hasMetadata

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Synopsis

hasMetadata [-asList] [-channelType string] [-endIndex string] [-ignoreDefault] [-index string] [-indexType string] [-memberName string] [-startIndex string] [-streamName string]

hasMetadata is NOT undoable, NOT queryable, and NOT editable.

This command is used to query for the presence of metadata elements on a node or components. The command works at all levels of metadata presence, from the existence of any metadata at all on a node right down to the presence of metadata values set on a particular metadata Stream index. Filter Flags

• channelType - Only look for metadata on one particular Channel type
• streamName - Only look for metadata on one particular named Stream. When used in conjunction with channelType then ignore Streams with a matching name but a different Channel type
• index - Only look for metadata on one or more specific Index values of a Stream. Requires use of the streamName flag. Does not require the indexType flag as that will be inferred by the streamName.
• startIndex/endIndex - Same as index but using an entire range of Index values rather than a single one
• indexType - Only look for metadata using a particular Index type. Can have its scope narrowed by other filter flags as well.
• ignoreDefault - Treat any metadata that still has the default value (e.g. 0 for numerics, "" for strings) the same as metadata that isn't present. This means that any metadata with default values will not be reported. It is useful for quickly finding values that you have changed. When this flag is set you can also use the memberName filter to narrow down the check to a particular member of the metadata Structure. Without that filter it will only skip over metadata where every member of the Structure has a non-default value.
• memberName - Only look at one particular Member in the metadata in a Structure. Only used when checking for non-default values as existence is based on the entire Structure, not any particular Member.

• normal mode - Return True for every specified location containing metadata. This combines with the filter flags as follows:
  • no flag - True if there is any metadata at all on the node
  • channelType - True if there is any metadata at all on the Channel associated with the given Channel type
  • streamName - True if there is any metadata at all on the Stream with the given name
  • index/startIndex/endIndex - An array of booleans ordered the same as the natural ordering of the Index values (i.e. specifying index 3, 2, and 4 in that order will still return booleans in the order for indices 2,3,4) where True means that there is metadata assigned at that Index. This form is better suited with the asList modification since with that variation it is easier to tell exactly which indices have the metadata.
• asList - Adding this flag switches the return values from a single boolean or array of booleans to an array of strings indicating exactly which metadata elements have values. The return values of the command are changed to be the following:
  • no flag - List of Channel types with metadata
  • channelType - List of Stream names in the Channel with metadata
  • streamName - List of Index values on the Stream with metadata
  • index/startIndex/endIndex - List of Index values with metadata, restricted to the set of specified Index values.

Return value

Keywords

Related

Flags

Long name (short name)	Argument types	Properties
-memberName(-mn)	string
Name of the Structure member being checked. The names of the members are set up in the Structure definition, either through the description passed in through the "dataStructure" command or via the API used to create that Structure. As the assignment of metadata is on a per-structure basis this flag only needs to be specified when querying for non-default values. If you query for non-default values and omit this flag then it checks that any of the members have a non-default value.
-asList(-al)
Use this flag when you want to return string values indicating where the metadata lives rather than boolean values. See the command description for more details on what this flag will return.
-ignoreDefault(-id)
Use this flag when you want to skip over any metadata that has only default values. i.e. the metadata may exist but it hasn't had a new value set yet (non-zero for numerics, non-empty strings, etc.) See the command description for more details on how this flag filters the search.
-channelType(-cht)	string
Filter the metadata selection to only recognize metadata belonging to the specified channel type (e.g. "vertex"). This flag is ignored if the components on the selection list are being used to specify the metadata of interest. In query mode, this flag can accept a value.
-endIndex(-eix)	string
The metadata is stored in a Stream, which is an indexed list. If you have mesh components selected then the metadata indices are implicit in the list of selected components. If you select only the node then this flag may be used in conjunction with the startIndex flag to specify a range of indices from which to retrieve the metadata. It is an error to have the value of startIndex be greater than that of endIndex. See also the index flag for an alternate way to specify multiple indices. This flag can only be used on index types that support a range (e.g. integer values - it makes no sense to request a range between two strings) In query mode, this flag can accept a value.
-index(-idx)	string
In the typical case metadata is indexed using a simple integer value. Certain types of data may use other index types. e.g. a "vertexFace" component will use a "pair" index type, which is two integer values; one for the face ID of the component and the second for the vertex ID. The index flag takes a string, formatted in the way the specified indexType requires. All uses of the index flag have the same indexType. If the type was not specified it is assumed to be a simple integer value. In query mode, this flag can accept a value.
-indexType(-idt)	string
Name of the index type the new Channel should be using. If not specified this defaults to a simple integer index. Of the native types only a mesh "vertexFace" channel is different, using a "pair" index type. In query mode, this flag can accept a value.
-startIndex(-six)	string
The metadata is stored in a Stream, which is an indexed list. If you have mesh components selected then the metadata indices are implicit in the list of selected components. If you select only the node then this flag may be used in conjunction with the endIndex flag to specify a range of indices from which to retrieve the metadata. It is an error to have the value of startIndex be greater than that of endIndex. See also the index flag for an alternate way to specify multiple indices. This flag can only be used on index types that support a range (e.g. integer values - it makes no sense to request a range between two strings) In query mode, this flag can accept a value.
-streamName(-stn)	string
Name of the metadata Stream. Depending on context it could be the name of a Stream to be created, or the name of the Stream to pass through the filter. In query mode, this flag can accept a value.

Flag can appear in Create mode of command	Flag can appear in Edit mode of command
Flag can appear in Query mode of command	Flag can be used more than once in a command.

MEL examples

polyPlane -n smcPlane -ch off;
// Result: smcPlane //
// Create structures
dataStructure -format "raw" -asString "name=idStructure:int32=ID";
// Result: idStructure //
dataStructure -format "raw" -asString "name=keyValueStructure:string=value";
// Result: keyValueStructure //
// Apply structures to plane
select -r smcPlaneShape;
addMetadata -structure "idStructure" -streamName "idStream" -channelType "vertex";
addMetadata -structure "keyValueStructure" -streamName "keyValueStream" -channelType "key" -indexType "string";
// Apply the metadata values to three of the components by selection
select -r smcPlaneShape.vtx[8:10];
editMetadata -streamName "idStream" -memberName "ID" -value 7;
// Result: 3 //
// Verify existence of the three newly set metadata values at the node level
select -r smcPlaneShape;
hasMetadata;
// Result: 1 //
// Verify existence of the three newly set metadata values at the Channel level
hasMetadata -channelType "vertex";
// Result: 1 //
hasMetadata -channelType "edge";
// Result: 0 //
// Verify existence of the three newly set metadata values at the Stream level
hasMetadata -channelType "vertex" -streamName "idStream";
// Result: 1 //
hasMetadata -channelType "edge" -streamName "someOtherStream";
// Result: 0 //
// Verify existence of the three newly set metadata values at the Index level
hasMetadata -channelType "vertex" -streamName "idStream" -index "8" -index "9";
// Result: 1 1 //
hasMetadata -channelType "vertex" -streamName "idStream" -index "8" -index "9999";
// Result: 1 0 //
// Verify existence of default metadata values at the Index level. Since the
// index range was established to be 0-17 by assignment and the Stream
// defaults to returning default values for unassigned indices the lower index
// values "0" and "1" do have metadata (as default values) but the higher one
// "9999" in the above example does not.
hasMetadata -channelType "vertex" -streamName "idStream" -index "0" -index "1";
// Result: 1 1 //
// Verify non-existence of non-default metadata values at the Index level
hasMetadata -ignoreDefault -channelType "edge" -streamName "idStream" -memberName "ID" -index "0" -index "1";
// Result: 0 0 //
// Get the list of Index values with assigned metadata on the object
select -r smcPlaneShape.vtx[8:20];
hasMetadata -channelType "vertex" -streamName "idStream" -asList;
// Result: 8 9 10 //
// Set metadata values using the complex index type "string"
editMetadata -streamName "keyValueStream" -memberName "value" -stringValue "Starry Night" -indexType "string" -index "Title";
editMetadata -streamName "keyValueStream" -memberName "value" -stringValue "Vincent Van Gogh" -indexType "string" -index "Artist";
// Verify existence of the complex index data
hasMetadata -streamName "keyValueStream" -memberName "value" -channelType "key" -index "Title" -index "Artist" -indexType "string" -asList;
// Result: "Artist" "Title" //