download working (#2230)

Co-authored-by: burnettk <burnettk@users.noreply.github.com>

spiffworkflow-frontend/src/components/ProcessModelFileList.tsx

@@ -15,6 +15,8 @@ import { PureAbility } from '@casl/ability';
 import ButtonWithConfirmation from './ButtonWithConfirmation';
 import ProcessModelTestRun from './ProcessModelTestRun';
 import { ProcessFile } from '../interfaces';
+import HttpService from '../services/HttpService';
+import useAPIError from '../hooks/UseApiError';
 
 interface ProcessModelFileListProps {
   processModel: any;
@@ -35,6 +37,7 @@ export default function ProcessModelFileList({
   onSetPrimaryFile,
   isTestCaseFile,
 }: ProcessModelFileListProps) {
+  const { addError, removeError } = useAPIError();
   const profileModelFileEditUrl = (processModelFile: ProcessFile) => {
     if (processModel) {
       if (processModelFile.name.match(/\.(dmn|bpmn)$/)) {
@@ -47,6 +50,40 @@ export default function ProcessModelFileList({
     return null;
   };
 
+  const handleProcessModelFileResult = (processModelFile: ProcessFile) => {
+    if (
+      !('file_contents' in processModelFile) ||
+      processModelFile.file_contents === undefined
+    ) {
+      addError({
+        message: `Could not file file contents for file: ${processModelFile.name}`,
+      });
+      return;
+    }
+    let contentType = 'application/xml';
+    if (processModelFile.type === 'json') {
+      contentType = 'application/json';
+    }
+    const element = document.createElement('a');
+    const file = new Blob([processModelFile.file_contents], {
+      type: contentType,
+    });
+    const downloadFileName = processModelFile.name;
+    element.href = URL.createObjectURL(file);
+    element.download = downloadFileName;
+    document.body.appendChild(element);
+    element.click();
+  };
+
+  const downloadFile = (fileName: string) => {
+    removeError();
+    const processModelPath = `process-models/${modifiedProcessModelId}`;
+    HttpService.makeCallToBackend({
+      path: `/${processModelPath}/files/${fileName}`,
+      successCallback: handleProcessModelFileResult,
+    });
+  };
+
   const renderButtonElements = (
     processModelFile: ProcessFile,
     isPrimaryBpmnFile: boolean,
@@ -80,12 +117,7 @@ export default function ProcessModelFileList({
           iconDescription="Download File"
           hasIconOnly
           size="lg"
-          onClick={() =>
-            window.open(
-              `/${targetUris.processModelFilePath}/${processModelFile.name}`,
-              '_blank',
-            )
-          }
+          onClick={() => downloadFile(processModelFile.name)}
         />
       </Can>,
     );