Custom Filter

Description

You can also create your own Custom Filter with any html/css you want and/or jQuery library you wish to use. Angular template (component) are not supported at this point, if you wish to contribute on that end then I certainly accept PR (Pull Request).

Limitations

• as mentioned in the description, only html/css and/or jQuery libraries are supported.
  • this mainly mean that Angular templates (components) are not supported (feel free to contribute).
• SlickGrid uses table-cell as CSS for it to display a consistent height for each rows (this keeps the same row height/line-height to always be the same).
  • all this to say that you might be in a situation were your filter shows in the back of the grid. The best approach to overcome this is to use a modal if you can or if the library support append to body container. For example, you can see that multiple-select.js support a container and is needed for the filter to work as can be seen in the multipleSelectFilter.ts

Demo

Demo Page / Demo Client Component / Custom InputFilter.ts

How to use Custom Filter?

1. You first need to create a class using the Filter interface. Make sure to create all necessary public properties and functions.

• You can see a demo with a custom-inputFilter.ts that is used in the demo - example 4

2. Simply set the filter type to FilterType.custom and instantiate your class with new (can also pass DI in the constructor if you wish). Here is an example with a custom input filter:

// define you columns, in this demo Effort Driven will use a Select Filter
this.columnDefinitions = [      
  { id: 'title', name: 'Title', field: 'title' },
  { id: 'description', name: 'Description', field: 'description', type: FieldType.string,
    filterable: true, 
    filter: {
       type: FilterType.custom,
       customFilter: new CustomInputFilter() // create a new instance to make each Filter independent from each other
    }
  }
];

// you also need to enable the filters in the Grid Options
this.gridOptions = {
   enableFiltering: true
};

Default Search Term(s)

If you want to load the grid with certain default filter(s), you can use the following optional properties:

• searchTerm (single value) with singleSelect or select
• searchTerms (array of values) with multipleSelect

For example, setting a default value into an input element, you can simply get the search term with columnDef.filter.searchTerm and set the default value in jquery with $(filterElm).val(this.searchTerm);

Collection

If you want to pass a collection to your filter (for example, a multiple-select needs a select list of options), you can then use it in your custom filter through columnDef.filter.collection

key/label pair

By default a collection uses the label/value pair. You can loop through your collection and use the label/value properties. For example:

// loop through collection to create select option
this.columnDef.filter.collection.forEach((option: SelectOption) => {
  // use the option value & label
  options += `<option value="${option.value}">${option.label}</option>`;
});

Custom Structure (key/label pair)

What if your collection have totally different value/label pair? In this case, you can use the customStructure to change the property name(s) to use. You can change the label and/or the value, they can be passed independently. For example:

// use custom structure value/label pair
const labelName = (this.columnDef.filter.customStructure) ? this.columnDef.filter.customStructure.label : 'label';
const valueName = (this.columnDef.filter.customStructure) ? this.columnDef.filter.customStructure.value : 'value';

this.columnDef.filter.collection.forEach((option: SelectOption) => {
  // use the option value & translated label
  options += `<option value="${option[valueName]}">${option[labelName]}</option>`;
});

How to add Translation?

LabelKey

By default a collection uses the label/value pair without translation or labelKey/value pair with translation usage. So if you want to use translations, then you can loop through your collection and use the labelKey/value properties. For example:

this.columnDef.filter.collection.forEach((option: SelectOption) => {
  // translate label      
  const textLabel = (option.labelKey && typeof this.translate.instant === 'function') ? this.translate.instant(option.labelKey || ' ') : option.labelKey;

  // use the option value & translated label
  options += `<option value="${option.value}">${textLabel}</option>`;
});

Custom Structure with Translation

What if you want to use customStructure and translate the labels? Simply pass the flag enableTranslateLabel: true

For example:

// use custom structure value/label pair
const labelName = (this.columnDef.filter.customStructure) ? this.columnDef.filter.customStructure.label : 'label';
const valueName = (this.columnDef.filter.customStructure) ? this.columnDef.filter.customStructure.value : 'value';

this.columnDef.filter.collection.forEach((option: SelectOption) => {
  // translate label      
  const textLabel = (option.labelKey && typeof this.translate.instant === 'function') ? this.translate.instant(option[labelName] || ' ') : option[labelName];

  // use the option value & translated label
  options += `<option value="${option[valueName]}">${textLabel}</option>`;
});