emails, or if names are provided, they need to be formatted as `{{ name }} <{{ email }}>`.
+
+```go
+header.SetTos([]string{
+    "[email protected]", // An email address with no name
+    "An Example User <[email protected]>", // An email with a name field
+})
+```
+
+<a name="categories"></a>
+## Categories
+
+Categories are a useful way to organise your email analytics by tagging your emails with a specific type or topic.
+
+There are multiple methods available for setting your categories when sending emails.
+
+#### Adding a single category
+
+The `header.AddCategory` method can be used to add a category to your list.
+
+```go
+header.AddCategory('marketing') // Add a new category of 'marketing' to the array of categories
+```
+
+#### Setting multiple categories
+
+The `header.SetCategories` method can be used to set your categories list to an array of strings.
+
+This is useful when there are a set amount of categories required for the email you are sending.
+
+This method will remove any categories that have been previously set.
+
+```go
+header.SetCategories([]string{
+    "marketing",
+    "sales",
+}) // Sets the current categories to be 'marketing' and 'sales'
+```
+
+#### Setting a single category
+
+The `header.SetCategory` method can be used to set a single specific category.
+
+It is useful for removing previously set categories. And will create a new array with the string you provide.
+
+This method will remove any categories that have been previously set.
+
+```go
+header.SetCategory("marketing") // Reset the categories to be 'marketing' only
+```
+
+<a name="substitution"></a>
+## Substitution
+
+Substitutions are a great way of writing short dynamic email content easily,
+
+#### Adding a single substitution string
+
+The `header.AddSubstitution` method can be used to replace content for recipients.
+
+```go
+header.AddSubstitution("-name-", "John") // Replace the -name- variable with John.
+```
+
+#### Setting substitution strings
+
+The `header.SetSubstitutions` method can be used to replace content for any number of strings.
+
+This method will reset any key pairs that have previously been set.
+
+```go
+header.SetSubstitutions(map[string][]string{
+    "-name-":   {"John", "Jane"}, // Replace the -name- variable to John or Jane
+    "-number-": {"555.555.5555", "777.777.7777"}, // Replace the -number- variable with the provided numbers
+})
+```
+
+<a name="sections"></a>
+## Sections
+
+Sections are similar to substitutions, but are specific to the actual message rather than the recipient.
+
+This is useful when you are sending multiple emails with the same style, but different content.
+
+Note that substitution variables can also be included within a section, but section variables cannot
+
+#### Adding a section
+
+The `header.AddSection` method can be used to add a new section to the sections array. This is useful for building up a list of sections dynamically, perhaps based on a user's actions.
+
+```go
+header.AddSection("-event_details-", "The event will be held tomorrow.") // Replaces -event_details- with the event's string
+```
+
+#### Setting multiple sections
+
+The `header.SetSections` allows you to set multiple sections in a single array.
+
+This is good when sending out multiple emails where no dynamic variation is required.
+
+This will reset any section key-pairs that have previously been set.
+
+```go
+header.SetSections(map[string]string{
+    "-event_details-":   "The event will be held tomorrow.",
+    "-event_open_time-": "'It will be open from 1am to 9pm.",
+})
+```
+
+<a name="filters"></a>
+## Filters
+
+Filters allow you to dynamically toggle features such as click tracking, blind copying and DKIM domain validation.
+
+#### Adding a single filter
+
+Adding a filter is easy with the `header.AddFilter` method.
+
+This method requires 3 values:
+- The filter's name
+- The parameter's name
+- The value
+
+```go
+header.AddFilter("dkim", "use_from", true)
+header.AddFilter("dkim", "domain", "example.com")
+```
+
+#### Adding pre-existing filters
+
+Filters with predetermined settings can also be added using the `header.SetFilter` method.
+
+```go
+filter := &Filter{
+    Settings: make(map[string]interface{}),
+}
+filter.Settings["enable"] = 1
+filter.Settings["text/plain"] = "You can haz footers!"
+header.SetFilter("footer", filter)
+```
+
+<a name="asm"></a>
+## Advanced Suppression Management (ASM)
+
+Advanced Suppression Management (or Unsubscribe Groups) are a good way of allowing recipients to unsubscribe from a specific set of emails.
+
+You can
+
+#### Setting the ASM group ID
+
+The `header.SetASMGroupID` method is a quick way to set the type of email that you are sending.
+
+All it requires is the ID of the ASM group, which can be found using the API.
+
+```go
+header.SetASMGroupID(42) // Sets the ASM ID to 42
+```
+
+<a name="send-at"></a>
+## Send At
+
+Scheduling the time of your email campaign can be done using a collection of quick and easy methods.
+
+#### Adding a single 'send at' date
+
+The `header.AddSendEachAt` method is a good way to add the time to send at.
+
+This method requires a unix timestamp as the input.
+
+```go
+header.AddSendEachAt(1508694645)
+```
+
+#### Setting multiple 'send at' date
+
+The `header.SetSendEachAt` method is useful for setting an array of times that recipients have their emails sent.
+
+This method requires an array of unix timestamps as the input.
+
+```go
+header.SetSendEachAt([]int64{
+    1508694645,
+    1508694835,
+})
+```
+
+#### Setting a single date to send all emails
+
+The `header.SetSendAt` method is useful for setting a single time that all emails in the collection will be sent.
+
+This method requires a unix timestamp as the input.
+
+```go
+header.SetSendAt(1508694645)
+```
+
+<a name="batches"></a>
+## Batches
+
+Batches are a great way to group a collection of scheduled items for sending. It allows you to cancel scheduled emails, and provides more control over the emails.
+
+The batch ID can be set using the `header.AddBatchId` method. You must have generated the batch ID first through the API.
+
+```go
+header.AddBatchId("HkJ5yLYULb7Rj8GKSx7u025ouWVlMgAi") // Adds a previously generated batch ID to the emails
+```
+
+<a name="ip-pools"></a>
+## IP Pools
+
+IP Pools allow you to group SendGrid IP addresses together. For example, if you have a set of marketing IPs, you can assign them a pool ID of `marketing`.
+
+The IP Pool name can be set using the `header.SetIpPool` method. You must have generated the IP Pool first through the API.
+
+```go
+header.SetIpPool("marketing") // Sets the IP Pool to be the marketing collection of IPs
+```
+
+
+<a name="retrieving-data"></a>
+#### Retrieving data as a JSON string
+
+The `header.JSONString` method allows the data from the header instance to be exported as a JSON string.
+
+```go
+headerString, _ := header.JSONString()
+fmt.Println(headerString)
+
+// {"to":["[email protected]"],"sub":{"key":["value"]},"section":{"section":"value"},"category":["category"],"unique_args":{"key":"value"},"filters":{"filter":{"settings":{"setting":"value"}}},"asm_group_id":1,"send_at":1428611024,"ip_pool":"testPool"}
+```