Added new contract templates (#31)

docker/code-templates/nodejs/file-contract/src/_projname_.js

@@ -0,0 +1,98 @@
+const fs = require('fs');
+const bson = require('bson');
+
+export class _projname_ {
+    sendOutput; // This function must be wired up by the caller.
+
+    async handleRequest(user, msg, isReadOnly) {
+
+        // This sample application defines simple file operations.
+        // It's up to the application to decide the structure and contents of messages.
+
+        if (msg.type == "upload") {
+            // Check already exist.
+            if (fs.existsSync(msg.fileName)) {
+                await user.send(bson.serialize({
+                    type: "uploadResult",
+                    status: "already_exists",
+                    fileName: msg.fileName
+                }));
+            }
+            // Error is too large.
+            else if (msg.content.length > 10 * 1024 * 1024) { // 10MB
+                await user.send(bson.serialize({
+                    type: "uploadResult",
+                    status: "too_large",
+                    fileName: msg.fileName
+                }));
+            }
+            else {
+                // Do not write in read only mode.
+                if (!isReadOnly) {
+                    // Save the file.
+                    fs.writeFileSync(msg.fileName, msg.content.buffer);
+
+                    await user.send(bson.serialize({
+                        type: "uploadResult",
+                        status: "ok",
+                        fileName: msg.fileName
+                    }));
+                }
+                else {
+                    await this.sendOutput(user, {
+                        type: "uploadResult",
+                        status: "error",
+                        error: 'Write is not supported in readonly mode'
+                    })
+                }
+            }
+        }
+        else if (msg.type == "delete") {
+            // Delete if exist.
+            if (fs.existsSync(msg.fileName)) {
+                // Do not delete in read only mode.
+                if (!isReadOnly) {
+                    fs.unlinkSync(msg.fileName);
+                    await user.send(bson.serialize({
+                        type: "deleteResult",
+                        status: "ok",
+                        fileName: msg.fileName
+                    }));
+                }
+                else {
+                    await this.sendOutput(user, {
+                        type: "deleteResult",
+                        status: "error",
+                        error: 'Delete is not supported in readonly mode'
+                    })
+                }
+            }
+            else {
+                await user.send(bson.serialize({
+                    type: "deleteResult",
+                    status: "not_found",
+                    fileName: msg.fileName
+                }));
+            }
+        }
+        // Send file if exist.
+        else if (msg.type == "download") {
+            if (fs.existsSync(msg.fileName)) {
+                const fileContent = fs.readFileSync(msg.fileName);
+                await user.send(bson.serialize({
+                    type: "downloadResult",
+                    status: "ok",
+                    fileName: msg.fileName,
+                    content: fileContent
+                }));
+            }
+            else {
+                await user.send(bson.serialize({
+                    type: "downloadResult",
+                    status: "not_found",
+                    fileName: msg.fileName
+                }));
+            }
+        }
+    }
+}

docker/code-templates/nodejs/file-contract/src/contract.js

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+const HotPocket = require('hotpocket-nodejs-contract');
+const bson = require('bson');
+const { _projname_ } = require('./_projname_');
+
+// HotPocket smart contract is defined as a function which takes the HotPocket contract context as an argument.
+// This function gets invoked every consensus round and whenever a user sends a out-of-concensus read-request.
+async function contract(ctx) {
+
+    // Create our application logic component.
+    // This pattern allows us to test the application logic independently of HotPocket.
+    const app = new _projname_();
+
+    // Wire-up output emissions from the application before we pass user inputs to it.
+    app.sendOutput = async (user, output) => {
+        await user.send(output)
+    }
+
+    // In 'readonly' mode, nothing our contract does will get persisted on the ledger. The benefit is
+    // readonly messages gets processed much faster due to not being subjected to consensus.
+    // We should only use readonly mode for returning/replying data for the requesting user.
+    //
+    // In consensus mode (NOT read-only), we can do anything like persisting to data storage and/or
+    // sending data to any connected user at the time. Everything will get subjected to consensus so
+    // there is a time-penalty.
+    const isReadOnly = ctx.readonly;
+
+    // Process user inputs.
+    // Loop through list of users who have sent us inputs.
+    for (const user of ctx.users.list()) {
+
+        // Loop through inputs sent by each user.
+        for (const input of user.inputs) {
+
+            // Read the data buffer sent by user (this can be any kind of data like string, json or binary data).
+            const buf = await ctx.users.read(input);
+
+            // Let's assume all data buffers for this contract are binary.
+            // In real-world apps, we need to gracefully filter out invalid data formats for our contract.
+            const msg = bson.deserialize(buf);
+
+            // Pass the JSON message to our application logic component.
+            await app.handleRequest(user, msg, isReadOnly);
+        }
+    }
+}
+
+const hpc = new HotPocket.Contract();
+hpc.init(contract);