Add option for GET request for simple barcodes

templates/help.html

@@ -4,7 +4,12 @@
 {{ end }}
 
 {{ define "body" }}
-    <p>API Requests can be made by making a POST request to /generate</p>
+    <p>For simple textual QR, Aztec or DataMatrix codes, a GET request can be made as follows:</p>
+    <code>/generate?type=[qr|aztec|datamatrix]&text=[YOUR_TEXT]</code>
+    <p>Dimensions will default to 300x300, and ECC level to 2.</p>
+    <p>This is also the format for URL barcodes</p>
+
+    <p>For other barcode types and custom options, API Requests can be made by making a POST request to /generate</p>
 
     <p>The request body should be JSON similar to the below</p>
 
@@ -35,6 +40,7 @@
 
     <p>The response will be a PNG image</p>
 
+
     <h2>Formatted Barcodes</h2>
 
     <p>Formatted barcodes are under development, this API endpoint <code>/generate/format</code> will produce a QR, Aztec or Datamatrix barcode with one of the following formats:</p>
@@ -47,4 +53,5 @@
         <li>Phone Number</li>
     </ul>
     <p>Note that URLs have no special formatting and can be produced as plain text barcodes using the <code>/generate</code> endpoint</p>
+    <p>This endpoint is not yet available</p>
 {{ end }}

web/generate.route.go

@@ -2,6 +2,7 @@ package web
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"image"
 	"image/png"
@@ -12,18 +13,29 @@ import (
 	"github.com/boombuler/barcode"
 )
 
-// Generates a barcode from the data and options provided in the request body
+// Generates a barcode from the data and options provided in the request
 func generateBarcode(w http.ResponseWriter, r *http.Request) {
-	if r.Method != http.MethodPost {
-		http.Error(w, "Use a POST request for barcode generation", http.StatusMethodNotAllowed)
+
+	if r.Method != http.MethodPost && r.Method != http.MethodGet {
+		http.Error(w, "Use a POST or GET request for barcode generation. See the help page for more information", http.StatusMethodNotAllowed)
 		return
 	}
 
-	var req BarcodeRequest
-	err := json.NewDecoder(r.Body).Decode(&req)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
+	var req *BarcodeRequest
+	var err error
+
+	if r.Method == http.MethodGet {
+		req, err = generateFromGet(r)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+	} else {
+		err := json.NewDecoder(r.Body).Decode(&req)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
 	}
 
 	parameters := generation.Parameters{
@@ -66,3 +78,37 @@ func generateBarcode(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "Error streaming barcode", http.StatusInternalServerError)
 	}
 }
+
+func generateFromGet(r *http.Request) (*BarcodeRequest, error) {
+	//var parameters generation.Parameters
+	if r.Method == http.MethodGet {
+		validTypes := map[string]bool{
+			"qr":         true,
+			"aztec":      true,
+			"datamatrix": true,
+		}
+
+		typeParam := r.URL.Query().Get("type")
+		content := r.URL.Query().Get("text")
+
+		if typeParam == "" || content == "" {
+			return nil, errors.New("both 'type' and 'text' parameters are required")
+		}
+
+		if !validTypes[typeParam] {
+			return nil, errors.New("'type' must be 'qr', 'aztec', or 'datamatrix'")
+		}
+
+		barcodeReq := &BarcodeRequest{
+			BarcodeType: typeParam,
+			Width:       300,
+			Height:      300,
+			ECCLevel:    2,
+			Content:     content,
+		}
+
+		return barcodeReq, nil
+	} else {
+		return nil, errors.New("incorrect request type passed to function")
+	}
+}