Blocks¶

This section documents the standard available blocks in Lucy.

Binary Output¶

This block is used to make a action sequence return binary data. If no content type is supplied, a default of application/octet-stream is used. When called via a web service call, if a file name is specified, then an additional Content-Disposition header is sent:

Content-Disposition:attachment; filename=<filename>

Inputs¶

Input Name	Description
Data	A binary data object object or text
Content Type	The mime type of the content being returned
File Name	An optional file name to use when the data is downloaded.

JSON Output¶

This block is used to make a action sequence return json data.

Content-Disposition:attachment; filename=<filename>

Inputs¶

Input Name	Description
Data	A JSON object or text

Output¶

Used to return a value from a action sequence. The output is always a JSON structure and the mime type used is application/json. Values are returned as key/value pairs by default. Multiple key/value pairs can be returned by using multiple Output blocks.

If you wish to return a raw structure and not just key/value pairs, then use a single Output block and pass the json structure in text form as the value and leave the Field name empty.

Inputs¶

Fields¶

Field Name	Description
Field	The key name to use

Inputs¶

Input Name	Description
Value	The value to return

Action¶

Used to define a new action in a model. This block represents the action as a whole and properties for the entire action sequence are set from the property panel for this block. You cannot add or delete this block from the block panel as this block is mandatory for an action to exist. When you add a new action, this block gets created automatically. You can add and remove parameters for the action from the property panel. You can also rename the action from the property panel by using the Change Name link. When you delete this block, the entire action sequence will be deleted. You can also delete the entire action sequence by going to the action switcher and using the icon for the corresponding action sequence.

See also

Actions are covered in depth in Actions

Activate¶

Marks the current model instance as active.

Outputs¶

Output Name	Description
Output	The key of the model instance

AddDays¶

Adds the given number of days to a timestamp and outputs a new timestamp. The first input specifies a valid timestamp. It can also be a textual representation of a timestamp The days to add can be negative, allowing you to calculate a timestamp in the past.

Since timestamp values are in UTC, no day-light savings are observed.

See also

Supported date and time formats

Inputs¶

Input Name	Description
Input 1	A valid timestamp
Input 2	The number of days to add

Outputs¶

Output Name	Description
Output	A new timestamp

Add¶

Adds two floating point numbers together. If any non-numeric values are passed (like text), then zero is is used in place of that input.

Inputs¶

Input Name	Description
Input 1	The first value to operate on
Input 2	The second value to operate on

Outputs¶

Output Name	Description
Output	The result of both numbers added together.

AddMinutes¶

Adds the given number of minutes to a timestamp and outputs a new timestamp. The first input specifies a valid timestamp. It can also be a textual representation of a timestamp The minutes to add can be negative, allowing you to calculate a timestamp in the past.

Since timestamp values are in UTC, no day-light savings are observed.

See also

Supported date and time formats

Inputs¶

Input Name	Description
Input 1	A valid timestamp
Input 2	The number of minutes to add

Outputs¶

Output Name	Description
Output	A new timestamp

AddMonths¶

Adds the given number of months to a timestamp and outputs a new timestamp. The first input specifies a valid timestamp. It can also be a textual representation of a timestamp The months to add can be negative, allowing you to calculate a timestamp in the past.

Since timestamp values are in UTC, no day-light savings are observed.

See also

Supported date and time formats

Inputs¶

Input Name	Description
Input 1	A valid timestamp
Input 2	The number of months to add

Outputs¶

Output Name	Description
Output	A new timestamp

AddWeblet¶

Add a weblet to the dynamic dashboard of a model. Select any weblet from the system to be shown. When you choose a weblet, the input pins of the block will change to reflect the inputs that are required from the weblet.

Note

The colors and placement of the weblet are chosen dynamically by Lucy based on the current dashboard configuration.

Inputs¶

ColorScheme:Number:The color scheme to use for the weblet. Leave this empty to let Lucy dynamically choose the best color scheme based on the current dashboard configuration. This should be a number from 1-12.

Inputs¶

Input Name	Description
Params	The parameters to pass to the weblet. This can either be a json object as text or a dictionary.

AddYears¶

Adds the given number of years to a timestamp and outputs a new timestamp. The first input specifies a valid timestamp. It can also be a textual representation of a timestamp The years to add can be negative, allowing you to calculate a timestamp in the past.

Since timestamp values are in UTC, no day-light savings are observed.

See also

Supported date and time formats

Inputs¶

Input Name	Description
Input 1	A valid timestamp
Input 2	The number of years to add

Outputs¶

Output Name	Description
Output	A new timestamp

Get Attribute¶

Gets the value of an attribute in an model instance. You can create this block from the Attribute Editor by going to an attribute and dragging the getter icon into the design area.

This block returns the value of the attribute when the block is first called. If the block’s value is read multiple times (ie, there are multiple connections from the output pin), then the same value is returned each time it is called.

Note

If you expect the value of an attribute to change after it is first read, drag in a second block to read it again later.

Outputs¶

Output Name	Description
Output	The value of the attribute when the block is executed.

Set Attribute¶

Sets the value of an attribute in an model instance. You can create this block from the Attribute Editor by going to an attribute and dragging the getter icon into the design area.

This block returns the value of the attribute when the block is first called. If the block’s value is read multiple times (ie, there are multiple connections from the output pin), then the same value is returned each time it is called.

Note

If you expect the value of an attribute to change after it is first read, drag in a second block to read it again later.

Outputs¶

Output Name	Description
Output	The value of the attribute when the block is executed.

CallAction¶

Call an action in a model. Use this to run a action sequence from within the current action sequence. Execution is halted until execution finishes and the result is then made available. If an error ocurred during execution of the action, then the current action sequence is aborted with an error.

Any parameters to be passed to the action can also be passed as inputs. Click the Add Input Parameter link in the Properties Panel to add additional inputs. You can quickly add multiple inputs at once by specifying them as a comma separated list.

Note

When calling an action in this way, you can only specify parameters to the action in key/value format. Unstructured JSON cannot be used.

If the action returns a Dictionary then you can auto-extract values by adding new output pins. Click the ‘Add Output Parameter’ link in the Properties Panel to add outputs.

Fields¶

Field Name	Description
Model	The name of the model in which the action to be called is defined in
Action	The name of the action to call

Inputs¶

Input Name	Description
Instance	the key for the model instance to call the action in. If left off, the action will be called on the model.

Outputs¶

Output Name	Description
All Output	Contains the output from calling the action

Call Data Source¶

Query a data source in a linked UI Bundle and return the result of it. The data source must be defined in a UI bundle that is linked to the specified model.

If an error ocurred during execution of the action, then the current action sequence is aborted with an error.

All data sources return a result set.

Inputs¶

See also

Working with Data Sources

Fields¶

Field Name	Description
Model	The name of the model in which the action to be called is defined in
Data Source	The name of the data source to query. The data source is defined in the UI Bundle linked to the specified model.

Inputs¶

Input Name	Description
Multiple	Any parameters to be passed to the action can also be passed as inputs. Click the Add Input Parameter link in the Properties Panel to add additional inputs. You can quickly add multiple inputs at once by specifying them as a comma separated list.

Outputs¶

Output Name	Description
All Output	Contains the output from calling the action. This will be a result set. This will often contain multiple ditionaries. You can treat it as a single dictionary in which case, retrieving values will return from the first item. You can also feed the output to any list processing block like a Repeat Action block.
Multiple	You can can auto-extract values from the first result by adding new output pins. Click the ‘Add Output Parameter’ link in the Properties Panel to add outputs.

Call Service¶

Call a service in an iviva app.

All service return a result set. You can auto-extract values by adding new output pins. Services are of two forms:

<app>.<model>:<service>

or

<app>.<service>

Warning

Make sure the service you are calling is supported. Many services may be internal and subject to change.

Click the ‘Add Output Parameter’ link in the Properties Panel to add outputs.

Fields¶

Field Name	Description
Service	The service to be called

Outputs¶

Output Name	Description
All Output	Contains the result set from calling the service

Call Web Service¶

Use this block to call any third party webservice

Combine¶

Combines two pieces of text together. Any inputs which are not textual are converted to a textual representation before combining them.

Note

If you need to combine multiple pieces of text together, avoid chaining Combine blocks. Instead, use a Template block.

Inputs¶

Input Name	Description
Input 1	First piece of text
Input 2	First piece of text

Outputs¶

Output Name	Description
Output	The combined text

CurrentItem¶

Returns the key of the current model instance the action sequence is running. If the action sequence is running on a model then 0 is returned.

Outputs¶

Output Name	Description
Output	The key of the current model instance. 0 if the current action sequence is running in a model.

CurrentUser¶

Returns information about the user the current action sequence is being executed by.

If the action sequence is executed through an API call, then the user associated with the API Key is used. If the action sequence is run by some automated job in the backend, then no user is present and all outputs will be empty.

Outputs¶

UserKey: The key of the logged-in user
FullName: The full name of the user
Phone: The user’s phone number
Email: The user’s email address
LoginID: The iviva login id for the user
UserType: The user type that the user is tagged with in iviva
SiteKey: The key of the site that the user belongs to

DateTime¶

Construct a new timestamp from an year/month/day/hour/minute/second

Inputs¶

Input Name	Description
Year
Month
Day
Hour
Minute
Second

Outputs¶

Output Name	Description
Output	A timestamp constructed from the given inputs

Day Of Month¶

Extracts the day component of a date/time field.

Inputs¶

Input Name	Description
Input	A valid datetime object or the datetime as text specified in a valid format

Outputs¶

Output Name	Description
Output	The day of the month (0-28/30/31)

Day Of Week¶

Extracts the day of week for the date/time field.

Inputs¶

Input Name	Description
Input	A valid datetime object or the datetime as text specified in a valid format

Outputs¶

Output Name	Description
Output	Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday

Deactivate¶

Deactivae the current model instance. This block has no effect when being called from a model.

Deadband¶

Emits an output only if the input has changed by the given range or if the holding time has expired. Useful if you want to only take action if a value changes by a large amount.

Fields¶

Field Name	Description
Range	The range within which, the value will be held. This can be a percentage like ‘5%’ meaning, deviations beyond 5% of the current value will cause the output to be set. It can also be a value like ‘0.01’ meaning if the value changes by more than 0.01 the output will be set.

Inputs¶

Input Name	Description
Input	The value to check

Outputs¶

Output Name	Description
Output	The input value gets emmitted if it passes the deadband criteria

Debug¶

Use the Debug block to log data to the debug console.

See also

debugging

Inputs¶

Input Name	Description
Input	The object to be dumped to the debug log. This is serialized to JSON when logged.
Message	Any additional message to be recorded along with the object

Outputs¶

Output Name	Description
Output	The objectt that was sent as input is passed through as output

Delay¶

Pauses execution for the specified time. The next connected block is executed only once the delay ends. Note that any other branches in your action sequence will continue to execute while this block is on hold.

Inputs¶

Input Name	Description
Time	The number of milliseconds to pause

Divider¶

Inputs¶

Input Name	Description
Input 1	The first value to operate on
Input 2	The second value to operate on

Equals¶

Compares if two inputs are equal. When matching, both inputs are converted to text and matched. Comparisons are case-insensitive.

Inputs¶

Input Name	Description
Input 1	The first value to compare
Input 2	The value to compare against

Outputs¶

Output Name	Description
True	Writes the first input to this port if the condition is met. Else, doesn’t write anything
False	Writes the first input to this port if the condition is not met. Else, doesn’t write anything.

ES6Javascript¶

Executes custom javascript code.

You have access to ES6 Javascript, including the use of async/await and Promises. If you have code that is running asynchronously, the block will finish only after your async code is done.

You should make this explicit by explicitly calling runtime.done() when you are finished with execution.

This block has access to its inputs by using the runtime.inputs() function. This will return a Javascript object containing all inputs. You can terminate the script and write data to the output ports by calling runtime.done(outputs)

Where outputs is a dictionary of values to write to the output pins. When runtime.done() is called, the script terminates.

If no data is written to an output port, that port’s connections are not followed. So you can use a javascript block to handle control-flow by choosing which outputs to write to, based on the inputs. For reference on what functions are available in javascript, see the Javascript Library section.

See also

Javascript Library

See also

For more information on how data type conversions work with Javascript code, see Datatypes in Lucy

Fields¶

Field Name	Description
Name	A label for the javascript block to show in the designer
Code	The actual javascript code

Inputs¶

Input Name	Description
Multiple	Any inputs you add can be accessed via `runtime.inputs()`

Outputs¶

Output Name	Description
Multiple	Any outputs you add can be written to via `runtime.done({..})`

Event Trigger¶

Used to listen for and react to events that are sent into the system.

See also

Events are covered in depth in Event Stream and Event Handling

Exception¶

Generate an error and halt execution of the action sequence. An error will be thrown with the specified error message and no further execution of that action sequence will occur. This is useful to signal error conditions in the action sequence as well as for input validation for action sequences that are meant to be called from a UI.

Inputs¶

Input Name	Description
Message	The error message to be used when the error is generated

Exists¶

Checks if the input value is valid. Writes to the True output if the value is valid. If the value is invalid, the False output is written to. Only one of them will be executed.

The following values are deemed invalid:

empty

0

false

All other values are deemed to be valid

Inputs¶

Input Name	Description
Input 1	The value to check for existence

Outputs¶

Output Name	Description
True	The input value is written to this output if the input is valid
False	The input value is written to this output if the input is invalid

ExtractValue¶

Extracts a value from a dictionary. Specify an input dictionary and a field, and the value for that field from the dictionary will be written to the output. If the dictionary does not contain the given field, empty text will be written to the output.

Fields¶

Field Name	Description
Field	The name of the field, for which a value should be extracted.

Inputs¶

Input Name	Description
Input	The input dictionary

Outputs¶

Output Name	Description
Output	The value of the specified key in the dictionary

Fire Event¶

Use this block to trigger a new event. The event being triggered does not have to be registered in the system. Any ad-hoc event id can be used. Any input parameters you specify get sent as part of the event payload.

Fields¶

Field Name	Description
EventID	The id of the event to trigger

Inputs¶

Input Name	Description
Multiple	Add new inputs by clicking the ‘Add Input Parameter’ link in the properties panel.

Convert JSON¶

Parses a json block into a dictionary or a result set The input json structure must either be an object or an array of homogenous objects.

Inputs¶

Input Name	Description
Input	The json text to be parsed

Outputs¶

Output Name	Description
Output	The resulting dictionary or result set

Get Value¶

Gets an arbitrary value that was written using Set Value.

Inputs¶

Input Name	Description
Key	The key from which the value should be read

Outputs¶

Output Name	Description
Value	The value to be read. Empty if the key doesn’t exist or has expired.

Greater¶

Checks if the first value is greater than the second value. (Inputs are converted to floating point when compared)

Inputs¶

Input Name	Description
Input 1	The first value to compare
Input 2	The value to compare against

Outputs¶

Output Name	Description
True	Writes the first input to this port if the condition is met. Else, doesn’t write anything
False	Writes the first input to this port if the condition is not met. Else, doesn’t write anything.

After¶

Checks if the first datetime occurs after the second date time.

Inputs¶

Input Name	Description
Input 1	The first value to compare
Input 2	The value to compare against

Outputs¶

Output Name	Description
True	Writes the first input to this port if the condition is met. Else, doesn’t write anything
False	Writes the first input to this port if the condition is not met. Else, doesn’t write anything.

Hour¶

Extracts the hours component of a date/time field.

Inputs¶

Input Name	Description
Input	A valid datetime object or the datetime as text specified in a valid format

Outputs¶

Output Name	Description
Output	The hours component of the date/time (0-23)

Increment By Value¶

Increments a counter by the specified value. The counter can have an optional expiry which will clear it if its updated within the given time. Using an expiry is useful to track how many times an event occurs within a given time period.

Fields¶

Field Name	Description
Expiry	The expiry time in seconds for the counter. If the counter is not updated within the given time, it will be deleted. This is optional. If no expiry is given, the counter lives forever

Inputs¶

Input Name	Description
Key	The name of the counter. You can give any name. Counters are shared across all models. If a counter with this name doesn’t exist, it will be created and the value set to 0.
Value	The numeric value to increment the counter by.

Outputs¶

Output Name	Description
Output	The new value of the counter after incrementing.

Add Headers¶

Add additional headers to be included in the api response

Javascript¶

Executes custom javascript you write. This block has access to its inputs by reading data from inputs.inputName; You can write outputs by writing data to output.OutputName. If no data is written to an output port, that port’s connections are not followed. So you can use a javascript block to handle control-flow by choosing which outputs to write to, based on the inputs. For reference on what functions are available in javascript, see the Javascript Library section.

See also

Javascript Library

Fields¶

Field Name	Description
Name	A label for the javascript block to show in the designer
Code	The actual javascript code

Inputs¶

Input Name	Description
Multiple	Any inputs you add can be accessed via `inputs.inputName`

Outputs¶

Output Name	Description
Multiple	Any outputs you add can be written to via :code:’outputs.outputName’

Make JSON Array¶

Makes a JSON array from multiple inputs. Optionally provide an existing JSON array and appends the new items to that.

You can add multiple input pins and the value from each pin is taken and combined together to make an array.

The first input pin - JSON List is fixed. You can optionally pass an existing JSON array to it and it will combine the items from that array with the other iput pins and output a new JSON Array.

Exception with JSON¶

Generates an errorr and halts execution.

The error message will be formatted as a JSON dictionary. You can add multiple pins to represent keys in the JSON dictionary. Pin names will be the key names and the values fed to the pin will be the value of that item in the dictionary.

The values fed to the pins can be:

text

a dictionary

a JSON value

an Array

This block is useful for building an API action sequence that will return an error in JSON format. You can use the Code pin to specify an HTTP Status Code for the response. This block will also add a Content-Type header to the response with the value set to application/json.

Make JSON Object¶

Use this block to create a new JSON object. You can add multiple input pins. The names of the pins are keys. The values will be the value of the corresponding item in the object..

For example, if you add 2 input pins - ‘A’, ‘B’ and ‘C’ and give the corresponding values as ‘1’ , ‘2’ and {"D":3}, then the output JSON object will be {"A":"1","B":"2","C":{"D":3}}

The input can be

text

a dictionary

a JSON value

an Array

Outputs¶

Output Name	Description
Output	JSON Object

Extract JSON Path¶

Takes the input JSON value and extracts a sub-component of it using the path expression given.

See also

http://jsonpath.com for more information

Inputs¶

Input Name	Description
JSON Object	The JSON to extract a sub-component from. This can be a text representation of JSON or a JSON value.
Path	The JSON Path expression to use to find the component to extract from it.

Outputs¶

Output Name	Description
All	Returns all matches as an array
First	Returns the first match. Since its common to only have one match or to only want to process one, this is provideed as a convenience so you don’t have to extract the first one out of the array

Lookup¶

Use this block to find a value corresponding for the input given.

You can populate a table of key/value pairs. And then, the input is matched against the table and if it matches any keys, the corresponding value is sent to the output.

This is useful to take, say, a department as input and return the email address of the department’s supervisor. Use the Edit Data link in the property panel to bring up the editor where you can edit the key/value pairs.

Inputs¶

Input Name	Description
Input	The key to look up

Outputs¶

Output Name	Description
Output	The corresponding value to obtain

Less¶

Checks if the first value is less than the second value. (Inputs are converted to floating point when compared)

Inputs¶

Input Name	Description
Input 1	The first value to compare
Input 2	The value to compare against

Outputs¶

Output Name	Description
True	Writes the first input to this port if the condition is met. Else, doesn’t write anything
False	Writes the first input to this port if the condition is not met. Else, doesn’t write anything.

Before¶

Checks if the first datetime occurs prior to the second date time.

Inputs¶

Input Name	Description
Input 1	The first value to compare
Input 2	The value to compare against

Outputs¶

Output Name	Description
True	Writes the first input to this port if the condition is met. Else, doesn’t write anything
False	Writes the first input to this port if the condition is not met. Else, doesn’t write anything.

Merge Data¶

Merge a name/value pair into a dictionary. Use this to add a name/value pair to an existing dictionary. Or, to create a new dictionary with a given name/value pair. If the Input dictionary is empty, then a new dictionary is created and the name/value pair are added to it. If the Input dictionary exists, then, it is merged with the new name/value pair and the new dictionary is returned in the output. If the Input contains a value but is not a dictionary, a default new dictionary is created with one name/value pair with a name value and the value being the input value.

Note

If the name being merged already exists in the dictionary, then it will be overwritten with the new value

Inputs¶

Input Name	Description
Input	The dictionary to add the new name/value pair into
Name	The name of the field to be added to the dictionary
Value	The value to be added to the dictionary

Outputs¶

Output Name	Description
Output	The new dictionary containing the newly added name and value

Minute¶

Extracts the minutes component of a date/time field.

Inputs¶

Input Name	Description
Input	A valid datetime object or the datetime as text specified in a valid format

Outputs¶

Output Name	Description
Output	The minutes component of the date/time (0-59)

MqttPublish¶

Publish a message on an Mqtt topic. This will be sent to the mqtt broker which is configured in your Lucy dashboard.

Inputs¶

Input Name	Description
Topic	The topic to send the message to
Message	The message to send. This should be text

Multiply¶

Inputs¶

Input Name	Description
Input 1	The first value to operate on
Input 2	The second value to operate on

Not Equal¶

Compares if two inputs are not equal. When matching, both inputs are converted to text and matched. Comparisons are case-insensitive.

Inputs¶

Input Name	Description
Input 1	The first value to compare
Input 2	The value to compare against

Outputs¶

Output Name	Description
True	Writes the first input to this port if the condition is met. Else, doesn’t write anything
False	Writes the first input to this port if the condition is not met. Else, doesn’t write anything.

Not Installed¶

This block represents a block that has not been installed

GenerateID¶

Generate a unique id for an object by using the default ID format settings in iviva.

The ID format settings are available in iviva under /Apps/System/accountsettings Different prefixes may have different ID formats, depending on the application that uses the prefix. If you use a custom prefix, the default settings are used. You can also choose to pick up the settings for a given ID prefix but override the actual prefix in the ID with one of your own. This is useful, for example, if you want to generate IDs for devices using the format:

DVC/<devicetype>/<running number>
Ex: DVC/AHU/01
    DVC/FCU/02
    DVC/PUMP/03

If want the running number to remain the same for all devices regardless of the device type, then use ‘DVC’ as the prefix, but override the actual generated prefix with ‘DVC/<deivcetype>’

Inputs¶

Input Name	Description
Prefix	The prefix to give for the generated id.
Override	Use the prefix to derive the running number and date format, but override the actual prefix in the id with the one specified. You can leave this empty usually.

Outputs¶

Output Name	Description
Output	The generated id.

GetAccountSetting¶

Reads a global setting in the current iviva account.: Account settings are stored as key/value pairs, with values being text-based.

Inputs¶

Input Name	Description
Key	The setting to read

Outputs¶

Output Name	Description
Output	The setting value. An empty string is returned if the setting is not present.

GetUserByID¶

Retrieve the iviva user key for the user having the specified login id.: Returns nothing if a user with the specified login id does not exist.

Inputs¶

Input Name	Description
LoginID	The login id of the `iviva` user

Outputs¶

Output Name	Description
Output	The user key of the user having the specified login id

Now¶

Returns the current timestamp in UTC format.

Outputs¶

Output Name	Description
Output	The current timestamp

PublishMessage¶

Publish a message to the message bus.

See also

Publishing Messages

Inputs¶

Input Name	Description
Channel	The channel to publish the message on
Message	The message to publish. This should be text.

PublishMessageToQueue¶

Publish a message to the message queue.

This block returns an integer error code depending on if the message was successfully published or not.

0 - The message was successfully published on the queue and sent over the message bus
2 - The message was not published on the queue successfully
3 - The message was published on the queue but was not sent over the message bus.

See also

Publishing Messages

Inputs¶

Input Name	Description
Channel	The channel to publish the message on
Message	The message to publish. This should be text.
Lifetime	The lifetime of the message, in seconds. If not set, the message will never expire.

Outputs¶

Output Name	Description
Output	Error code describing if the message got published or not.

SetAccountSetting¶

Writes a global setting in the current iviva account.: Account settings are stored as key/value pairs, with values being text-based.

Inputs¶

Input Name	Description
Key	The name to write
Value	The value to write

Outputs¶

Output Name	Description
Output	The value that was written

Parse Date¶

This block converts a textual representation of a timestamp into an actual timestamp. See Supported date and time formats for more information on the formats in which the input can be specified. If the input is not in any of those formats, Lucy tries to make a guess as to how it should be intrepreted. Don’t like the sound of that? Then specify the date in a valid format :)

Inputs¶

Input Name	Description
Input String	The string to convert into a timestamp

Outputs¶

Output Name	Description
Output Date	The timestamp

Parse JSON¶

This block parses json text into a JSON object.

If the input does not contain valid json, this block will raise an error.

Inputs¶

Input Name	Description
Input	The textual representation of JSON

Outputs¶

Output Name	Description
Output	The corresponding JSON value.

InjectValue¶

Used to inject a value into a block. This is primarily used for flow-control in blocks that don’t support a trigger pin. The value written to the input pin is written to the output only when the trigger port has a value written to it. This is useful to ensure that certain parts of a sequene are executed before another.

See also

See Flow of Data and Execution for more information on controlling data flow through a action sequence

Inputs¶

Input Name	Description
Value	The value to inject when something is written to the trigger port

Outputs¶

Output Name	Description
Output	The value specified in the input. This is written only once the trigger port has a value written to it.

PublishMessage¶

Publish a message to the message bus.

See also

Publishing Messages

Inputs¶

Input Name	Description
Channel	The channel to publish the message on
Message	The message to publish. This should be text.

RegexCapture¶

Specify a regular expression with capture groups and extract all matches from a given input text. For each capture group you specify, add an output pin with a name matching the name of the capture group. All input text that matches each capture group will be written to the corresponding output pin.

Inputs¶

Input Name	Description
String	The string to match against
Pattern	The regular expression pattern to use

Outputs¶

Output Name	Description
Multiple	Add an output for each capture group in your regular expression. A list of matched strings for that capture group will be written to the output.

Repeat Action¶

The Repeat Action block is used to loop through a list of data and execute an action for each item in the list.

Specifying Inputs¶

The input list can be a result set, a list of strings (ex, output of a Split Text block) or any javascript array (the output from a Javascript block).

Specifying the looping logic¶

The way a repeat block works, is that it executes an Action Start block for each item in the input list. To specify what action should execute, drop in an Action Start block and then link the Action output pin of the Repeat block to the blue pin on the Action Start block. This action will be executed for each item in the loop. Since the logic is executed in a different action, you cannot link blocks from your current sequence (where your repeat block is) to items in the loop action.

Passing items to the action¶

Each time the action block is called, a single item from the list is passed as input to the action, along with any data specified in the Extra input. If the item being passed to the action block is a dictionary or result set, then it will be split into key/value pairs and sent to the action. This means, you can add output pins in the Action Start block to auto extract the fields of the dictionary. The Extra parameter is passed as an extra key/value pair with the key name being Extra.

Note

If your dictionary happens to have a key called Extra it will get overwritten by the Extra parameter passed into the repeat block.

If the item being passed into the action block is not a dictionary or result set then the item is passed as a single key/value pair with a key Item. The Extra parameter is passed as a second key/value pair with the key name being Extra. In this case, you can add two output pins to the action block to extract the values:

Item

Extra

Order of execution¶

Lucy makes no guarantees about the order of execution of items in the list. They are sent to the actions in order, but Lucy may choose to optimize the sequence by running multiple items in parallel.

Error Handling¶

Any error that occurs during the execution of the loop action does not affect subsequent items in the list. Each will get executed independent of errors to any previous executions.

Inputs¶

Input Name	Description
Action	The action block to execute for each item in the list
Items	The list of items to execute. This can be a result set or a list or array
Extra	Any extra data to be passed along to the action that is called for each item in the list. Use this to send some extra fixed set of information to each item.

Outputs¶

Output Name	Description
Done	The number of items processed is written to this output once all inputs have been processed. Anthing attached to this pin will execute after the full loop is done.

Schedule Action¶

Schedule an action to be executed later. To schedule an action, drag in an Action Start block and build your flow in that block. Then link the Action pin from the schedule block to the blue pin of the Action Start block. Then, when the schedule block fires, it will setup a scheduler to execute that action at some later point.

The action is executed exactly once and the schedule is removed once the action is executed.

Inputs¶

Input Name	Description
Time	The timestamp at which the action should be executed
Action	The action to execute.

Set Value¶

Associate a value with a key. You can specify an optional expiry time in seconds to make the value get deleted if it’s not updated within the given time. This block is useful for storing arbitrary values. Using the expiry is useful for storing real-time values that need to get deleted if they are stale. If the value doesn’t get updated in the prescribed time, it will be deleted.

Fields¶

Field Name	Description
Expiry	The expiry time in seconds for the value. This can be empty to indicate no expiry.

Inputs¶

Input Name	Description
Key	The key to write the value to
Value	The value to write

SetName¶

Sets the name associated with the current model instance.

See also

Attributes of Model Instances

Inputs¶

Input Name	Description
Name	The name to set for the current model instance.

Outputs¶

Output Name	Description
Output	The name is passed through to the output.

Split Text¶

Create a list from a comma separated list of items.

Actually, create a list by splitting text by any delimiter.

Inputs¶

Input Name	Description
Text	The text to split
Delimiter	The delimiter to use. Can be a character or some text. Typically, `,` is used

Outputs¶

Output Name	Description
Items	A list of split items.

String Interpolation¶

Warning

This block has been deprecated. Use a Template block instead.

Subtract¶

Subtract the second floating point number from the first one. Both inputs are converted into floating point - if any non-numeric inputs are passed, they are treated as 0.

Inputs¶

Input Name	Description
Input 1	The value to subtract from
Input 2	The value to subtract

Outputs¶

Output Name	Description
Output	The result of the subtraction

Template¶

Use a template to generate textual output.

This block lets you define a template and specify variables to it to generate a final textual output.

Use it to compose a long messages suitable for email or sms or other types of notification. It can also be used easily generate xml blocks with placeholders replaced by input values.

The templating system lets you do simple variable substitution, as well as looping through result sets and transformting values.

Any text you enter will get directly passed to the output, unless it is enclosed in either ${...} or #{...} blocks.

Variables can be specified using #{varname} syntax. All inputs to the block are available as variables. The names of the variables will be the names of the input pins.

Example (assume two input pins have been added - name and ticketid): .. code:
Dear #{name}

Your ticket has been filed in our system.

Your ticket id is: #{ticketid}

thanks

Support Team
If the input contains a dictionary or result set then you can access fields of the object using . syntax.

Example (assuming the block has an input called input1 which contains a dictionary of user details):
Dear #{input1.FirstName},
Your blah blah blah will be available shortly

thanks
In the case of a result set, the first field from the first record in the result set is used.

If the inputs to the block contain a list of items (a list of strings, or a result set for example), you can loop through the list using a ${for }...${end} block. Any thing within that block will get repeated for each item in the list. The ${for} blocks can also be nested for using loops within loops.

The syntax for the loop is:
${for loop-variable in list}
    ....
${end}
Within the for block, you can use #{loop-variable} to access each item. You can also use #{index} to access the iteration count (starts with zero)

Example (given a list of strings, say by using the Split Text block):
Here are your tasks:
${for x in items}
    * #{x}
${end}
If the list is a result set then individual fields of the result could be accessed using the . operator.

Example (given an input coming from a datasource)
Here are your tasks:
${for row in tasks}
    #${row.TaskName} - Due on: #{row.Deadline}
${end}
The templating system has many functions that can be used to transform variables or generate values. Functions use the following syntax:
functionname()
functionname(arg1,arg2,arg3,...)
Each argument could be a variable, a string literal, a number or the result of another function call.

String literals are enclosed in square brackets: [this is a string literal]

Example:
functionname(arg1func(),12,[third argument])

Available Functions:

Function Name Description

html(content) Escape the html inside content. This converts ‘<’ into & and so on

date(text) Parses a textual representation of a date/time into a timestamp

dateonly(date) Removes the time component of a timestamp - ie, sets the time to 12:00AM

addmonths(date,months) Add months to the timestamp date and return the new timestamp

adddays(date,months) Add days to the timestamp date and return the new timestamp

addyears(date,months) Add years to the timestamp date and return the new timestamp

addminutes(date,months) Add minutes to the timestamp date and return the new timestamp

addhours(date,months) Add hours to the timestamp date and return the new timestamp

select(list,field-to-select,field-to-filter,value-to-filter) Given a list of items list, return the field field-to-select of the first result where the value of the field field-to-filter matches value-to-filter. Example: select(items,[Name],[UserKey],12) - selects the FirstName field of the user having UserKey=12

selectfromindex(list,index,field) Given a list of items list, return the field field from the item in the list with zero-based index index. Example: selectfromidnex(items,3,[Name]) - Selects the name field from the 4th item in the list

concat(item1,item2,item3,...) Performs string concatenation on a list of items

sum(item1,item2...) Adds all the items together. Items are converted to integers before being added together.

mod(item1,item2) Performs a modulus operation: item1 % item2. Both items are converted to integers first.

div(item1,item2) Divides item1 by item2. Both items are converted to integers first.

mul(item1,item2,....) Performs integer multiplication on all items.

fmul(item1,item2,...) Performs floating point multiplication on all items

random(start,end) Returns a random integer between start and end

randomchoice(item1,item2...) Picks one of the specified items at random

startswith(haystack,needle) Returns true if the text haystack begins with the text needle. This is case-insensitive.

substring(text,index,[length]) Returns a substring of text starting at index. If length is specified, then a maximum of that many characters is returned. Otherwise, the full text from the index up to the end of the text is returned.

escapexml(text) Escapes the text so that its suitable for including within an xml block. Example: escapexml([Ben & Jerrys]) translates to Bend & Jerrys

datetimeformat(timestamp ,[timezone]) Given a timestamp, converts it into a nicely formatted string according to the date and time formats given in iviva account settings. Optionally specify a Time Zone Codes to convert the timestamp into before formatting

dateformat(timestamp) Given a timestamp, converts it into a nicely formatted date string according to the date format given in iviva account settings.

Fields¶

Field Name	Description
Template	The actual template to use.

Inputs¶

Input Name	Description
Multiple	The inputs to be accessed as variables. You can define as many as you need.

Outputs¶

Output Name	Description
Output	The final text output after rendering the template using the inputs

Serialize JSON¶

Serialize the input object into JSON text. If the input is a dictionary, it will get serialized as a JSON object:

{"key1":"value1","key2":"value2"}

If the input is a result set, it will get serialzed as an array of objects:

Any other type of input gets converted to text and stored in a JSON object with a key called ‘value’

{"value":"2015-01-01 12:240"}

Inputs¶

Input Name	Description
Input	The object to be serialized as JSON.

Outputs¶

Output Name	Description
Output	The serialized JSON.

Unknown Action¶

This block represents all blocks that could not be loaded. This likely means you imported a model without having all the connectors in place

Wait on Channel¶

Waits on a channel for message.

Inputs¶

Input Name	Description
Channel	Channel to listen for a message
Timeout	Time to wait for a message in millisecond

Outputs¶

Output Name	Description
Error	Error that occurred during processing
Message	Message received on the channel

Year¶

Extracts the year component of a date/time field.

Inputs¶

Input Name	Description
Input	A valid datetime object or the datetime as text specified in a valid format

Outputs¶

Output Name	Description
Output	The year, as a number