Add new batchFIle template tag that replaces itself by a file's _cont…

…ents_ on request send

main.js

@@ -3,8 +3,37 @@ import { createRoot } from 'react-dom/client';
 
 import BatchDialog from './components/BatchDialog';
 import BatchDialogSettings from './components/BatchDialogSettings';
-import { templateTags } from './tags';
+import { templateTags, MAGIC_FILE_FIELD_PREFIX } from './tags';
 
+
+module.exports.requestHooks = [
+  /*
+    Intercepts outgoing requests, and then:
+    1. Finds any fields in the req body whose value starts with %INSOMNIA_PLUGIN_BATCH_REQUESTS%
+    2. Force-converts them into File fields (they'll be coming in as Text fields)
+    3. The file that will be sent on that field will be the rest of the text value 
+       (i.e. everything that came _after_ %INSOMNIA_PLUGIN_BATCH_REQUESTS%)
+    
+    This hook works in concert with the Batch (File) template tag (see tags.js), 
+    which generates values with the requisite magic prefix.
+  */
+  context => {
+    const body = context.request.getBody();
+    if(body.mimeType === "multipart/form-data" && body.params) {
+      for(let param of body.params) {
+        if(param.value.startsWith(MAGIC_FILE_FIELD_PREFIX)) {
+          param.type = "file"
+          param.fileName = param.value.replace(MAGIC_FILE_FIELD_PREFIX, "");
+        }
+      }
+    }
+    context.request.setBody(body);
+  }
+];
+
+
+// Provides the context menu action that appears when opening the dropdown menu
+// for a request, which is the main entrypoint to the plugin's functionality
 module.exports.requestActions = [{
   label: 'Batch Requests',
   icon: 'fa-repeat',

tags.js

@@ -1,3 +1,5 @@
+export const MAGIC_FILE_FIELD_PREFIX = "%INSOMNIA_PLUGIN_BATCH_REQUESTS%"
+
 export const templateTags = [{
     name: 'batchVariable',
     displayName: 'Batch',
@@ -32,4 +34,48 @@ export const templateTags = [{
             return sample;
         }
     },
+},
+/*
+    When set on a Text field in a form body, this template tag will replace itself with the value
+    "%INSOMNIA_PLUGIN_BATCH_REQUESTS%<field in CSV column>"
+    This will be set by Insomnia as the (text) value of the field.
+    Then, as the request is going out, it'll be intercepted by a Request hook (see main.js),
+    which will strip the prefix and force the field to be interpreted as a File, rather than pure text,
+    as if a user had selected a file to begin with, in the Insomnia UI
+*/
+{
+    name: 'batchFile',
+    displayName: 'Batch (File)',
+    liveDisplayName: ([colName, sample]) => (colName.value ? `CSV[${colName.value}] as File: ${sample.value}` : 'Batch'),
+    description: 'Placeholder for the Batch Requests plugin',
+    args: [
+        {
+            displayName: 'Name',
+            description: 'Ensure that this value matches the name of a column in your CSV file',
+            type: 'string',
+            validate: (val) => (val ? '' : 'Enter a column name!'),
+        },
+        {
+            displayName: 'Sample value',
+            description: 'This value will be used when sending the request manually (outside of Batch Requests)',
+            type: 'string'
+        }
+    ],
+    async run(context, name, sample) {
+        // context.renderPurpose is set to 'send' when actually sending the request
+        if(context.renderPurpose === 'send') {
+            const extraData = context.context.getExtraInfo("batchExtraData")
+            if(extraData) {
+                console.debug('[store.get]', extraData);
+                // Magic marker so we can later (in a request hook) identify these fields and mangle them
+                return MAGIC_FILE_FIELD_PREFIX + JSON.parse(extraData)[name];
+            } else {
+                console.error(`Cannot find column ${name} on request extra data! Falling back to sample value.`);
+                return MAGIC_FILE_FIELD_PREFIX + sample;
+            }
+        } else {
+            // context.renderPurpose is undefined when previewing the template tag's value
+            return "[File contents of " + sample + "]";
+        }
+    },
 }]