--- title: Helper Functions --- Some common functions are provided for use in custom report and label templates. To include these, load the `report` functions at the start of the template: ```html {% raw %} {% load report %} {% endraw %} ``` !!! tip "Use the Source, Luke" To see the full range of available helper functions, refer to the source file [report.py]({{ sourcefile("src/backend/InvenTree/report/templatetags/report.py") }}) where these functions are defined! ## Assigning Variables When making use of helper functions within a template, it can be useful to store the result of the function to a variable, rather than immediately rendering the output. For example, using the [render_currency](#currency-formatting) helper function, we can store the output to a variable which can be used at a later point in the template: ```html {% raw %} {% load report %} {% render_currency 12.3 currency='USD' as myvar %} ... ... Result: {{ myvar }} {% endraw %} ``` Note the use of the `as` keyword to assign the output of the function to a variable. This can be used to assign the result of a function to a named variable, which can then be used later in the template. ## Data Structure Access A number of helper functions are available for accessing data contained in a particular structure format: ### Index Access To return the element at a given index in a container which supports indexed access (such as a [list](https://www.w3schools.com/python/python_lists.asp)), use the `getindex` function: ::: report.templatetags.report.getindex options: show_docstring_description: false show_source: False #### Example ```html {% raw %} {% getindex my_list 1 as value %} Item: {{ value }} {% endraw %} ``` ### Key Access To return an element corresponding to a certain key in a container which supports key access (such as a [dictionary](https://www.w3schools.com/python/python_dictionaries.asp)), use the `getkey` function: ::: report.templatetags.report.getkey options: show_docstring_description: false show_source: False #### Example ```html {% raw %} {% endraw %} ``` ## Database Helpers A number of helper functions are available for accessing database objects: ### order_queryset The `order_queryset` function allows for ordering of a provided queryset. It takes a queryset and a list of ordering arguments, and returns an ordered queryset. ::: report.templatetags.report.order_queryset options: show_docstring_description: false show_source: False !!! info "Provided QuerySet" The provided queryset must be a valid Django queryset object, which is already available in the template context. #### Example In a report template which has a `PurchaseOrder` object available in its context as the variable `order`, return the matching line items ordered by part name: ```html {% raw %} {% load report %} {% order_queryset order.lines.all 'part__name' as ordered_lines %} ``` ### filter_queryset The `filter_queryset` function allows for arbitrary filtering of the provided queryset. It takes a queryset and a list of filter arguments, and returns a filtered queryset. ::: report.templatetags.report.filter_queryset options: show_docstring_description: false show_source: False !!! info "Provided QuerySet" The provided queryset must be a valid Django queryset object, which is already available in the template context. !!! warning "Advanced Users" The `filter_queryset` function is a powerful tool, but it is also easy to misuse. It assumes that the user has a good understanding of Django querysets and the underlying database structure. #### Example In a report template which has a `PurchaseOrder` object available in its context, fetch any line items which have a received quantity greater than zero: ```html {% raw %} {% load report %} {% filter_queryset order.lines.all received__gt=0 as received_lines %} {% endraw %} ``` ### filter_db_model The `filter_db_model` function allows for filtering of a database model based on a set of filter arguments. It takes a model class and a list of filter arguments, and returns a filtered queryset. ::: report.templatetags.report.filter_db_model options: show_docstring_description: false show_source: False #### Example Generate a list of all active customers: ```html {% raw %} {% load report %} {% filter_db_model 'company.company' is_customer=True active=True as active_customers %} {% endraw %} ``` ### Advanced Database Queries More advanced database filtering should be achieved using a [report plugin](../plugins/mixins/report.md), and adding custom context data to the report template. ## List Helpers The following helper functions are available for working with list (or list-like) data structures: ### length Return the length of a list (or list-like) data structure. Note that this will also work for other data structures which support the `len()` function, such as strings, dictionaries or querysets: ::: report.templatetags.report.length options: show_docstring_description: false show_source: False ### first Return the first element of a list (or list-like) data structure: ::: report.templatetags.report.first options: show_docstring_description: false show_source: False ### last Return the last element of a list (or list-like) data structure: ::: report.templatetags.report.last options: show_docstring_description: false show_source: False ### reverse Return a list (or list-like) data structure in reverse order: ::: report.templatetags.report.reverse options: show_docstring_description: false show_source: False ### truncate Return a truncated version of a list (or list-like) data structure, containing only the first N elements: ::: report.templatetags.report.truncate options: show_docstring_description: false show_source: False ## String Formatting ### strip Return a string with leading and trailing whitespace removed: ::: report.templatetags.report.strip options: show_docstring_description: false show_source: False ### lstrip Return a string with leading whitespace removed: ::: report.templatetags.report.lstrip options: show_docstring_description: false show_source: False ### rstrip Return a string with trailing whitespace removed: ::: report.templatetags.report.rstrip options: show_docstring_description: false show_source: False ### split Return a list of substrings by splitting a string based on a specified separator: ::: report.templatetags.report.split options: show_docstring_description: false show_source: False ### join Return a string by joining a list of strings into a single string, using a specified separator: ::: report.templatetags.report.join options: show_docstring_description: false show_source: False ### replace Return a string where occurrences of a specified substring are replaced with another substring: ::: report.templatetags.report.replace options: show_docstring_description: false show_source: False ### lowercase Return a string with all characters converted to lowercase: ::: report.templatetags.report.lowercase options: show_docstring_description: false show_source: False ### uppercase Return a string with all characters converted to uppercase: ::: report.templatetags.report.uppercase options: show_docstring_description: false show_source: False ### titlecase Return a string with the first character of each word converted to uppercase and the remaining characters converted to lowercase: ::: report.templatetags.report.titlecase options: show_docstring_description: false show_source: False ## Number Formatting A number of helper functions are available for formatting numbers in a particular way. These can be used to format numbers according to a particular number of decimal places, or to add leading zeros, for example. ### format_number The helper function `format_number` allows for some common number formatting options. It takes a number (or a number-like string) as an input, as well as some formatting arguments. It returns a *string* containing the formatted number: ::: report.templatetags.report.format_number options: show_docstring_description: false show_source: False #### Examples ```html {% raw %} {% load report %} {% format_number 3.14159265359 decimal_places=5 %} {% format_number 3.14159265359 decimal_places=5 leading=3 %} {% format_number 3.14159265359 integer=True %} {% format_number 9988776.5 decimal_places=2 separator=True %} {% format_number 9988776.5 decimal_places=2 separator=True locale='de-de' %} {% format_number 0.175 multiplier=100 decimal_places=1 %} {% format_number 1234.5 decimal_places=2 max_decimal_places=6 %} {% endraw %} ``` #### Custom Format Strings The `fmt` argument accepts a [Unicode number pattern](https://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns) string (the same syntax used by [Babel](https://babel.pocoo.org/en/latest/numbers.html)). When `fmt` is provided it takes complete priority over the `decimal_places`, `max_decimal_places`, `leading`, and `separator` arguments — those arguments are silently ignored. The `integer` and `multiplier` arguments **are** still applied to the number before the format string is used. | Symbol | Meaning | | --- | --- | | `0` | Required digit — always rendered, even if zero | | `#` | Optional digit — suppressed when not significant | | `,` | Grouping separator (position defines group size) | | `.` | Decimal separator | Common patterns: | Pattern | Example output | | --- | --- | | `0` | `1235` | | `#,##0` | `1,235` | | `0.00` | `1234.57` | | `#,##0.00` | `1,234.57` | | `000` | `007` | ```html {% raw %} {% load report %} {% format_number 1234.5678 fmt='0.00' %} {% format_number 1234.5678 fmt='#,##0.00' %} {% format_number 1234.5678 fmt='#,##0.00' locale='de-de' %} {% format_number 9988776655.4321 fmt='#,##0' integer=True %} {% endraw %} ``` ## Date Formatting For rendering date and datetime information, the following helper functions are available: Both functions resolve their output using the following priority order: 1. **`fmt=` argument** — a [strftime format string](https://docs.python.org/3/library/datetime.html#format-codes). When provided, this takes full priority; `locale` and `date_format` are ignored. 2. **`locale=` argument** — when no `fmt` is given, Babel formats the value using the style set by `date_format` (default `medium`). 3. **Server `LANGUAGE_CODE`** — used as the locale when no `locale=` argument is supplied. #### Date Format Styles The `date_format` argument controls how Babel renders the date when locale-aware formatting is used. The four named styles are: | Style | `format_date` example (en-us, 2025-01-12) | `format_datetime` example (en-us, 2025-01-12 14:30) | | --- | --- | --- | | `full` | `Sunday, January 12, 2025` | `Sunday, January 12, 2025 at 2:30:00 PM UTC` | | `long` | `January 12, 2025` | `January 12, 2025 at 2:30:00 PM UTC` | | `medium` *(default)* | `Jan 12, 2025` | `Jan 12, 2025, 2:30:00 PM` | | `short` | `1/12/25` | `1/12/25, 2:30 PM` | The exact output varies by locale — the table above uses `en-us`. ### format_date ::: report.templatetags.report.format_date options: show_docstring_description: false show_source: False #### Examples ```html {% raw %} {% load report %} {% format_date my_date %} {% format_date my_date fmt="%d/%m/%Y" %} {% format_date my_date locale='en-us' %} {% format_date my_date locale='en-us' date_format='short' %} {% format_date my_date locale='en-us' date_format='full' %} {% endraw %} ``` ### format_datetime ::: report.templatetags.report.format_datetime options: show_docstring_description: false show_source: False #### Examples ```html {% raw %} {% load report %} {% format_datetime my_datetime %} {% format_datetime my_datetime fmt="%d-%m-%Y %H:%M" %} {% format_datetime my_datetime locale='en-us' %} {% format_datetime my_datetime locale='de-de' date_format='short' %} {% format_datetime my_datetime timezone="Australia/Sydney" locale='en-au' %} {% endraw %} ``` ## Currency Formatting ### render_currency The helper function `render_currency` allows for simple rendering of currency data. This function can also convert the specified amount of currency into a different target currency: ::: report.templatetags.report.render_currency options: show_docstring_description: false show_source: False #### Decimal Places When no decimal place arguments are provided, the locale/currency standard is used (e.g. 2 places for USD, 0 for JPY). `decimal_places` and `max_decimal_places` work the same way as in [`format_number`](#format_number): | Argument | Effect | | --- | --- | | `decimal_places=N` | Forces exactly N decimal digits (zero-padded) | | `max_decimal_places=M` | Allows up to M decimal digits, suppressing trailing zeros beyond `decimal_places` | | Both set | Forced minimum of `decimal_places`, optional up to `max_decimal_places` | | Neither set | Locale/currency default (e.g. 2 for USD) | ```html {% raw %} {% load report %} {% render_currency order.total_price currency='USD' %} {% render_currency order.total_price currency='USD' decimal_places=3 %} {% render_currency order.total_price currency='USD' decimal_places=2 max_decimal_places=4 %} {% endraw %} ``` #### Locale and Symbol Rendering The locale controls how the currency symbol and separators are rendered. For example, `USD 1234.56` with various locales: | Locale | Output | | --- | --- | | `en-us` | `$1,234.56` | | `en-gb` | `US$1,234.56` | | `en-au` | `USD1,234.56` | | `de-de` | `1.234,56 $` | The locale is resolved in the following priority order: 1. **Explicit `locale=` argument** — highest priority, always wins 2. **Server `LANGUAGE_CODE`** — fallback #### Leading Digits The `leading` argument specifies the minimum number of digits to render before the decimal point (zero-padded). This works identically to `leading` in [`format_number`](#format_number): ```html {% raw %} {% load report %} {% render_currency order.total_price currency='USD' %} {% render_currency order.total_price currency='USD' leading=4 %} {% endraw %} ``` #### Custom Format Strings The `fmt` argument accepts a [Unicode number pattern](https://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns) string (same syntax as [`format_number`](#custom-format-strings)). **When `fmt` is provided, it takes complete priority over `decimal_places`, `max_decimal_places`, and `leading`** — those arguments are ignored. The `locale`, `currency`, `multiplier`, and `include_symbol` arguments are still applied when `fmt` is set. To include the currency symbol in a `fmt` pattern, use the `¤` placeholder. Without it, no symbol appears regardless of `include_symbol`. | Pattern | Example output (en-us, USD) | | --- | --- | | `#,##0.00` | `1,234.56` (no symbol) | | `¤#,##0.00` | `$1,234.56` | | `¤#,##0.0000` | `$1,234.5600` | | `¤ #,##0.00` | `$ 1,234.56` | ```html {% raw %} {% load report %} {% render_currency order.total_price currency='USD' fmt='#,##0.00' %} {% render_currency order.total_price currency='USD' fmt='¤#,##0.0000' locale='en-us' %} {% render_currency order.total_price currency='USD' fmt='#,##0.00' locale='de-de' %} {% render_currency order.total_price currency='USD' fmt='0.0000' decimal_places=2 %} {% endraw %} ``` #### Example ```html {% raw %} {% load report %} Line Item Unit Pricing: Total Price: {% render_currency order.total_price currency='NZD' decimal_places=2 %} Total Price: {% render_currency order.total_price currency='USD' locale='en-us' %} {% endraw %} ``` ### convert_currency To convert a currency value from one currency to another, use the `convert_currency` helper function: ::: report.templatetags.report.convert_currency options: show_docstring_description: false show_source: False !!! info "Data Types" The `money` parameter must be `Money` class instance. If not, an error will be raised. ### create_currency Create a `currency` instance using the `create_currency` helper function. This returns a `Money` class instance based on the provided amount and currency type. ::: report.templatetags.report.create_currency options: show_docstring_description: false show_source: False ## Maths Operations Simple mathematical operators are available, as demonstrated in the example template below. These operators can be used to perform basic arithmetic operations within the report template. !!! info "Input Types" These mathematical functions accept inputs of various input types, and attempt to perform the operation accordingly. Note that any inputs which are provided as strings or numbers will be converted to `Decimal` class types before the operation is performed. ### add Add two numbers together using the `add` helper function: ::: report.templatetags.report.add options: show_docstring_description: false show_source: False ### subtract Subtract one number from another using the `subtract` helper function: ::: report.templatetags.report.subtract options: show_docstring_description: false show_source: False ### multiply Multiply two numbers together using the `multiply` helper function: ::: report.templatetags.report.multiply options: show_docstring_description: false show_source: False ### divide Divide one number by another using the `divide` helper function: ::: report.templatetags.report.divide options: show_docstring_description: false show_source: False ### modulo Perform a modulo operation using the `modulo` helper function: ::: report.templatetags.report.modulo options: show_docstring_description: false show_source: False ### Example ```html {% raw %} {% load report %} {% add 1 3 %} {% subtract 4 3 %} {% multiply 1.2 3.4 %} {% divide 10 2 as division_result %} Division Result: {{ division_result }} {% endraw %} ``` These operators can also be used with variables: ```html {% raw %} {% load report %} {% for line in order.lines %} Total: {% multiply line.purchase_price line.quantity %}
{% endfor %} {% endraw %} ``` ## Media Files *Media files* are any files uploaded to the InvenTree server by the user. These are stored under the `/media/` directory and can be accessed for use in custom reports or labels. ### uploaded_image You can access an uploaded image file if you know the *path* of the image, relative to the top-level `/media/` directory. To load the image into a report, use the `{% raw %}{% uploaded_image ... %}{% endraw %}` tag: ::: report.templatetags.report.uploaded_image options: show_docstring_description: false show_source: False ```html {% raw %} {% load report %} {% endraw %} ``` !!! info "Missing Image" If the supplied image filename does not exist, it will be replaced with a placeholder image file !!! warning "Invalid Image" If the supplied file is not a valid image, it will be replaced with a placeholder image file #### Image Manipulation The `{% raw %}{% uploaded_image %}{% endraw %}` tag supports some optional parameters for image manipulation. These can be used to adjust or resize the image - to reduce the size of the generated report file, for example. ```html {% raw %} {% load report %} {% endraw %}``` ### encode_svg_image ::: report.templatetags.report.encode_svg_image options: show_docstring_description: false show_source: False SVG images need to be handled in a slightly different manner. When embedding an uploaded SVG image, use the `{% raw %}{% encode_svg_image ... %}{% endraw %}` tag: ```html {% raw %} {% load report %} {% endraw %} ``` ### part_image A shortcut function is provided for rendering an image associated with a Part instance. You can render the image of the part using the `{% raw %}{% part_image ... %}{% endraw %}` template tag: ::: report.templatetags.report.part_image options: show_docstring_description: false show_source: False ```html {% raw %} {% load report %} {% endraw %} ``` #### Image Arguments Any optional arguments which can be used in the [uploaded_image tag](#uploaded_image) can be used here too. #### Image Variations The *Part* model supports *preview* (256 x 256) and *thumbnail* (128 x 128) versions of the uploaded image. These variations can be used in the generated reports (e.g. to reduce generated file size): ```html {% raw %} {% load report %} {% endraw %} ``` ### company_image A shortcut function is provided for rendering an image associated with a Company instance. You can render the image of the company using the `{% raw %}{% company_image ... %}{% endraw %}` template tag: ::: report.templatetags.report.company_image options: show_docstring_description: false show_source: False ```html {% raw %} {% load report %} {% endraw %} ``` #### Image Variations *Preview* and *thumbnail* image variations can be rendered for the `company_image` tag, in a similar manner to [part image variations](#image-variations) ## Icons Some models (e.g. part categories and locations) allow to specify a custom icon. To render these icons in a report, there is a `{% raw %}{% icon location.icon %}{% endraw %}` template tag from the report template library available. This tag renders the required html for the icon. !!! info "Loading fonts" Additionally the icon fonts need to be loaded into the template. This can be done using the `{% raw %}{% include_icon_fonts %}{% endraw %}` template tag inside of a style block !!! tip "Custom classes for styling the icon further" The icon template tag accepts an optional `class` argument which can be used to apply a custom class to the rendered icon used to style the icon further e.g. positioning it, changing it's size, ... `{% raw %}{% icon location.icon class="my-class" %}{% endraw %}`. ```html {% raw %} {% load report %} {% block style %} {% include_icon_fonts %} {% endblock style %} {% icon location.icon %} {% endraw %} ``` ## InvenTree Logo A template tag is provided to load the InvenTree logo image into a report. You can render the logo using the `{% raw %}{% logo_image %}{% endraw %}` tag: ```html {% raw %} {% load report %} {% endraw %} ``` ### Custom Logo If the system administrator has enabled a [custom logo](../start/config.md#customization-options) then this logo will be used instead of the base InvenTree logo. This is a useful way to get a custom company logo into your reports. If you have a custom logo, but explicitly wish to load the InvenTree logo itself, add `custom=False` to the tag: ```html {% raw %} {% load report %} {% endraw %} ``` ## Report Assets [Report Assets](./assets.md) are files specifically uploaded by the user for inclusion in generated reports and labels. You can add asset images to the reports and labels by using the `{% raw %}{% asset ... %}{% endraw %}` template tag: ```html {% raw %} {% load report %} {% endraw %} ``` ## Parameters If you need to reference a parameter for a particular model instance, within the context of your template, you can use the `parameter` template tag: ### parameter This returns a [Parameter](../concepts/parameters.md) object which contains the value of the parameter, as well as any associated metadata (e.g. units, description, etc). ::: report.templatetags.report.parameter options: show_docstring_description: false show_source: False #### Example The following example assumes that you have a report or label which contains a valid [Part](../part/index.md) instance: ``` {% raw %} {% load report %} {% parameter part "length" as length %} Part: {{ part.name }}
Length: {{ length.data }} [{{ length.units }}] {% endraw %} ``` A [Parameter](../concepts/parameters.md) has the following available attributes: | Attribute | Description | | --- | --- | | Name | The *name* of the parameter (e.g. "Length") | | Description | The *description* of the parameter | | Data | The *value* of the parameter (e.g. "123.4") | | Units | The *units* of the parameter (e.g. "km") | | Template | A reference to a [ParameterTemplate](../concepts/parameters.md#parameter-templates) | ### parameter_value To access just the value of a parameter, use the `parameter_value` template tag: ::: report.templatetags.report.parameter_value options: show_docstring_description: false show_source: False #### Example ``` {% raw %} {% load report %} {% parameter_value part "length" backup_value="3"as length_value %} Part: {{ part.name }}
Length: {{ length_value }} {% endraw %} ``` ## Rendering Markdown Some data fields (such as the *Notes* field available on many internal database models) support [markdown formatting](https://en.wikipedia.org/wiki/Markdown). To render markdown content in a custom report, there are template filters made available through the [django-markdownify](https://github.com/erwinmatijsen/django-markdownify) library. This library provides functionality for converting markdown content to HTML representation, allowing it to be then rendered to PDF by the InvenTree report generation pipeline. To render markdown content in a report, consider the following simplified example: ```html {% raw %} {% load markdownify %}

Part Notes

{{ part.notes | markdownify }}

{% endraw %} ``` You can read further details in the [django-markdownify documentation](https://django-markdownify.readthedocs.io/en/latest/). ## List of tags and filters The following tags and filters are available. {{ tags_and_filters() }}