|
| 1 | +--- |
| 2 | +layout: post |
| 3 | +title: Events in Blazor Query Builder Component | Syncfusion |
| 4 | +description: Learn about the available events in the Syncfusion Blazor Query Builder, including the new Destroyed event that fires on component disposal. |
| 5 | +platform: Blazor |
| 6 | +control: Query Builder |
| 7 | +--- |
| 8 | + |
| 9 | +# Events in Blazor Query Builder Component |
| 10 | + |
| 11 | +This section lists key events available in the Blazor Query Builder and when they are triggered during user interactions and lifecycle changes. |
| 12 | + |
| 13 | +## Created |
| 14 | + |
| 15 | +The Created event is triggered once the component has been initialized and is ready. |
| 16 | + |
| 17 | +```cshtml |
| 18 | +<SfQueryBuilder TValue="Order" DataSource="@Data"> |
| 19 | + <QueryBuilderEvents TValue="Order" Created="OnCreated"></QueryBuilderEvents> |
| 20 | +</SfQueryBuilder> |
| 21 | +
|
| 22 | +@code { |
| 23 | + public void OnCreated() { |
| 24 | + // Here, you can customize your code. |
| 25 | + } |
| 26 | +} |
| 27 | +``` |
| 28 | + |
| 29 | +## RuleChanged |
| 30 | + |
| 31 | +The RuleChanged event is triggered whenever a rule or group is added, removed, or modified. |
| 32 | + |
| 33 | +```cshtml |
| 34 | +<SfQueryBuilder TValue="Order" DataSource="@Data"> |
| 35 | + <QueryBuilderEvents TValue="Order" RuleChanged="OnRuleChanged"></QueryBuilderEvents> |
| 36 | +</SfQueryBuilder> |
| 37 | +
|
| 38 | +@code { |
| 39 | + public void OnRuleChanged(RuleChangeEventArgs args) |
| 40 | + { |
| 41 | + // Here, you can customize your code. |
| 42 | + } |
| 43 | +} |
| 44 | +``` |
| 45 | +## Changed |
| 46 | + |
| 47 | +The Changed event is an EventCallback raised after a condition (And/Or), field, operator, or value change is applied in the Query Builder. |
| 48 | + |
| 49 | +```cshtml |
| 50 | +<SfQueryBuilder TValue="Order" DataSource="@Data"> |
| 51 | + <QueryBuilderEvents TValue="Order" Changed="OnChanged"></QueryBuilderEvents> |
| 52 | +</SfQueryBuilder> |
| 53 | +
|
| 54 | +@code { |
| 55 | + private void OnChanged(ChangeEventArgs args) |
| 56 | + { |
| 57 | + // Here, you can customize your code. |
| 58 | + } |
| 59 | +} |
| 60 | +``` |
| 61 | + |
| 62 | +## OnValueChange |
| 63 | + |
| 64 | +Raised before a condition (And/Or), field, operator, or value is changed. Use this to validate or react before committing a change. |
| 65 | + |
| 66 | +```cshtml |
| 67 | +<SfQueryBuilder TValue="Order" DataSource="@Data"> |
| 68 | + <QueryBuilderEvents TValue="Order" OnValueChange="OnValueChange"></QueryBuilderEvents> |
| 69 | +</SfQueryBuilder> |
| 70 | +
|
| 71 | +@code { |
| 72 | + private void OnValueChange(ChangeEventArgs args) |
| 73 | + { |
| 74 | + // Here, you can customize your code. |
| 75 | + } |
| 76 | +} |
| 77 | +``` |
| 78 | + |
| 79 | +## DataBound |
| 80 | + |
| 81 | +Triggered after the data source is populated and bound to the Query Builder. |
| 82 | + |
| 83 | +```cshtml |
| 84 | +<SfQueryBuilder TValue="Order" DataSource="@Data"> |
| 85 | + <QueryBuilderEvents TValue="Order" DataBound="OnDataBound"></QueryBuilderEvents> |
| 86 | +</SfQueryBuilder> |
| 87 | +
|
| 88 | +@code { |
| 89 | + private void OnDataBound(object args) |
| 90 | + { |
| 91 | + // Here, you can customize your code. |
| 92 | + } |
| 93 | +} |
| 94 | +``` |
| 95 | + |
| 96 | +## OnActionFailure |
| 97 | + |
| 98 | +The OnActionFailure event is triggered whenever a remote data request or action fails in the QueryBuilder. |
| 99 | + |
| 100 | +```cshtml |
| 101 | +<SfQueryBuilder TValue="Order" DataSource="@RemoteData"> |
| 102 | + <QueryBuilderEvents TValue="Order" OnActionFailure="OnActionFailure"></QueryBuilderEvents> |
| 103 | +</SfQueryBuilder> |
| 104 | +
|
| 105 | +@code { |
| 106 | + private void OnActionFailure(Exception ex) |
| 107 | + { |
| 108 | + // Here, you can customize your code. |
| 109 | + } |
| 110 | +} |
| 111 | +``` |
| 112 | + |
| 113 | +## Drag-and-drop events |
| 114 | + |
| 115 | +Enable drag-and-drop by setting the [`AllowDragAndDrop`](https://help.syncfusion.com/cr/blazor/Syncfusion.Blazor.QueryBuilder.SfQueryBuilder-1.html#Syncfusion_Blazor_QueryBuilder_SfQueryBuilder_1_AllowDragAndDrop) property to `true` (default is `false`). |
| 116 | + |
| 117 | +### RuleDragStarting |
| 118 | + |
| 119 | +This event is triggered **before** a rule or an entire group starts being dragged.The event arguments contain information about the dragged element. |
| 120 | + |
| 121 | +```cshtml |
| 122 | +<SfQueryBuilder TValue="Order" DataSource="@Data" AllowDragAndDrop="true"> |
| 123 | + <QueryBuilderEvents TValue="Order" RuleDragStarting="OnRuleDragStarting"></QueryBuilderEvents> |
| 124 | +</SfQueryBuilder> |
| 125 | +
|
| 126 | +@code { |
| 127 | + private void OnRuleDragStarting(RuleDragStartingEventArgs args) |
| 128 | + { |
| 129 | + // Here, you can customize your code. |
| 130 | + } |
| 131 | +} |
| 132 | +``` |
| 133 | + |
| 134 | +### RuleDropping |
| 135 | + |
| 136 | +The RuleDropping event fires just before the dragged rule or group is dropped onto a target location. You can use this event to validate the drop target or modify the drop behavior dynamically. |
| 137 | + |
| 138 | +```cshtml |
| 139 | +<SfQueryBuilder TValue="Order" DataSource="@Data" AllowDragAndDrop="true"> |
| 140 | + <QueryBuilderEvents TValue="Order" RuleDropping="OnRuleDropping"></QueryBuilderEvents> |
| 141 | +</SfQueryBuilder> |
| 142 | +
|
| 143 | +@code { |
| 144 | + private void OnRuleDropping(RuleDroppingEventArgs args) |
| 145 | + { |
| 146 | + // Here, you can customize your code. |
| 147 | + } |
| 148 | +} |
| 149 | +``` |
| 150 | + |
| 151 | +### RuleDropped |
| 152 | + |
| 153 | +This event is raised after a drag-and-drop operation has successfully completed and the query model has been updated. |
| 154 | + |
| 155 | +```cshtml |
| 156 | +<SfQueryBuilder TValue="Order" DataSource="@Data" AllowDragAndDrop="true"> |
| 157 | + <QueryBuilderEvents TValue="Order" RuleDropped="OnRuleDropped"></QueryBuilderEvents> |
| 158 | +</SfQueryBuilder> |
| 159 | +
|
| 160 | +@code { |
| 161 | + private void OnRuleDropped(RuleDroppedEventArgs args) |
| 162 | + { |
| 163 | + // Here, you can customize your code. |
| 164 | + } |
| 165 | +} |
| 166 | +``` |
| 167 | + |
| 168 | +## Destroyed |
| 169 | + |
| 170 | +The Destroyed event is triggered when the component is disposed. Use it to perform reliable cleanup, detach external resources, or finalize logging. |
| 171 | + |
| 172 | +```cshtml |
| 173 | +<SfQueryBuilder TValue="Order" DataSource="@Data"> |
| 174 | + <QueryBuilderEvents TValue="Order" Destroyed="OnDestroyed"></QueryBuilderEvents> |
| 175 | +</SfQueryBuilder> |
| 176 | +
|
| 177 | +@code { |
| 178 | + public void OnDestroyed(object args) |
| 179 | + { |
| 180 | + // Here, you can customize your code. |
| 181 | + } |
| 182 | +} |
| 183 | +``` |
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