changeset 53:601a604c097a

new module with getStringValue
author drewp@bigasterisk.com
date Mon, 13 Jan 2020 00:06:36 -0800
parents 490f569bb0c9
children 6933336a8fae
files src/graph_queries.ts src/index.ts
diffstat 2 files changed, 19 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/graph_queries.ts	Mon Jan 13 00:06:36 2020 -0800
@@ -0,0 +1,18 @@
+import { N3Store, NamedNode } from "n3";
+
+export function getStringValue(
+  store: N3Store | undefined,
+  subj: NamedNode,
+  pred: NamedNode,
+  defaultValue: string = ""
+): string {
+  if (store === undefined) {
+    // this is so you can use the function before you have a graph
+    return "...";
+  }
+  const objs = store.getObjects(subj, pred, null);
+  if (objs.length == 0) {
+    return defaultValue;
+  }
+  return objs[0].value;
+}
--- a/src/index.ts	Thu Jan 09 00:34:05 2020 -0800
+++ b/src/index.ts	Mon Jan 13 00:06:36 2020 -0800
@@ -7,6 +7,7 @@
 import { StreamedGraphClient } from "./streamed_graph_client";
 
 import style from "./style.styl";
+export * from "./graph_queries";
 
 export interface VersionedGraph {
   version: number;