1# Matching Rules of Explicit Want and Implicit Want 2 3Both explicit [Want](../reference/apis/js-apis-app-ability-want.md) and implicit [Want](../reference/apis/js-apis-app-ability-want.md) can be used to match an application component to start based on certain rules. These rules determine how the parameters set in [want](../reference/apis/js-apis-app-ability-want.md) match the configuration file declared by the target application component. 4 5## Matching Rules of Explicit Want 6 7 8The table below describes the matching rules of explicit [Want](../reference/apis/js-apis-app-ability-want.md). 9 10| Name| Type| Matching Item| Mandatory| Rule Description| 11| -------- | -------- | -------- | -------- | -------- | 12| deviceId | string | Yes| No| If this field is unspecified, only application components on the local device are matched.| 13| bundleName | string | Yes| Yes| If **abilityName** is specified but **bundleName** is unspecified, the matching fails.| 14| moduleName | string | Yes| No| If this field is unspecified and multiple modules with the same ability name exist in the application, the first application component is matched by default.| 15| abilityName | string | Yes| Yes| To use explicit Want, this field must be specified.| 16| uri | string | No| No| This field is not used for matching. It is passed to the target application component as a parameter.| 17| type | string | No| No| This field is not used for matching. It is passed to the target application component as a parameter.| 18| action | string | No| No| This field is not used for matching. It is passed to the target application component as a parameter.| 19| entities | Array<string> | No| No| This field is not used for matching. It is passed to the target application component as a parameter.| 20| flags | number | No| No| This field is not used for matching and is directly transferred to the system for processing. It is generally used to set runtime information, such as URI data authorization.| 21| parameters | {[key: string]: Object} | No| No| This field is not used for matching. It is passed to the target application component as a parameter.| 22 23## Matching Rules for Implicit Want 24 25The table below describes the matching rules of implicit [Want](../reference/apis/js-apis-app-ability-want.md). 26 27| Name | Type | Matching Item| Mandatory| Rule Description | 28| ----------- | ------------------------------ | ------ | ---- | ------------------------------------------------------------ | 29| deviceId | string | Yes | No | Implicit invoking is not supported across devices. | 30| abilityName | string | No | No | To use implicit Want, this field must be left unspecified. | 31| bundleName | string | Yes | No | - When only **bundleName** is specified, matching is limited to that application.<br>- When both **bundleName** and **moduleName** are specified, matching is limited to that module in that application.<br>- When only **moduleName** is specified, the setting is invalid.<br> <br>These fields will be used for implicit matching.| 32| moduleName | string | Yes | No | | 33| uri | string | Yes | No | | 34| type | string | Yes | No | | 35| action | string | Yes | No | | 36| entities | Array<string> | Yes | No | | 37| flags | number | No | No | This field is not used for matching and is directly transferred to the system for processing. It is generally used to set runtime information, such as URI data authorization.| 38| parameters | {[key: string]: Object} | No | No | This field is not used for matching. It is passed to the target application component as a parameter. | 39 40Get familiar with the following about implicit Want: 41 42 43- The **want** parameter passed by the caller indicates the operation to be performed by the caller. It also provides data and application type restrictions. 44 45- The **skills** field declares the capabilities of the target application component. For details, see [the skills tag](../quick-start/module-configuration-file.md#skills) in the [module.json5 file](../quick-start/module-configuration-file.md). 46 47 48The system matches the **want** parameter (including the **action**, **entities**, **uri**, and **type** attributes) passed by the caller against the **skills** configuration (including the **actions**, **entities**, **uris**, and **type** attributes) of the application components one by one. When all the four attributes are matched, a dialog box is displayed for users to select a matched application. 49 50 51### Matching Rules of action in the want Parameter 52 53The system matches the **action** attribute in the **want** parameter passed by the caller against **actions** under **skills** of the application components. 54 55- If **action** in the passed **want** parameter is unspecified and **actions** under **skills** of an application component is unspecified, the matching fails. 56 57- If **action** in the passed **want** parameter is specified but **actions** under **skills** of an application component is unspecified, the matching fails. 58 59- If **action** in the passed **want** parameter is unspecified but **actions** under **skills** of an application component is specified, the matching is successful. 60 61- If **action** in the passed **want** parameter is specified, and **actions** under **skills** of an application component is specified and contains **action** in the passed **want** parameter, the matching is successful. 62 63- If **action** in the passed **want** parameter is specified, and **actions** under **skills** of an application component is specified but does not contain **action** in the passed **want** parameter, the matching fails. 64 65 **Figure 1** Matching rules of action in the want parameter 66 67 68 69### Matching Rules of entities in the want Parameter 70 71The system matches the **entities** attribute in the **want** parameter passed by the caller against **entities** under **skills** of the application components. 72 73- If **entities** in the passed **want** parameter is unspecified but **entities** under **skills** of an application component is specified, the matching is successful. 74 75- If **entities** in the passed **want** parameter is unspecified but **entities** under **skills** of an application component is unspecified, the matching is successful. 76 77- If **entities** in the passed **want** parameter is specified but **entities** under **skills** of an application component is unspecified, the matching fails. 78 79- If **entities** in the passed **want** parameter is specified, and **entities** under **skills** of an application component is specified and contains **entities** in the passed **want** parameter, the matching is successful. 80 81- If **entities** in the passed **want** parameter is specified, and **entities** under **skills** of an application component is specified but does not contain **entities** in the passed **want** parameter, the matching fails. 82 83 **Figure 2** Matching rules of entities in the want parameter 84 85 86 87### Matching Rules of uri and type in the want Parameter 88 89When the **uri** and **type** parameters are specified in the **want** parameter to initiate an application component startup request, the system traverses the list of installed components and matches the **uris** array under **skills** of the application components one by one. If one of the **uris** arrays under **skills** matches the **uri** and **type** in the passed **want**, the matching is successful. 90 91There are four combinations of **uri** and **type** settings. The matching rules are as follows: 92 93- Neither **uri** or **type** is specified in the **want** parameter. 94 - If the **uris** array under **skills** of an application component is unspecified, the matching is successful. 95 - If the **uris** array under **skills** of an application component contains an URI element whose **scheme** and **type** are unspecified, the matching is successful. 96 - In other cases, the matching fails. 97 98- Only **uri** is specified in the **want** parameter. 99 - If the **uris** array under **skills** of an application component is unspecified, the matching fails. 100 - If the **uris** array under **skills** of an application component contains an element whose [uri is matched](#matching-rules-of-uri) and **type** is unspecified, the matching is successful. Otherwise, the matching fails. 101 - If the matching fails for the preceding two scenarios and the input URI is a file path URI, the system obtains the MIME type of the file based on the file name extension. If the MIME type matches **type** configured under **skills**, the matching is successful. 102 103- Only **type** is specified in the **want** parameter. 104 - If the **uris** array under **skills** of an application component is unspecified, the matching fails. 105 - If the **uris** array under **skills** of an application component contains an URI element whose **scheme** is unspecified and [type is matched](#matching-rules-of-type), the matching is successful. Otherwise, the matching fails. 106 107- Both **uri** and **type** are specified in the **want** parameter, as shown below. 108 - If the **uris** array under **skills** of an application component is unspecified, the matching fails. 109 - If the **uris** array under **skills** of an application component contains an element whose [uri is matched](#matching-rules-of-uri) and [type is matched](#matching-rules-of-type), the matching is successful. Otherwise, the matching fails. 110 111Leftmost URI matching: When only **scheme**, a combination of **scheme** and **host**, or a combination of **scheme**, **host**, and **port** is configured in the **uris** array under **skills** of the application component, the matching is successful only if the leftmost URI in the passed **want** parameter matches **scheme**, the combination of **scheme** and **host**, or the combination of **scheme**, **host**, and **port**. 112 113**Figure 3** Matching rules when uri and type are specified in the want parameter 114 115 116To simplify the description: 117 118- **uri** in the **want** parameter passed in by the caller is called **w_uri**; each element in the **uris** array under **skills** of the application component to match is called **s_uri**. 119- **type** in the **want** parameter passed in by the caller is called **w_type**; the type in the **uris** array under **skills** of the application component to match is called **s_type**. 120 121**Figure 4** Matching rules of uri and type in the want parameter 122 123 124 125### Matching Rules of uri 126 127The rules are as follows: 128 129- If **scheme** of **s_uri** is unspecified and **w_uri** is unspecified, the matching is successful. Otherwise, the matching fails. 130 131- If **host** of **s_uri** is unspecified and **scheme** of **w_uri** and **scheme** of **s_uri** are the same, the matching is successful. Otherwise, the matching fails. 132 133- If **port** of **s_uri** is unspecified and the combination of **scheme** and **host** of **w_uri** is the same as the combination of **scheme** and **host** of **s_uri**, the matching is successful. Otherwise, the matching fails. 134 135- If **path**, **pathStartWith**, and **pathRegex** of **s_uri** are unspecified and the combination of **scheme**, **host**, and **port** of **w_uri** is the same as the combination of **scheme**, **host**, and **port** of **s_uri**, the matching is successful. Otherwise, the matching fails. 136 137- If **path** of **s_uri** is specified and the **full path expressions** of **w_uri** and **s_uri** are the same, the matching is successful. Otherwise, the matching of **pathStartWith** continues. 138 139- If **pathStartWith** of **s_uri** is specified and **w_uri** contains the prefix expression of **s_uri**, the matching is successful. Otherwise, **pathRegex** matching continues. 140 141- If **pathRegex** of **s_uri** is specified and **w_uri** meets the regular expression of **s_uri**, the matching is successful. Otherwise, the matching fails. 142 143> **NOTE** 144> 145> The **scheme**, **host**, **port**, **path**, **pathStartWith**, and **pathRegex** attributes of **uris** under **skills** of an application component are concatenated. If **path**, **pathStartWith**, and **pathRegex** are declared in sequence, **uris** can be concatenated into the following expressions: 146> 147> - **Prefix URI expression**: When only **scheme**, a combination of **scheme** and **host**, or a combination of **scheme**, **host**, and **port** is configured in the configuration file, the matching is successful if a URI prefixed with the configuration file is passed in. 148> * `scheme://` 149> * `scheme://host` 150> * `scheme://host:port` 151> - **Full path expression**: `scheme://host:port/path` 152> - **Prefix expression**: `scheme://host:port/pathStartWith` 153> - **Regular expression**: `scheme://host:port/pathRegex` 154 155 156### Matching Rules of type 157 158> **NOTE** 159> 160> The matching rules of **type** described in this section are based on the fact that **type** in the **want** parameter is specified. If **type** is unspecified, follow the [matching rules of uri and type in the want parameter](#matching-rules-of-uri-and-type-in-the-want-parameter). 161 162The matching rules are as follows: 163 164- If **s_type** is unspecified, the matching fails. 165 166- If **s_type** or **w_type** contains the wildcard `*/*`, the matching is successful. 167 168- If the last character of **s_type** is the wildcard `*`, for example, `prefixType/*`, the matching is successful only when **w_type** contains `prefixType/`. 169 170- If the last character of **w_type** is the wildcard `*`, for example, `prefixType/*`, the matching is successful only when **s_type** contains `prefixType/`. 171
