Added examples of extending Augeas object

2 files changed, 94 insertions, 0 deletions

diff --git a/examples/extending-augeas/aug-fileErrorMsg-usage.js b/examples/extending-augeas/aug-fileErrorMsg-usage.js
new file mode 100644
index 0000000..9e5b800
--- /dev/null
+++ b/examples/extending-augeas/aug-fileErrorMsg-usage.js
@@ -0,0 +1,21 @@
+var libaugeas = require('./aug-fileErrorMsg.js');
+
+
+// should give an error if running unprivileged:
+var testfile = '/etc/sudoers';
+
+
+// Creating Augeas asynchronously:
+libaugeas.createAugeas(function(aug) {
+    console.log(aug.fileErrorMsg(testfile));
+    console.log(aug.dumpFileErrors());
+});
+
+/* Example output:
+/etc/sudoers: Permission denied
+[ '/etc/mke2fs.conf:3:0: Get did not match entire input',
+  '/etc/host.conf:15:0: Iterated lens matched less than it should',
+  '/etc/securetty: Permission denied',
+  '/etc/sysctl.conf: Permission denied',
+  '/etc/sudoers: Permission denied' ]
+*/ 
diff --git a/examples/extending-augeas/aug-fileErrorMsg.js b/examples/extending-augeas/aug-fileErrorMsg.js
new file mode 100644
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+++ b/examples/extending-augeas/aug-fileErrorMsg.js
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+var libaugeas = require('../../build/Release/libaugeas');
+
+/*
+ * This modules overrides function createAugeas() from libaugeas,
+ * so that created Augeas object has two additional functions:
+ * fileErrorMsg(fname) and dumpFileErrors().
+ */
+
+
+
+// Error message formatter, sample return value:
+// "/etc/mke2fs.conf:3:0: Get did not match entire input"
+function file_error(fname) {
+    var aug = this;
+    var base = "/augeas/files" + fname + "/error";
+    var msg = aug.get(base + "/message");
+    var line = aug.get(base + "/line");
+    var col = aug.get(base + "/char");
+
+    var ret = undefined;
+
+    if (aug.nmatch(base)) {
+        ret = fname;
+        if (line)
+            ret += ":" + line;
+        if (col)
+            ret += ":" + col;
+
+        if (msg)
+            ret += ": " + msg;
+        else
+            ret += ": unknown error";
+    }
+    
+    return ret;
+}
+
+// Returns an array of error messages for every file with error:
+function dump_file_error() {
+    var aug = this;
+
+    var files_with_errors =
+        aug.match(
+                '/augeas/files/*/*[error]'
+        ).map(function(s){
+            return s.substr(13); // cutoff /augeas/files: 13 = strlen(/augeas/files)
+         });
+
+    var res = 
+        files_with_errors.map(function(fname){
+            return aug.fileErrorMsg(fname);
+        });
+
+    return res;
+}
+
+function createAugeas(cb) {
+    if (undefined == cb) {
+        var aug = libaugeas.createAugeas();
+        aug.fileErrorMsg = file_error;
+        aug.dumpFileErrors = dump_file_error;
+        return aug;
+    } else {
+        libaugeas.createAugeas(function(aug) {
+            aug.fileErrorMsg = file_error;
+            aug.dumpFileErrors = dump_file_error;
+            cb(aug);
+        })
+    }
+}
+
+exports.createAugeas = createAugeas;
+