Class GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>

GoDiagram®
v10.0.11
by Northwoods Software®

GraphLinksModels support links between nodes and grouping nodes and links into subgraphs. GraphLinksModels hold node data and link data in separate collections.

Inheritance

object

Model<TNodeData, TNodeKey, TSharedData>

GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>

Implements

IModel

Namespace: Northwoods.Go.Models

Assembly: Northwoods.GoDiagram.Avalonia.dll

Syntax

public class GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort> : Model<TNodeData, TNodeKey, TSharedData>, IModel where TNodeData : class, new() where TNodeKey : IEquatable<TNodeKey> where TLinkData : class, new() where TLinkKey : IEquatable<TLinkKey> where TPort : IEquatable<TPort>

Type Parameters

Name	Description
TNodeData
TNodeKey
TSharedData
TLinkData
TLinkKey
TPort

Remarks

Node data is normally represented in a Diagram by instances of Node, but they could be represented by simple Parts or by Groups. Link data should be represented by instances of Link.

Each link data object is assumed to have two values, one referring to the node that the link is coming from and one that the link is going to. The LinkFromKeyProperty property names the property on the link data whose value is the key of the "from" node. The LinkToKeyProperty property names the property on the link data whose value is the key of the "to" node. The default values for these properties are "From" and "To" respectively.

For example, one can define a graph consisting of two nodes with one link connecting them:

model.NodeDataSource = new List<MyNodeData> {
  new MyNodeData { Key = "Alpha" },
  new MyNodeData { Key = "Beta" }
};
model.LinkDataSource = new List<MyLinkData> {
  new MyLinkData { From = "Alpha", To = "Beta" }
};

If you want to have subgraphs in your diagram, where a group node contains some number of nodes and links, you need to declare that some node data actually represent groups, and you need to provide a reference from a member node data to its containing group node data. The NodeIsGroupProperty property names the property on a node data that is true if that node data represents a group. The NodeGroupKeyProperty property names the property on a node data whose value is the key of the containing group's node data. The default values for these properties are "IsGroup" and "Group" respectively.

For example, one can define a graph consisting of one group containing a subgraph of two nodes connected by a link, with a second link from that group to a third node that is not a member of that group:

model.NodeDataSource = new List<MyNodeData> {
  new MyNodeData { Key = "Group1", IsGroup = true },
  new MyNodeData { Key = "Alpha", Group = "Group1" },
  new MyNodeData { Key = "Beta", Group = "Group1" },
  new MyNodeData { Key = "Gamma" }
};
model.LinkDataSource = new List<MyLinkData> {
  new MyLinkData { From = "Alpha", To = "Beta" },
  new MyLinkData { From = "Group1", To = "Gamma" }
];

GraphLinksModels also support distinguishing the "port" element of a node to which a link can connect, at either end of the link. This identification is a string that names the "port" element in the node. However, you need to set the LinkFromPortIdProperty and/or LinkToPortIdProperty properties before the model is able to get the "port id" information from the link data.

For example, one can define a graph consisting of a "subtraction" node and two inputs and one output. The "subtraction" node has two distinct inputs called "subtrahend" and "minuend"; the output is called "difference".

model.LinkFromPortIdProperty = "FromPort";  // necessary to remember port ids
model.LinkToPortIdProperty = "ToPort";
model.NodeDataSource = new List<MyNodeData> {
  new MyNodeData { Key = 1, Constant = 5 },  // a constant input node
  new MyNodeData { Key = 2, Constant = 2 },  // another constant node
  new MyNodeData { Key = 3, Operation = "subtract" },
  new MyNodeData { Key = 4, Value = 3 }  // the output node
};
model.LinkDataSource = new List<MyLinkData> {
  new MyLinkData { From = 1, To = 3, ToPort = "subtrahend" },
  new MyLinkData { From = 2, To = 3, ToPort = "minuend" },
  new MyLinkData { From = 3, To = 4, FromPort = "difference" }
};

In this case links connected to node 3 (which is the subtraction operation) are distinguished by port id. The connections to the other nodes do not have any port identification, presumably because there is only one port on those nodes, representing the node value.

Each link data object is assumed to have a unique key value. The LinkKeyProperty property names the property on the link data whose value is the unique key for that link data object. The default value for this property is "Key". You should not have a TwoWay data binding on the link key property, because that might cause the property value to be set to a duplicate key value.

If the key is undefined, or if there are duplicate key values, the model will automatically try to assign a new unique key value.

Just as with the assignment of node keys, you can customize the assignment of link keys by setting MakeUniqueLinkKeyFunction to a function that returns a unique identifier.

This model does not support the modification of whether a node data object is a group.

This model cannot detect the modification of the LinkDataSource array or the modification of any link data object. If you want to add or remove link data from the LinkDataSource, call the AddLinkData(TLinkData) or RemoveLinkData(TLinkData) methods. If you want to modify the node a link connects to, call the SetFromKeyForLinkData(TLinkData, TNodeKey) and/or SetToKeyForLinkData(TLinkData, TNodeKey) methods. If you want to change the membership of a node data in a group, call the SetGroupKeyForNodeData(TNodeData, TNodeKey) method.

Constructors

GraphLinksModel(GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>)

Constructs a copy of a given GraphLinksModel, without copying the data.

Declaration

protected GraphLinksModel(GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort> model)

Parameters

Type	Name	Description
GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>	model

GraphLinksModel(IEnumerable<TNodeData>, IEnumerable<TLinkData>)

Constructs an empty GraphLinksModel unless one provides arguments as the initial data collection values for the NodeDataSource and LinkDataSource properties.

Declaration

public GraphLinksModel(IEnumerable<TNodeData> nodedatasource = null, IEnumerable<TLinkData> linkdatasource = null)

Parameters

Type	Name	Description
IEnumerable<TNodeData>	nodedatasource	an optional collection containing objects to be represented by Nodes.
IEnumerable<TLinkData>	linkdatasource	an optional collection containing objects to be represented by Links.

Properties

ArchetypeNodeData

Gets or sets a data object that will be copied and added to the model as a new node data each time there is a link reference (either the "to" or the "from" of a link data) to a node key that does not yet exist in the model.

Declaration

public TNodeData ArchetypeNodeData { get; set; }

Property Value

Type	Description
TNodeData

Remarks

The default value is null -- node data is not automatically copied and added to the model when there is an unresolved reference in a link data. When adding or modifying a link data if there is a "from" or "to" key value for which FindNodeDataForKey(TNodeKey) returns null, it will call CopyNodeData(TNodeData) on this property value and AddNodeData(TNodeData) on the result.

CopyLinkDataFunction

Gets or sets a function that makes a copy of a link data object.

Declaration

public Func<TLinkData, GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>, TLinkData> CopyLinkDataFunction { get; set; }

Property Value

Type	Description
Func<TLinkData, GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>, TLinkData>

Remarks

You may need to set this property in order to ensure that a copied Link is bound to data that does not share certain data structures between the original link data and the copied link data. This property value may be null in order to cause CopyLinkData(TLinkData) to make a shallow copy of an Object. The default value is null.

LinkCategoryProperty

Gets or sets the name of the data property that returns a string naming that data's category.

Declaration

public string LinkCategoryProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the name "Category", meaning that it expects the data to have a property named "Category" if it cares to name the category for the Link. This is used by the diagram to distinguish between different kinds of links. The name must not be null. If the value is an empty string, GetCategoryForLinkData(TLinkData) will return an empty string for all link data objects.

If you want to set this property you must do so before using the model, and especially before you assign Model.

LinkDataSource

Gets or sets the collection of link data objects that correspond to Links in the Diagram.

Declaration

public IEnumerable<TLinkData> LinkDataSource { get; set; }

Property Value

Type	Description
IEnumerable<TLinkData>

Remarks

The initial value is an empty list.

LinkFromKeyProperty

Gets or sets the name of the data property that returns the key of the node data that the link data is coming from.

Declaration

public string LinkFromKeyProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the name "From", meaning that it expects the data to have a property named "From" to refer to the link's source node. The name must not be null. If the value is an empty string, GetFromKeyForLinkData(TLinkData) will return the default TNodeKey for all link data objects.

If you want to set this property you must do so before using the model, and especially before you assign Model.

LinkFromPortIdProperty

Gets or sets the name of the data property that returns the optional parameter naming a "port" element on the node that the link data is connected from.

Declaration

public string LinkFromPortIdProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the empty string indicating that one cannot distinguish different logical connection points for any links. The name must not be null nor the value of LinkFromKeyProperty or LinkToKeyProperty. If the value is an empty string, GetFromPortIdForLinkData(TLinkData) will return the default TPort for all link data objects.

If you want to set this property you must do so before using the model, and especially before you assign Model.

LinkKeyProperty

Gets or sets the name of the data property that returns a unique key for each link data object.

Declaration

public string LinkKeyProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is "Key". The name must not be null.

When this property has a value of an empty string, GetKeyForLinkData(TLinkData) will return the default TLinkKey, and FindLinkDataForKey(TLinkKey) will always return null.

If you want to set this property you must do so before using the model, and especially before you assign Model.

LinkLabelKeysProperty

Gets or sets the name of the data property that returns a list of keys of node data that are labels on that link data.

Declaration

public string LinkLabelKeysProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the empty string: "", meaning that the model does not support links owning label nodes.

The name must not be null. If the value is an empty string, GetLabelKeysForLinkData(TLinkData) will return an empty list for all link data objects. You will need to set this property in order to support nodes as link labels.

If you want to set this property you must do so before using the model, and especially before you assign Model.

LinkToKeyProperty

Gets or sets the name of the data property that returns the key of the node data that the link data is going to.

Declaration

public string LinkToKeyProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the name "To", meaning that it expects the data to have a property named "To" to refer to the link's destination node. The name must not be null. If the value is an empty string, GetToKeyForLinkData(TLinkData) will return the default TNodeKey for all link data objects.

If you want to set this property you must do so before using the model, and especially before you assign Model.

LinkToPortIdProperty

Gets or sets the name of the data property that returns the optional parameter naming a "port" element on the node that the link data is connected to.

Declaration

public string LinkToPortIdProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the empty string indicating that one cannot distinguish different logical connection points for any links. The name must not be null nor the value of LinkFromKeyProperty or LinkToKeyProperty. If the value is an empty string, GetToPortIdForLinkData(TLinkData) will return the default TPort for all link data objects.

If you want to set this property you must do so before using the model, and especially before you assign Model.

MakeUniqueLinkKeyFunction

Gets or sets a function that returns a unique key for a link data object.

Declaration

public Func<GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>, TLinkData, TLinkKey> MakeUniqueLinkKeyFunction { get; set; }

Property Value

Type	Description
Func<GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>, TLinkData, TLinkKey>

Remarks

This function is called by MakeLinkDataKeyUnique(TLinkData) when a link data object is added to the model, either as part of a new LinkDataSource or by a call to AddLinkData(TLinkData), to make sure the value of GetKeyForLinkData(TLinkData) is unique within the model. However it will not be called when LinkKeyProperty is the empty string.

The value may be null in order to cause MakeLinkDataKeyUnique(TLinkData) behave in the standard manner. (The default value is null.) You may want to supply a function here in order to make sure all of the automatically generated keys are in a particular format. Setting this property after setting LinkDataSource has no real effect until there is a call to AddLinkData(TLinkData).

If a link data object is already in the model and you want to change its key value, call SetKeyForLinkData(TLinkData, TLinkKey) with a new and unique key.

NodeGroupKeyProperty

Gets or sets the name of the property on node data that specifies the key of the group data that "owns" that node data.

Declaration

public string NodeGroupKeyProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the name "Group", meaning that it expects the data to have a property named "Group" to refer to any containing group.

The value must not be null. If the value is an empty string, GetGroupKeyForNodeData(TNodeData) will return the default TNodeKey for all node data objects.

If you want to set this property you must do so before using the model, and especially before you assign Model.

NodeIsGroupProperty

Gets or sets the name of the boolean property on node data that indicates whether the data should be represented as a group of nodes and links or as a simple node.

Declaration

public string NodeIsGroupProperty { get; set; }

Property Value

Type	Description
string

Remarks

The default value is the name "IsGroup", meaning that it expects the data to have a property named "IsGroup" on those node data objects that should be represented by Groups.

The value must not be null. If the value is an empty string, IsGroupForNodeData(TNodeData) will return false for all node data objects.

If you want to set this property you must do so before using the model, and especially before you assign Model.

Methods

AddLabelKeyForLinkData(TLinkData, TNodeKey)

Adds a node key value that identifies a node data acting as a new label node on the given link data.

Declaration

public void AddLabelKeyForLinkData(TLinkData linkdata, TNodeKey key)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
TNodeKey	key	the key of the new label node.

Remarks

This method only works if LinkLabelKeysProperty has been set to something other than an empty string.

AddLinkData(TLinkData)

When you want to add a link to the diagram, call this method with a new data object.

Declaration

public void AddLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Remarks

This will add that data to the LinkDataSource and notify all listeners that a new link data object has been inserted into the collection.

Presumably the link data object will already have its "from" and "to" node key references set, but it is also possible to set them after the link data is in the model by calling SetFromKeyForLinkData(TLinkData, TNodeKey) and SetToKeyForLinkData(TLinkData, TNodeKey).

This operation does nothing if the link data is already part of this model's LinkDataSource.

AddLinkData(IEnumerable<TLinkData>)

Add to this model all of the link data held in a collection of link data objects.

Declaration

public void AddLinkData(IEnumerable<TLinkData> coll)

Parameters

Type	Name	Description
IEnumerable<TLinkData>	coll	a collection of link data objects to add to the LinkDataSource

ApplyIncrementalJson(string)

Modify this model by applying the changes given in an "incremental" model change in JSON format generated by ToIncrementalJson(ChangedEvent).

Declaration

public override void ApplyIncrementalJson(string s)

Parameters

Type	Name	Description
string	s	a string in JSON format containing modifications to be performed to the model

Overrides

Model<TNodeData, TNodeKey, TSharedData>.ApplyIncrementalJson(string)

Remarks

The expected properties of the argument are described at ToIncrementalJson(ChangedEvent). Incremental changes must be applied in the same order that the changes occurred in the original model.

All of the top-level properties in the JSON, such as NodeKeyProperty, must be the same as for this model. Note that if the model is a GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>, you will have to have set LinkKeyProperty to the name of a property, the same both in the Model as well as in the data that you pass to this method.

This conducts a transaction.

ContainsLinkData(TLinkData)

Decide if a given link data object is in this model.

Declaration

public bool ContainsLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
bool

Remarks

If you do not have a reference to the particular data object that is in the LinkDataSource, you may need to search for it by iterating through that collection, or (more likely), by finding the desired Link in a Diagram and getting that link's Data.

CopyLinkData(TLinkData)

Make a copy of a link data object.

Declaration

public TLinkData CopyLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
TLinkData

Remarks

This uses the value of CopyLinkDataFunction to actually perform the copy, unless it is null, in which case this method just makes a shallow copy of the object.

This does not modify the model -- the returned data object is not added to this model. This assumes that the data's constructor can be called with no arguments. This also makes sure there is no reference to either the "from" or the "to" node of the original data.

CopyNodeData(TNodeData)

This override also makes sure any copied node data does not have a reference to the containing group.

Declaration

public override TNodeData CopyNodeData(TNodeData nodedata)

Parameters

Type	Name	Description
TNodeData	nodedata	an object represented by a node, group, or non-link.

Returns

Type	Description
TNodeData

Overrides

Northwoods.Go.Models.Model<TNodeData, TNodeKey, TSharedData>.CopyNodeData(TNodeData)

FindLinkDataForKey(TLinkKey)

Given a key, find the link data object in this model that uses the given value as its unique key.

Declaration

public TLinkData FindLinkDataForKey(TLinkKey key)

Parameters

Type	Name	Description
TLinkKey	key	a key.

Returns

Type	Description
TLinkData	null if the key is not present in the model.

Remarks

Unless LinkKeyProperty is set to a non-empty string, this model will not automatically assign unique key values for link data objects, and thus this method will always return null.

GetCategoryForLinkData(TLinkData)

Find the category of a given link data, a string naming the link template that the Diagram should use to represent the link data.

Declaration

public string GetCategoryForLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
string

GetFromKeyForLinkData(TLinkData)

From a link data retrieve a value uniquely identifying the node data from which this link is connected.

Declaration

public TNodeKey GetFromKeyForLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
TNodeKey	This may return the default `TNodeKey` if the link is not coming from any node.

GetFromPortIdForLinkData(TLinkData)

From a link data retrieve a value identifying the port object of the node from which this link is connected.

Declaration

public TPort GetFromPortIdForLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
TPort	This may return the default `TPort` if there is no particular port parameter information.

GetGroupKeyForNodeData(TNodeData)

If there is a container group for the given node data, return the group's key.

Declaration

public TNodeKey GetGroupKeyForNodeData(TNodeData nodedata)

Parameters

Type	Name	Description
TNodeData	nodedata	an object represented by a node, group, or non-link.

Returns

Type	Description
TNodeKey	This returns the default `TNodeKey` if there is no containing group data.

GetKeyForLinkData(TLinkData)

Given a link data object return its unique key.

Declaration

public TLinkKey GetKeyForLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link

Returns

Type	Description
TLinkKey

Remarks

This returns the default TLinkKey if there is no key value.

It is possible to change the key for a link data object by calling SetKeyForLinkData(TLinkData, TLinkKey).

GetLabelKeysForLinkData(TLinkData)

Gets a collection of node key values that identify node data acting as labels on the given link data.

Declaration

public ICollection<TNodeKey> GetLabelKeysForLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
ICollection<TNodeKey>	a collection of node keys; an empty list if the property was not present.

Remarks

This method only works if LinkLabelKeysProperty has been set to something other than an empty string.

GetToKeyForLinkData(TLinkData)

From a link data retrieve a value uniquely identifying the node data to which this link is connected.

Declaration

public TNodeKey GetToKeyForLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
TNodeKey	This may return the default `TNodeKey` if the link is not going to any node.

GetToPortIdForLinkData(TLinkData)

From a link data retrieve a value identifying the port object of the node to which this link is connected.

Declaration

public TPort GetToPortIdForLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Returns

Type	Description
TPort	This may return the default `TPort` if there is no particular port parameter information.

IsGroupForNodeData(TNodeData)

See if the given node data should be represented as a group or as a simple node.

Declaration

public bool IsGroupForNodeData(TNodeData nodedata)

Parameters

Type	Name	Description
TNodeData	nodedata	an object represented by a node, group, or non-link.

Returns

Type	Description
bool

Remarks

This value must not change as long as the node data is part of the model. At the current time there is no SetIsGroupForNodeData method.

MakeLinkDataKeyUnique(TLinkData)

This method is called when a link data object is added to the model to make sure that GetKeyForLinkData(TLinkData) returns a unique key value.

Declaration

public void MakeLinkDataKeyUnique(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link

Remarks

The key value should be unique within the set of data managed by this model: LinkDataSource. If the key is already in use, this will assign an unused key to the LinkKeyProperty property on the data when possible.

If you want to customize the way in which link data gets a unique key, you can set the MakeUniqueKeyFunction functional property.

If the link data object is already in the model and you want to change its key value, call SetKeyForLinkData(TLinkData, TLinkKey) and give it a new unique key value.

MergeLinkData(IEnumerable<TLinkData>)

Take a collection of link data objects and update LinkDataSource without replacing the collection and without replacing any existing link data objects that are identified by key.

Declaration

public void MergeLinkData(IEnumerable<TLinkData> coll)

Parameters

Type	Name	Description
IEnumerable<TLinkData>	coll

Remarks

This depends on LinkKeyProperty being a non-empty string.

For link data objects that have the same key value, this makes calls to Set(object, string, object) to update the existing link data object. For new keys, this calls the object's clone method to copy the data and then AddLinkData(TLinkData) to add a new link to the model. For existing links that have keys that are not present in the given collection, this calls RemoveLinkData(TLinkData) to remove the existing link from the model.

This method will error if a new key is added and the TLinkData type is not ICloneable.

This method is typically used when GoDiagram is being used within an application that is maintaining state related to the diagram model. When state is updated, this method can be called to keep the GoDiagram model synchronized. Any updates to the data should use new references since this method will use reference equality to check if a link data object needs to be updated.

This method does not conduct a transaction.

RemoveLabelKeyForLinkData(TLinkData, TNodeKey)

Removes a node key value that identifies a node data acting as a former label node on the given link data.

Declaration

public void RemoveLabelKeyForLinkData(TLinkData linkdata, TNodeKey key)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
TNodeKey	key	key of the label node being removed from the link.

Remarks

Removing a reference to a node data from the collection of link label keys does not automatically remove any node data from the model.

This method only works if LinkLabelKeysProperty has been set to something other than an empty string.

RemoveLinkData(TLinkData)

When you want to remove a link from the diagram, call this method with an existing link data object.

Declaration

public void RemoveLinkData(TLinkData linkdata)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.

Remarks

This will remove that data object from the LinkDataSource and notify all listeners that a link data object has been removed from the collection.

Removing a link data from a model does not automatically remove any associated label node data from the model.

This operation does nothing if the link data is not present in the LinkDataSource.

RemoveLinkData(IEnumerable<TLinkData>)

Remove from this model all of the link data held in a collection of link data objects.

Declaration

public void RemoveLinkData(IEnumerable<TLinkData> coll)

Parameters

Type	Name	Description
IEnumerable<TLinkData>	coll	a collection of link data objects to remove from the LinkDataSource

Set(object, string, object)

This override changes the value of some property of a node data, a link data, or an item data, given a string naming the property and the new value, in a manner that can be undone/redone and that automatically updates any bindings.

Declaration

public override void Set(object data, string propname, object val)

Parameters

Type	Name	Description
object	data	an object typically the value of a Data and represented by a Node, Link, Group, simple Part, or item in a ItemList; or this model's SharedData.
string	propname	a string that is not null or the empty string.
object	val	the new value for the property.

Overrides

Model<TNodeData, TNodeKey, TSharedData>.Set(object, string, object)

Remarks

This override handles link data as well as node data.

This gets the old value of the property; if the value is the same as the new value, no side-effects occur.

SetCategoryForLinkData(TLinkData, string)

Change the category of a given link data, a string naming the link template that the Diagram should use to represent the link data.

Declaration

public void SetCategoryForLinkData(TLinkData linkdata, string cat)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
string	cat	must not be null.

Remarks

Changing the link template for a link data will cause the existing Link to be removed from the Diagram and be replaced with a new Link created by copying the new link template and applying any data-bindings. Note that the new template must be an instance of the same class as the original link. Thus one cannot change the category of a link from an instance of Link to an instance of a subclass of Link, nor vice-versa.

SetFromKeyForLinkData(TLinkData, TNodeKey)

Change the node key that the given link data references as the source of the link.

Declaration

public void SetFromKeyForLinkData(TLinkData linkdata, TNodeKey key)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
TNodeKey	key	This may be the default `TNodeKey` if the link should no longer come from any node.

SetFromPortIdForLinkData(TLinkData, TPort)

Change the information that the given link data uses to identify the particular "port" that the link is coming from.

Declaration

public void SetFromPortIdForLinkData(TLinkData linkdata, TPort portid)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
TPort	portid	This may be the default `TPort` if the link should no longer be associated with any particular "port".

SetGroupKeyForNodeData(TNodeData, TNodeKey)

Change the container group for the given node data, given a key for the new group.

Declaration

public void SetGroupKeyForNodeData(TNodeData nodedata, TNodeKey key)

Parameters

Type	Name	Description
TNodeData	nodedata	an object represented by a node, group, or non-link.
TNodeKey	key	This may be the default `TNodeKey` if there should be no containing group data.

SetKeyForLinkData(TLinkData, TLinkKey)

Change the unique key of a given link data that is already in this model.

Declaration

public void SetKeyForLinkData(TLinkData linkdata, TLinkKey key)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link
TLinkKey	key

Remarks

The new key value must be unique -- i.e. not in use by another link data object. You can call FindLinkDataForKey(TLinkKey) to check if a proposed new key is already in use.

If this is called when LinkKeyProperty is the empty string, this method has no effect. If this is called on a link data object that is not (yet) in this model, this unconditionally modifies the property to the new key value.

SetLabelKeysForLinkData(TLinkData, ICollection<TNodeKey>)

Replaces an Array of node key values that identify node data acting as labels on the given link data.

Declaration

public void SetLabelKeysForLinkData(TLinkData linkdata, ICollection<TNodeKey> arr)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
ICollection<TNodeKey>	arr	a list of node keys

Remarks

This method only works if LinkLabelKeysProperty has been set to something other than an empty string.

SetToKeyForLinkData(TLinkData, TNodeKey)

Change the node key that the given link data references as the destination of the link.

Declaration

public void SetToKeyForLinkData(TLinkData linkdata, TNodeKey key)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
TNodeKey	key	This may be the default `TNodeKey` if the link should no longer go to any node.

SetToPortIdForLinkData(TLinkData, TPort)

Change the information that the given link data uses to identify the particular "port" that the link is going to.

Declaration

public void SetToPortIdForLinkData(TLinkData linkdata, TPort portid)

Parameters

Type	Name	Description
TLinkData	linkdata	an object represented by a link.
TPort	portid	This may be the default `TPort` if the link should no longer be associated with any particular "port".

ToIncrementalData(ChangedEvent)

Produce an object representing the changes in the most recent Transaction.

Declaration

public GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>.IncrementalGLData ToIncrementalData(ChangedEvent e)

Parameters

Type	Name	Description
ChangedEvent	e	a Transaction ChangedEvent for which IsTransactionFinished is true

Returns

Type	Description
GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>.IncrementalGLData	returns either null if no changes occurred, or an object containing incremental model changes for the given Transaction

Remarks

The structure of the object follows the same format as the JSON output from ToIncrementalJson(ChangedEvent).

Note that these incremental changes include the results of undo and redo operations.

For GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>s, this method requires that LinkKeyProperty is not an empty string.

Any node or link data objects contained in the "Modified..." properties will be deep copies of the data in the model. When using this method, we suggest all data classes implement a Clone method such that faithful copies are made in the expected manner.

This method is most commonly used when GoDiagram must communicate with some external data source and maintain integrity between the two while avoiding serialization/deserialization.

myDiagram.ModelChanged += (object sender, ChangedEvent e) => {
  if (e.IsTransactionFinished) {
    var dataChanges = e.Model.ToIncrementalData(e);
    ... update application state/save to database ...
  }
};

Declaration

public string ToIncrementalJson(ChangedEvent e)

Parameters

Type	Name	Description
ChangedEvent	e	a Transaction ChangedEvent for which IsTransactionFinished is true

Returns

Type	Description
string

Remarks

This writes out JSON for a model, but recording only changes in the given Transaction. Instead of the "NodeDataSource" property (and "LinkDataSource" property for GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>s), this will have "Inserted...", "Modified...", and "Removed..." properties.

The "ModifiedNodeData" collection holds node data objects. The "InsertedNodeKeys" and "RemovedNodeKeys" collections hold keys of data, not whole objects, that have been added and/or deleted. The "SharedData" property holds the SharedData object, if it was modified.

Note that it is entirely plausible for the same object be in or referenced by all three collections, because a single Transaction can include adding a node, modifying it, and removing it.

The purpose of this method is to make it easier to send incremental changes to the server/database, instead of sending the whole model. Whereas it has always been easy to perform "batch" updates or "file saves":

myDiagram.ModelChanged += (object sender, ChangedEvent e) => {
  if (e.IsTransactionFinished) {
    var json = e.Model.ToJson();
    // save the whole model upon each transaction completion or undo/redo
    ... send to server/database ...
  }
};

You can now easily send "incremental" updates:

myDiagram.ModelChanged += (object sender, ChangedEvent e) => {
  if (e.IsTransactionFinished) {
    var json = e.Model.ToIncrementalJson(e);
    // record each Transaction as a JSON-format string
    ... send to server/database ...
  }
};

Note that these incremental changes include the results of undo and redo operations. Also, when you might call ApplyIncrementalJson(string), you will need to disable your Changed listener, so that it does not send spurious changes to your database during the process of applying incremental changes from the database.

For GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>s, this method requires that LinkKeyProperty is not an empty string. The incremental JSON for GraphLinksModels will include "ModifiedLinkData", "InsertedLinkKeys", and "RemovedLinkKeys" properties.

The same restrictions on data property names and data property values apply to this method as they do to ToJson().

Implements

IModel

Class GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>

Inheritance

Implements

Namespace: Northwoods.Go.Models

Assembly: Northwoods.GoDiagram.Avalonia.dll

Syntax

Type Parameters

Remarks

Constructors

GraphLinksModel(GraphLinksModel<TNodeData, TNodeKey, TSharedData, TLinkData, TLinkKey, TPort>)

Declaration

Parameters

GraphLinksModel(IEnumerable<TNodeData>, IEnumerable<TLinkData>)

Declaration

Parameters

Properties

ArchetypeNodeData

Declaration

Property Value

Remarks

CopyLinkDataFunction

Declaration

Property Value

Remarks

LinkCategoryProperty

Declaration

Property Value

Remarks

See Also

LinkDataSource

Declaration

Property Value

Remarks

LinkFromKeyProperty

Declaration

Property Value

Remarks

See Also

LinkFromPortIdProperty

Declaration

Property Value

Remarks

See Also

LinkKeyProperty

Declaration

Property Value

Remarks

See Also

LinkLabelKeysProperty

Declaration

Property Value

Remarks

See Also

LinkToKeyProperty

Declaration

Property Value

Remarks

See Also

LinkToPortIdProperty

Declaration

Property Value

Remarks

See Also

MakeUniqueLinkKeyFunction

Declaration

Property Value

Remarks

NodeGroupKeyProperty

Declaration

Property Value

Remarks

See Also

NodeIsGroupProperty

Declaration

Property Value

Remarks

Methods

AddLabelKeyForLinkData(TLinkData, TNodeKey)

Declaration

Parameters