Touched up README

README.md

@@ -14,6 +14,8 @@ go get git.streifling.com/jason/atom@latest
 
 ## Usage
 
+### Basic Feed
+
 This library provides convenient functions to safely create, extend and delete
 elements and attributes of Atom feeds. It also provides checks for all
 constructs' adherence to RFC4287.
@@ -48,7 +50,7 @@ func main() {
     }
     feed.AddEntry(entry)
 
- feedString, err := feed.ToXML("utf-8")
+    feedString, err := feed.ToXML("UTF-8")
     if err != nil {
         log.Fatalln(err)
     }
@@ -68,6 +70,7 @@ import (
     "time"
 
     "git.streifling.com/jason/atom"
+    "github.com/google/uuid"
 )
 
 func main() {
@@ -78,7 +81,7 @@ func main() {
             Type: "text",
             Text: "Example Feed",
         },
-  ID:      &atom.ID{URI: "urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6"},
+        ID:      &atom.ID{URI: fmt.Sprint("urn:uuid:", uuid.New())},
         Updated: &atom.Date{DateTime: atom.DateTime(now)},
         Authors: []*atom.Person{
             {
@@ -92,7 +95,7 @@ func main() {
                     Type: "text",
                     Text: "First Entry",
                 },
-    ID:      &atom.ID{URI: "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a"},
+                ID:      &atom.ID{URI: fmt.Sprint("urn:uuid:", uuid.New())},
                 Updated: &atom.Date{DateTime: atom.DateTime(now)},
                 Content: &atom.InlineTextContent{
                     Type: "text",
@@ -102,7 +105,7 @@ func main() {
         },
     }
 
- feedString, err := feed.ToXML("utf-8")
+    feedString, err := feed.ToXML("UTF-8")
     if err != nil {
         log.Fatalln(err)
     }
@@ -113,7 +116,7 @@ func main() {
 The output of both ways of using it is an RFC4287 compliant Atom feed.
 
 ```xml
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <feed xmlns="http://www.w3.org/2005/Atom">
     <author>
         <name>John Doe</name>
@@ -130,3 +133,109 @@ The output of both ways of using it is an RFC4287 compliant Atom feed.
     </entry>
 </feed>
 ```
+
+### Compliance and Error Checking
+
+All Atom constructs have their own ```construct.Check()``` method. It checks for
+compliance with RFC4287 and errors. This allows one to be certain that only
+compliant constructs are added to their respective parent construct. It also
+means that not the entire feed has to be checked every time a new construct is
+added. Instead one only checks the current construct and all of its
+sub-constructs with a single ```construct.Check()``` call.
+
+```go
+package main
+
+import (
+    "fmt"
+    "log"
+
+    "git.streifling.com/jason/atom"
+)
+
+func main() {
+    feed := atom.NewFeed("Example Feed")
+    if err := feed.Check(); err != nil {
+        log.Fatalln(err)
+    }
+
+    entry := atom.NewEntry("One")
+    entry.Content = atom.NewContent(atom.InlineText, "text", "Entry One")
+    entry.AddAuthor(atom.NewPerson("John Doe"))
+    if err := entry.Check(); err != nil {
+        log.Fatalln(err)
+    }
+    feed.AddEntry(entry)
+
+    feedString, err := feed.ToXML("UTF-8")
+    if err != nil {
+        log.Fatalln(err)
+    }
+    fmt.Println(feedString)
+}
+```
+
+### Adding and Deleting Items
+
+To add elements to any slice one calls the appropriate
+```someone.AddSomething(toBeAdded)``` method. It returns the item's index
+number. To delete the item one calls the Delete method.
+
+```go
+package main
+
+import (
+    "fmt"
+    "log"
+
+    "git.streifling.com/jason/atom"
+)
+
+func main() {
+    feed := atom.NewFeed("Feed")
+    if err := feed.Check(); err != nil {
+        log.Fatalln(err)
+    }
+
+    e1 := atom.NewEntry("One")
+    e1.Content = atom.NewContent(atom.InlineText, "text", "Entry One")
+    if err := e1.Check(); err != nil {
+        log.Fatalln(err)
+    }
+    i1 := feed.AddEntry(e1)
+
+    e2 := atom.NewEntry("Two")
+    e2.Content = atom.NewContent(atom.InlineText, "text", "Entry Two")
+    if err := e2.Check(); err != nil {
+        log.Fatalln(err)
+    }
+    feed.AddEntry(e2)
+
+    if err := feed.DeleteEntry(i1); err != nil {
+        log.Fatalln(err)
+    }
+
+    feedString, err := feed.ToXML("UTF-8")
+    if err != nil {
+        log.Fatalln(err)
+    }
+    fmt.Println(feedString)
+}
+```
+
+The output of this example looks like this. It only shows the second entry.
+
+```xml
+<?xml version="1.0" encoding="utf-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom">
+    <id>urn:uuid:ae89d343-b535-447d-ac14-4b80d3e02a2f</id>
+    <title type="text">Example Feed</title>
+    <updated>2024-10-20T14:57:02+02:00</updated>
+    <entry>
+        <content type="text">Entry Two</content>
+        <id>urn:uuid:620c6f73-ee1d-4c1e-be98-b0b1ad7a053f</id>
+        <title type="text">Two</title>
+        <updated>2024-10-20T14:57:02+02:00</updated>
+    </entry>
+</feed>
+```

atom.go

@@ -21,8 +21,8 @@ func addToSlice[C Countable](slice *[]C, countable C) int {
 	if *slice == nil {
 		*slice = make([]C, 0)
 	}
-	*slice = append(*slice, countable)
 
+	*slice = append(*slice, countable)
 	return len(*slice) - 1
 }