Metadata

This group covers methods that read, normalize, and copy structured data associated with a media node — including its metadata object, file properties, and display name.

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metadata()

Reads and normalizes the metadata field from the node's model, then flattens key fields directly onto the model for easier access.

What it does

metadata()
  │
  ├── Read model's metadata field (may be a plain object or a JSON string)
  │
  ├── If metadata is a string
  │     → JSON.parse(metadata)
  │     → if parse fails → return {}
  │
  ├── Extract: { md5Hash, dataType }
  ├── Flatten onto model: mset({ md5Hash, dataType })
  │
  └── Return the parsed metadata object

Why it parses strings

Depending on the data source, metadata may arrive from the server as a JSON string rather than a parsed object. metadata() handles both shapes transparently so callers never need to check.

// Server sends:  metadata: '{"md5Hash":"abc123","dataType":"diagram.state"}'
// After calling metadata():
this.mget("md5Hash"); // → "abc123"
this.mget("dataType"); // → "diagram.state"

When it's called

Called automatically at the end of initData() — you rarely need to call it directly. Override it in a subclass if you need to extract additional fields from the metadata object:

metadata() {
  const md = super.metadata();
  const { customField } = md;
  this.mset({ customField });
  return md;
}

Return value

Returns the parsed metadata object (plain {}). Returns an empty object {} if the field is missing or unparseable.

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copyPropertiesFrom(src)

Copies a predefined set of file system properties from another media node (src) onto this node's model.

Signature

Param	Type	Description
src	MFS node	The source node to copy properties from

Properties copied

Only non-null values are copied — properties missing on src are skipped:

area          actual_home_id    ctime         ext
filename      filepath          filetype      filesize
geometry      home_id           hub_id        isalink
md5Hash       metadata          mtime         nid
origin        ownpath           pid           privilege
status

When to use

Use copyPropertiesFrom when you need to transfer a node's identity and file attributes to another node — for example when cloning, replacing, or initializing a placeholder node from a real one:

const placeholder = new pseudo_media();
placeholder.copyPropertiesFrom(realMediaNode);

Note: Only properties with truthy values are copied. Falsy values (null, 0, "", undefined) on the source are not transferred, preserving any existing values on the target.

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fullname()

Returns the complete filename with its extension as a single string.

Signature

fullname(); // → "document.pdf"

What it does

fullname() {
  return `${this.mget(_a.filename)}.${this.mget(_a.ext)}`;
}

Combines the filename and ext fields from the model. This is a simple convenience method — use it whenever you need the full file name with extension for display, download, or saving purposes.

Example

const name = this.fullname();
// → "quarterly-report.xlsx"

// Common use in download flow
const filename = this.fullname();
this.fetchFile({ url, download: filename });

Note: If filename already contains the extension (e.g. "report.pdf"), calling fullname() will duplicate it → "report.pdf.pdf". Use mget(_a.filename) directly in that case, or check mget(_a.ext) before calling.

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Method Relationships

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Quick Reference

Method	Input	Output	When to call
metadata()	—	Parsed metadata {}	Auto via initData(), override to extract custom fields
copyPropertiesFrom(src)	Source MFS node	—	When cloning or initializing a node from another
fullname()	—	"filename.ext" string	When the full filename with extension is needed