refator: optimise regex parse, and update docs

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mdbook-embedify"
-version = "0.0.2"
+version = "0.1.0"
 edition = "2021"
 license = "MIT"
 readme = "README.md"

README.md

@@ -6,7 +6,7 @@ This is a [mdbook](https://rust-lang.github.io/mdBook) preprocessor plugin that
 
 ## 1. Installation
 
-First, you need to install mdbook-embedify to your computer.You can install it from crates.io using cargo.
+First, you need to install mdbook-embedify to your computer. You can install it from crates.io using cargo.
 
 ```sh
 cargo install mdbook-embedify

docs/index.html

@@ -26,7 +26,7 @@ <h1>Mdbook Embedify</h1>
         <h2>1. Installation</h2>
 
         <p>
-          First, you need to install mdbook-embedify to your computer.You can install it from crates.io using cargo.
+          First, you need to install mdbook-embedify to your computer. You can install it from crates.io using cargo.
         </p>
 
         <pre><code>cargo install mdbook-embedify</code></pre>

src/utils.rs

@@ -35,10 +35,17 @@ pub fn render_template(app: &str, placeholders: &[(String, String)]) -> String {
     let mut result = template.to_string();
     // replace the key with the value
     for (key, value) in placeholders {
-        // replace {key} or {key|default} with value
-        let pattern = format!(r"\{{{}\|?[^}}]*}}", key);
-        let re = Regex::new(&pattern).unwrap();
-        result = re.replace_all(&result, value).to_string();
+        // replace {key} with value
+        let re = Regex::new(&format!(r"\{{{}}}", key)).unwrap();
+        let replaced_result = re.replace_all(&result, value).to_string();
+        // replacement was successful
+        if replaced_result != result {
+            result = replaced_result;
+        } else {
+            //replacement does not success, try replace {key|default} with value
+            let re = Regex::new(&format!(r"\{{{}\|[^}}]*}}", key)).unwrap();
+            result = re.replace_all(&result, value).to_string();
+        }
     }
     // check if there are any placeholders left, this makes the process faster
     if result.contains('{') && result.contains('}') {