Added ability to do an export as CSV from the repeater list menu. Tec…

…hnically this addresses #1, but it's working.

RepeaterQTH/Pages/GetRepeaters.razor

@@ -16,7 +16,8 @@
 @using MongoDB.Bson.Serialization.Options
 
 
-<h1>Repeater Directory</h1>
+<div style="float: left"><h1>Repeater Directory</h1></div>
+<div style="float: right; margin-top: 20px"> <button @onclick="@DownloadText">Export</button></div>
 
 
 @if (repeaters == null)
@@ -26,9 +27,10 @@
 else
 {
     <RepeaterList repeaters=repeaters/>
-   
+
 }
 
+
 @code {
     [Parameter]  
     #nullable enable
@@ -86,5 +88,18 @@ else
 
     }
 
+    async Task DownloadText()
+    {
+        string data = "Callsign, RxFreq, TxFreq, Tone, Tone Type, State,  Location\n";
+        foreach (var repeater in repeaters)
+        {
+            data += repeater.CallSign + ", " + repeater.RxFreq + ", " + repeater.TxFreq + ", " +repeater.CTCSS+"," + repeater.Tone + ", " + repeater.State + ", "+repeater.LocationInfo + "\n";
+        }
+
+        byte[] file = System.Text.Encoding.UTF8.GetBytes(data);
+        var fileName = "rqth" + DateTime.Now.ToString("yyyyMMddHHmm")+".csv";
+        await jsRuntime.InvokeVoidAsync("BlazorDownloadFile", fileName, "text/csv", file);
+    }
+
 }
 

RepeaterQTH/Pages/_Host.cshtml

@@ -44,6 +44,7 @@
 <!--<script src="js/leafletBlazorInterops.js"></script>-->
 <script src="_content/BlazorLeaflet/js/leafletBlazorInterops.js"></script>
 <script src="_content/BrowserInterop/scripts.js"></script>
+<script src="js/download.js"></script>
 <script>
   window.getIpAddress = () => {
     return fetch('https://jsonip.com/')

RepeaterQTH/wwwroot/js/download.js

@@ -0,0 +1,46 @@
+function BlazorDownloadFile(filename, contentType, content) {
+    // Blazor marshall byte[] to a base64 string, so we first need to convert the string (content) to a Uint8Array to create the File
+    const data = base64DecToArr(content);
+
+    // Create the URL
+    const file = new File([data], filename, { type: contentType });
+    const exportUrl = URL.createObjectURL(file);
+
+    // Create the <a> element and click on it
+    const a = document.createElement("a");
+    document.body.appendChild(a);
+    a.href = exportUrl;
+    a.download = filename;
+    a.target = "_self";
+    a.click();
+
+    // We don't need to keep the url, let's release the memory
+    // On Safari it seems you need to comment this line... (please let me know if you know why)
+    URL.revokeObjectURL(exportUrl);
+}
+
+// Convert a base64 string to a Uint8Array. This is needed to create a blob object from the base64 string.
+// The code comes from: https://developer.mozilla.org/fr/docs/Web/API/WindowBase64/D%C3%A9coder_encoder_en_base64
+function b64ToUint6(nChr) {
+    return nChr > 64 && nChr < 91 ? nChr - 65 : nChr > 96 && nChr < 123 ? nChr - 71 : nChr > 47 && nChr < 58 ? nChr + 4 : nChr === 43 ? 62 : nChr === 47 ? 63 : 0;
+}
+
+function base64DecToArr(sBase64, nBlocksSize) {
+    var
+        sB64Enc = sBase64.replace(/[^A-Za-z0-9\+\/]/g, ""),
+        nInLen = sB64Enc.length,
+        nOutLen = nBlocksSize ? Math.ceil((nInLen * 3 + 1 >> 2) / nBlocksSize) * nBlocksSize : nInLen * 3 + 1 >> 2,
+        taBytes = new Uint8Array(nOutLen);
+
+    for (var nMod3, nMod4, nUint24 = 0, nOutIdx = 0, nInIdx = 0; nInIdx < nInLen; nInIdx++) {
+        nMod4 = nInIdx & 3;
+        nUint24 |= b64ToUint6(sB64Enc.charCodeAt(nInIdx)) << 18 - 6 * nMod4;
+        if (nMod4 === 3 || nInLen - nInIdx === 1) {
+            for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) {
+                taBytes[nOutIdx] = nUint24 >>> (16 >>> nMod3 & 24) & 255;
+            }
+            nUint24 = 0;
+        }
+    }
+    return taBytes;
+}